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1.1       tron        1: <?xml version="1.0" encoding="iso-8859-1"?>
                      2: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
                      3:                       "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
                      4: <html>
                      5: <head>
                      6: <!-- Copyright 1999,2000 Clark Cooper <coopercc@netheaven.com>
                      7:      All rights reserved.
                      8:      This is free software. You may distribute or modify according to
                      9:      the terms of the MIT/X License -->
                     10:   <title>Expat XML Parser</title>
                     11:   <meta name="author" content="Clark Cooper, coopercc@netheaven.com" />
                     12:   <meta http-equiv="Content-Style-Type" content="text/css" />
                     13:   <link href="style.css" rel="stylesheet" type="text/css" />
                     14: </head>
                     15: <body>
                     16:   <table cellspacing="0" cellpadding="0" width="100%">
                     17:     <tr>
                     18:       <td class="corner"><img src="expat.png" alt="(Expat logo)" /></td>
                     19:       <td class="banner"><h1>The Expat XML Parser</h1></td>
                     20:     </tr>
                     21:     <tr>
                     22:       <td class="releaseno">Release 2.0.1</td>
                     23:       <td></td>
                     24:     </tr>
                     25:   </table>
                     26: <div class="content">
                     27:
                     28: <p>Expat is a library, written in C, for parsing XML documents. It's
                     29: the underlying XML parser for the open source Mozilla project, Perl's
                     30: <code>XML::Parser</code>, Python's <code>xml.parsers.expat</code>, and
                     31: other open-source XML parsers.</p>
                     32:
                     33: <p>This library is the creation of James Clark, who's also given us
                     34: groff (an nroff look-alike), Jade (an implemention of ISO's DSSSL
                     35: stylesheet language for SGML), XP (a Java XML parser package), XT (a
                     36: Java XSL engine).  James was also the technical lead on the XML
                     37: Working Group at W3C that produced the XML specification.</p>
                     38:
                     39: <p>This is free software, licensed under the <a
                     40: href="../COPYING">MIT/X Consortium license</a>. You may download it
                     41: from <a href="http://www.libexpat.org/">the Expat home page</a>.
                     42: </p>
                     43:
                     44: <p>The bulk of this document was originally commissioned as an article
                     45: by <a href="http://www.xml.com/">XML.com</a>. They graciously allowed
                     46: Clark Cooper to retain copyright and to distribute it with Expat.
                     47: This version has been substantially extended to include documentation
                     48: on features which have been added since the original article was
                     49: published, and additional information on using the original
                     50: interface.</p>
                     51:
                     52: <hr />
                     53: <h2>Table of Contents</h2>
                     54: <ul>
                     55:   <li><a href="#overview">Overview</a></li>
                     56:   <li><a href="#building">Building and Installing</a></li>
                     57:   <li><a href="#using">Using Expat</a></li>
                     58:   <li><a href="#reference">Reference</a>
                     59:   <ul>
                     60:     <li><a href="#creation">Parser Creation Functions</a>
                     61:     <ul>
                     62:       <li><a href="#XML_ParserCreate">XML_ParserCreate</a></li>
                     63:       <li><a href="#XML_ParserCreateNS">XML_ParserCreateNS</a></li>
                     64:       <li><a href="#XML_ParserCreate_MM">XML_ParserCreate_MM</a></li>
                     65:       <li><a href="#XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</a></li>
                     66:       <li><a href="#XML_ParserFree">XML_ParserFree</a></li>
                     67:       <li><a href="#XML_ParserReset">XML_ParserReset</a></li>
                     68:     </ul>
                     69:     </li>
                     70:     <li><a href="#parsing">Parsing Functions</a>
                     71:     <ul>
                     72:       <li><a href="#XML_Parse">XML_Parse</a></li>
                     73:       <li><a href="#XML_ParseBuffer">XML_ParseBuffer</a></li>
                     74:       <li><a href="#XML_GetBuffer">XML_GetBuffer</a></li>
                     75:       <li><a href="#XML_StopParser">XML_StopParser</a></li>
                     76:       <li><a href="#XML_ResumeParser">XML_ResumeParser</a></li>
                     77:       <li><a href="#XML_GetParsingStatus">XML_GetParsingStatus</a></li>
                     78:     </ul>
                     79:     </li>
                     80:     <li><a href="#setting">Handler Setting Functions</a>
                     81:     <ul>
                     82:       <li><a href="#XML_SetStartElementHandler">XML_SetStartElementHandler</a></li>
                     83:       <li><a href="#XML_SetEndElementHandler">XML_SetEndElementHandler</a></li>
                     84:       <li><a href="#XML_SetElementHandler">XML_SetElementHandler</a></li>
                     85:       <li><a href="#XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</a></li>
                     86:       <li><a href="#XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</a></li>
                     87:       <li><a href="#XML_SetCommentHandler">XML_SetCommentHandler</a></li>
                     88:       <li><a href="#XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</a></li>
                     89:       <li><a href="#XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</a></li>
                     90:       <li><a href="#XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</a></li>
                     91:       <li><a href="#XML_SetDefaultHandler">XML_SetDefaultHandler</a></li>
                     92:       <li><a href="#XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</a></li>
                     93:       <li><a href="#XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</a></li>
                     94:       <li><a href="#XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</a></li>
                     95:       <li><a href="#XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</a></li>
                     96:       <li><a href="#XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</a></li>
                     97:       <li><a href="#XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</a></li>
                     98:       <li><a href="#XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</a></li>
                     99:       <li><a href="#XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</a></li>
                    100:       <li><a href="#XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</a></li>
                    101:       <li><a href="#XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</a></li>
                    102:       <li><a href="#XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</a></li>
                    103:       <li><a href="#XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</a></li>
                    104:       <li><a href="#XML_SetElementDeclHandler">XML_SetElementDeclHandler</a></li>
                    105:       <li><a href="#XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</a></li>
                    106:       <li><a href="#XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</a></li>
                    107:       <li><a href="#XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</a></li>
                    108:       <li><a href="#XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</a></li>
                    109:       <li><a href="#XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</a></li>
                    110:     </ul>
                    111:     </li>
                    112:     <li><a href="#position">Parse Position and Error Reporting Functions</a>
                    113:     <ul>
                    114:       <li><a href="#XML_GetErrorCode">XML_GetErrorCode</a></li>
                    115:       <li><a href="#XML_ErrorString">XML_ErrorString</a></li>
                    116:       <li><a href="#XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</a></li>
                    117:       <li><a href="#XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</a></li>
                    118:       <li><a href="#XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</a></li>
                    119:       <li><a href="#XML_GetCurrentByteCount">XML_GetCurrentByteCount</a></li>
                    120:       <li><a href="#XML_GetInputContext">XML_GetInputContext</a></li>
                    121:     </ul>
                    122:     </li>
                    123:     <li><a href="#miscellaneous">Miscellaneous Functions</a>
                    124:     <ul>
                    125:       <li><a href="#XML_SetUserData">XML_SetUserData</a></li>
                    126:       <li><a href="#XML_GetUserData">XML_GetUserData</a></li>
                    127:       <li><a href="#XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</a></li>
                    128:       <li><a href="#XML_SetBase">XML_SetBase</a></li>
                    129:       <li><a href="#XML_GetBase">XML_GetBase</a></li>
                    130:       <li><a href="#XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</a></li>
                    131:       <li><a href="#XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</a></li>
1.1.1.2 ! spz       132:       <li><a href="#XML_GetAttributeInfo">XML_GetAttributeInfo</a></li>
1.1       tron      133:       <li><a href="#XML_SetEncoding">XML_SetEncoding</a></li>
                    134:       <li><a href="#XML_SetParamEntityParsing">XML_SetParamEntityParsing</a></li>
1.1.1.2 ! spz       135:       <li><a href="#XML_SetHashSalt">XML_SetHashSalt</a></li>
1.1       tron      136:       <li><a href="#XML_UseForeignDTD">XML_UseForeignDTD</a></li>
                    137:       <li><a href="#XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</a></li>
                    138:       <li><a href="#XML_DefaultCurrent">XML_DefaultCurrent</a></li>
                    139:       <li><a href="#XML_ExpatVersion">XML_ExpatVersion</a></li>
                    140:       <li><a href="#XML_ExpatVersionInfo">XML_ExpatVersionInfo</a></li>
                    141:       <li><a href="#XML_GetFeatureList">XML_GetFeatureList</a></li>
                    142:       <li><a href="#XML_FreeContentModel">XML_FreeContentModel</a></li>
                    143:       <li><a href="#XML_MemMalloc">XML_MemMalloc</a></li>
                    144:       <li><a href="#XML_MemRealloc">XML_MemRealloc</a></li>
                    145:       <li><a href="#XML_MemFree">XML_MemFree</a></li>
                    146:     </ul>
                    147:     </li>
                    148:   </ul>
                    149:   </li>
                    150: </ul>
                    151:
                    152: <hr />
                    153: <h2><a name="overview">Overview</a></h2>
                    154:
                    155: <p>Expat is a stream-oriented parser. You register callback (or
                    156: handler) functions with the parser and then start feeding it the
                    157: document.  As the parser recognizes parts of the document, it will
                    158: call the appropriate handler for that part (if you've registered one.)
                    159: The document is fed to the parser in pieces, so you can start parsing
                    160: before you have all the document. This also allows you to parse really
                    161: huge documents that won't fit into memory.</p>
                    162:
                    163: <p>Expat can be intimidating due to the many kinds of handlers and
                    164: options you can set. But you only need to learn four functions in
                    165: order to do 90% of what you'll want to do with it:</p>
                    166:
                    167: <dl>
                    168:
                    169: <dt><code><a href= "#XML_ParserCreate"
                    170:              >XML_ParserCreate</a></code></dt>
                    171:   <dd>Create a new parser object.</dd>
                    172:
                    173: <dt><code><a href= "#XML_SetElementHandler"
                    174:              >XML_SetElementHandler</a></code></dt>
                    175:   <dd>Set handlers for start and end tags.</dd>
                    176:
                    177: <dt><code><a href= "#XML_SetCharacterDataHandler"
                    178:              >XML_SetCharacterDataHandler</a></code></dt>
                    179:   <dd>Set handler for text.</dd>
                    180:
                    181: <dt><code><a href= "#XML_Parse"
                    182:              >XML_Parse</a></code></dt>
                    183:   <dd>Pass a buffer full of document to the parser</dd>
                    184: </dl>
                    185:
                    186: <p>These functions and others are described in the <a
                    187: href="#reference">reference</a> part of this document. The reference
                    188: section also describes in detail the parameters passed to the
                    189: different types of handlers.</p>
                    190:
                    191: <p>Let's look at a very simple example program that only uses 3 of the
                    192: above functions (it doesn't need to set a character handler.) The
                    193: program <a href="../examples/outline.c">outline.c</a> prints an
                    194: element outline, indenting child elements to distinguish them from the
                    195: parent element that contains them. The start handler does all the
                    196: work.  It prints two indenting spaces for every level of ancestor
                    197: elements, then it prints the element and attribute
                    198: information. Finally it increments the global <code>Depth</code>
                    199: variable.</p>
                    200:
                    201: <pre class="eg">
                    202: int Depth;
                    203:
                    204: void XMLCALL
                    205: start(void *data, const char *el, const char **attr) {
                    206:   int i;
                    207:
                    208:   for (i = 0; i &lt; Depth; i++)
                    209:     printf("  ");
                    210:
                    211:   printf("%s", el);
                    212:
                    213:   for (i = 0; attr[i]; i += 2) {
                    214:     printf(" %s='%s'", attr[i], attr[i + 1]);
                    215:   }
                    216:
                    217:   printf("\n");
                    218:   Depth++;
                    219: }  /* End of start handler */
                    220: </pre>
                    221:
                    222: <p>The end tag simply does the bookkeeping work of decrementing
                    223: <code>Depth</code>.</p>
                    224: <pre class="eg">
                    225: void XMLCALL
                    226: end(void *data, const char *el) {
                    227:   Depth--;
                    228: }  /* End of end handler */
                    229: </pre>
                    230:
                    231: <p>Note the <code>XMLCALL</code> annotation used for the callbacks.
                    232: This is used to ensure that the Expat and the callbacks are using the
                    233: same calling convention in case the compiler options used for Expat
                    234: itself and the client code are different.  Expat tries not to care
                    235: what the default calling convention is, though it may require that it
                    236: be compiled with a default convention of "cdecl" on some platforms.
                    237: For code which uses Expat, however, the calling convention is
                    238: specified by the <code>XMLCALL</code> annotation on most platforms;
                    239: callbacks should be defined using this annotation.</p>
                    240:
                    241: <p>The <code>XMLCALL</code> annotation was added in Expat 1.95.7, but
                    242: existing working Expat applications don't need to add it (since they
                    243: are already using the "cdecl" calling convention, or they wouldn't be
                    244: working).  The annotation is only needed if the default calling
                    245: convention may be something other than "cdecl".  To use the annotation
                    246: safely with older versions of Expat, you can conditionally define it
                    247: <em>after</em> including Expat's header file:</p>
                    248:
                    249: <pre class="eg">
                    250: #include &lt;expat.h&gt;
                    251:
                    252: #ifndef XMLCALL
                    253: #if defined(_MSC_EXTENSIONS) &amp;&amp; !defined(__BEOS__) &amp;&amp; !defined(__CYGWIN__)
                    254: #define XMLCALL __cdecl
                    255: #elif defined(__GNUC__)
                    256: #define XMLCALL __attribute__((cdecl))
                    257: #else
                    258: #define XMLCALL
                    259: #endif
                    260: #endif
                    261: </pre>
                    262:
                    263: <p>After creating the parser, the main program just has the job of
                    264: shoveling the document to the parser so that it can do its work.</p>
                    265:
                    266: <hr />
                    267: <h2><a name="building">Building and Installing Expat</a></h2>
                    268:
                    269: <p>The Expat distribution comes as a compressed (with GNU gzip) tar
                    270: file.  You may download the latest version from <a href=
                    271: "http://sourceforge.net/projects/expat/" >Source Forge</a>.  After
                    272: unpacking this, cd into the directory. Then follow either the Win32
                    273: directions or Unix directions below.</p>
                    274:
                    275: <h3>Building under Win32</h3>
                    276:
                    277: <p>If you're using the GNU compiler under cygwin, follow the Unix
                    278: directions in the next section. Otherwise if you have Microsoft's
                    279: Developer Studio installed, then from Windows Explorer double-click on
                    280: "expat.dsp" in the lib directory and build and install in the usual
                    281: manner.</p>
                    282:
                    283: <p>Alternatively, you may download the Win32 binary package that
                    284: contains the "expat.h" include file and a pre-built DLL.</p>
                    285:
                    286: <h3>Building under Unix (or GNU)</h3>
                    287:
                    288: <p>First you'll need to run the configure shell script in order to
                    289: configure the Makefiles and headers for your system.</p>
                    290:
                    291: <p>If you're happy with all the defaults that configure picks for you,
                    292: and you have permission on your system to install into /usr/local, you
                    293: can install Expat with this sequence of commands:</p>
                    294:
                    295: <pre class="eg">
                    296: ./configure
                    297: make
                    298: make install
                    299: </pre>
                    300:
                    301: <p>There are some options that you can provide to this script, but the
                    302: only one we'll mention here is the <code>--prefix</code> option. You
                    303: can find out all the options available by running configure with just
                    304: the <code>--help</code> option.</p>
                    305:
                    306: <p>By default, the configure script sets things up so that the library
                    307: gets installed in <code>/usr/local/lib</code> and the associated
                    308: header file in <code>/usr/local/include</code>.  But if you were to
                    309: give the option, <code>--prefix=/home/me/mystuff</code>, then the
                    310: library and header would get installed in
                    311: <code>/home/me/mystuff/lib</code> and
                    312: <code>/home/me/mystuff/include</code> respectively.</p>
                    313:
                    314: <h3>Configuring Expat Using the Pre-Processor</h3>
                    315:
                    316: <p>Expat's feature set can be configured using a small number of
                    317: pre-processor definitions.  The definition of this symbols does not
                    318: affect the set of entry points for Expat, only the behavior of the API
                    319: and the definition of character types in the case of
                    320: <code>XML_UNICODE_WCHAR_T</code>.  The symbols are:</p>
                    321:
                    322: <dl class="cpp-symbols">
                    323: <dt>XML_DTD</dt>
                    324: <dd>Include support for using and reporting DTD-based content.  If
                    325: this is defined, default attribute values from an external DTD subset
                    326: are reported and attribute value normalization occurs based on the
                    327: type of attributes defined in the external subset.  Without
                    328: this, Expat has a smaller memory footprint and can be faster, but will
                    329: not load external entities or process conditional sections.  This does
                    330: not affect the set of functions available in the API.</dd>
                    331:
                    332: <dt>XML_NS</dt>
                    333: <dd>When defined, support for the <cite><a href=
                    334: "http://www.w3.org/TR/REC-xml-names/" >Namespaces in XML</a></cite>
                    335: specification is included.</dd>
                    336:
                    337: <dt>XML_UNICODE</dt>
                    338: <dd>When defined, character data reported to the application is
                    339: encoded in UTF-16 using wide characters of the type
                    340: <code>XML_Char</code>.  This is implied if
                    341: <code>XML_UNICODE_WCHAR_T</code> is defined.</dd>
                    342:
                    343: <dt>XML_UNICODE_WCHAR_T</dt>
                    344: <dd>If defined, causes the <code>XML_Char</code> character type to be
                    345: defined using the <code>wchar_t</code> type; otherwise, <code>unsigned
                    346: short</code> is used.  Defining this implies
                    347: <code>XML_UNICODE</code>.</dd>
                    348:
                    349: <dt>XML_LARGE_SIZE</dt>
                    350: <dd>If defined, causes the <code>XML_Size</code> and <code>XML_Index</code>
                    351: integer types to be at least 64 bits in size. This is intended to support
                    352: processing of very large input streams, where the return values of
                    353: <code><a href="#XML_GetCurrentByteIndex" >XML_GetCurrentByteIndex</a></code>,
                    354: <code><a href="#XML_GetCurrentLineNumber" >XML_GetCurrentLineNumber</a></code> and
                    355: <code><a href="#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>
                    356: could overflow. It may not be supported by all compilers, and is turned
                    357: off by default.</dd>
                    358:
                    359: <dt>XML_CONTEXT_BYTES</dt>
                    360: <dd>The number of input bytes of markup context which the parser will
                    361: ensure are available for reporting via <code><a href=
                    362: "#XML_GetInputContext" >XML_GetInputContext</a></code>.  This is
                    363: normally set to 1024, and must be set to a positive interger.  If this
                    364: is not defined, the input context will not be available and <code><a
                    365: href= "#XML_GetInputContext" >XML_GetInputContext</a></code> will
                    366: always report NULL.  Without this, Expat has a smaller memory
                    367: footprint and can be faster.</dd>
                    368:
                    369: <dt>XML_STATIC</dt>
                    370: <dd>On Windows, this should be set if Expat is going to be linked
                    371: statically with the code that calls it; this is required to get all
                    372: the right MSVC magic annotations correct.  This is ignored on other
                    373: platforms.</dd>
1.1.1.2 ! spz       374:
        !           375: <dt>XML_ATTR_INFO</dt>
        !           376: <dd>If defined, makes the the additional function <code><a href=
        !           377: "#XML_GetAttributeInfo" >XML_GetAttributeInfo</a></code> available
        !           378: for reporting attribute byte offsets.</dd>
1.1       tron      379: </dl>
                    380:
                    381: <hr />
                    382: <h2><a name="using">Using Expat</a></h2>
                    383:
                    384: <h3>Compiling and Linking Against Expat</h3>
                    385:
                    386: <p>Unless you installed Expat in a location not expected by your
                    387: compiler and linker, all you have to do to use Expat in your programs
                    388: is to include the Expat header (<code>#include &lt;expat.h&gt;</code>)
                    389: in your files that make calls to it and to tell the linker that it
                    390: needs to link against the Expat library.  On Unix systems, this would
                    391: usually be done with the <code>-lexpat</code> argument.  Otherwise,
                    392: you'll need to tell the compiler where to look for the Expat header
                    393: and the linker where to find the Expat library.  You may also need to
                    394: take steps to tell the operating system where to find this library at
                    395: run time.</p>
                    396:
                    397: <p>On a Unix-based system, here's what a Makefile might look like when
                    398: Expat is installed in a standard location:</p>
                    399:
                    400: <pre class="eg">
                    401: CC=cc
                    402: LDFLAGS=
                    403: LIBS= -lexpat
                    404: xmlapp: xmlapp.o
                    405:         $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS)
                    406: </pre>
                    407:
                    408: <p>If you installed Expat in, say, <code>/home/me/mystuff</code>, then
                    409: the Makefile would look like this:</p>
                    410:
                    411: <pre class="eg">
                    412: CC=cc
                    413: CFLAGS= -I/home/me/mystuff/include
                    414: LDFLAGS=
                    415: LIBS= -L/home/me/mystuff/lib -lexpat
                    416: xmlapp: xmlapp.o
                    417:         $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS)
                    418: </pre>
                    419:
                    420: <p>You'd also have to set the environment variable
                    421: <code>LD_LIBRARY_PATH</code> to <code>/home/me/mystuff/lib</code> (or
                    422: to <code>${LD_LIBRARY_PATH}:/home/me/mystuff/lib</code> if
                    423: LD_LIBRARY_PATH already has some directories in it) in order to run
                    424: your application.</p>
                    425:
                    426: <h3>Expat Basics</h3>
                    427:
                    428: <p>As we saw in the example in the overview, the first step in parsing
                    429: an XML document with Expat is to create a parser object. There are <a
                    430: href="#creation">three functions</a> in the Expat API for creating a
                    431: parser object.  However, only two of these (<code><a href=
                    432: "#XML_ParserCreate" >XML_ParserCreate</a></code> and <code><a href=
                    433: "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>) can be used for
                    434: constructing a parser for a top-level document.  The object returned
                    435: by these functions is an opaque pointer (i.e. "expat.h" declares it as
                    436: void *) to data with further internal structure. In order to free the
                    437: memory associated with this object you must call <code><a href=
                    438: "#XML_ParserFree" >XML_ParserFree</a></code>. Note that if you have
                    439: provided any <a href="#userdata">user data</a> that gets stored in the
                    440: parser, then your application is responsible for freeing it prior to
                    441: calling <code>XML_ParserFree</code>.</p>
                    442:
                    443: <p>The objects returned by the parser creation functions are good for
                    444: parsing only one XML document or external parsed entity. If your
                    445: application needs to parse many XML documents, then it needs to create
                    446: a parser object for each one. The best way to deal with this is to
                    447: create a higher level object that contains all the default
                    448: initialization you want for your parser objects.</p>
                    449:
                    450: <p>Walking through a document hierarchy with a stream oriented parser
                    451: will require a good stack mechanism in order to keep track of current
                    452: context.  For instance, to answer the simple question, "What element
                    453: does this text belong to?" requires a stack, since the parser may have
                    454: descended into other elements that are children of the current one and
                    455: has encountered this text on the way out.</p>
                    456:
                    457: <p>The things you're likely to want to keep on a stack are the
                    458: currently opened element and it's attributes. You push this
                    459: information onto the stack in the start handler and you pop it off in
                    460: the end handler.</p>
                    461:
                    462: <p>For some tasks, it is sufficient to just keep information on what
                    463: the depth of the stack is (or would be if you had one.) The outline
                    464: program shown above presents one example. Another such task would be
                    465: skipping over a complete element. When you see the start tag for the
                    466: element you want to skip, you set a skip flag and record the depth at
                    467: which the element started.  When the end tag handler encounters the
                    468: same depth, the skipped element has ended and the flag may be
                    469: cleared. If you follow the convention that the root element starts at
                    470: 1, then you can use the same variable for skip flag and skip
                    471: depth.</p>
                    472:
                    473: <pre class="eg">
                    474: void
                    475: init_info(Parseinfo *info) {
                    476:   info->skip = 0;
                    477:   info->depth = 1;
                    478:   /* Other initializations here */
                    479: }  /* End of init_info */
                    480:
                    481: void XMLCALL
                    482: rawstart(void *data, const char *el, const char **attr) {
                    483:   Parseinfo *inf = (Parseinfo *) data;
                    484:
                    485:   if (! inf->skip) {
                    486:     if (should_skip(inf, el, attr)) {
                    487:       inf->skip = inf->depth;
                    488:     }
                    489:     else
                    490:       start(inf, el, attr);     /* This does rest of start handling */
                    491:   }
                    492:
                    493:   inf->depth++;
                    494: }  /* End of rawstart */
                    495:
                    496: void XMLCALL
                    497: rawend(void *data, const char *el) {
                    498:   Parseinfo *inf = (Parseinfo *) data;
                    499:
                    500:   inf->depth--;
                    501:
                    502:   if (! inf->skip)
                    503:     end(inf, el);              /* This does rest of end handling */
                    504:
                    505:   if (inf->skip == inf->depth)
                    506:     inf->skip = 0;
                    507: }  /* End rawend */
                    508: </pre>
                    509:
                    510: <p>Notice in the above example the difference in how depth is
                    511: manipulated in the start and end handlers. The end tag handler should
                    512: be the mirror image of the start tag handler. This is necessary to
                    513: properly model containment. Since, in the start tag handler, we
                    514: incremented depth <em>after</em> the main body of start tag code, then
                    515: in the end handler, we need to manipulate it <em>before</em> the main
                    516: body.  If we'd decided to increment it first thing in the start
                    517: handler, then we'd have had to decrement it last thing in the end
                    518: handler.</p>
                    519:
                    520: <h3 id="userdata">Communicating between handlers</h3>
                    521:
                    522: <p>In order to be able to pass information between different handlers
                    523: without using globals, you'll need to define a data structure to hold
                    524: the shared variables. You can then tell Expat (with the <code><a href=
                    525: "#XML_SetUserData" >XML_SetUserData</a></code> function) to pass a
                    526: pointer to this structure to the handlers.  This is the first
                    527: argument received by most handlers.  In the <a href="#reference"
                    528: >reference section</a>, an argument to a callback function is named
                    529: <code>userData</code> and have type <code>void *</code> if the user
                    530: data is passed; it will have the type <code>XML_Parser</code> if the
                    531: parser itself is passed.  When the parser is passed, the user data may
                    532: be retrieved using <code><a href="#XML_GetUserData"
                    533: >XML_GetUserData</a></code>.</p>
                    534:
                    535: <p>One common case where multiple calls to a single handler may need
                    536: to communicate using an application data structure is the case when
                    537: content passed to the character data handler (set by <code><a href=
                    538: "#XML_SetCharacterDataHandler"
                    539: >XML_SetCharacterDataHandler</a></code>) needs to be accumulated.  A
                    540: common first-time mistake with any of the event-oriented interfaces to
                    541: an XML parser is to expect all the text contained in an element to be
                    542: reported by a single call to the character data handler.  Expat, like
                    543: many other XML parsers, reports such data as a sequence of calls;
                    544: there's no way to know when the end of the sequence is reached until a
                    545: different callback is made.  A buffer referenced by the user data
                    546: structure proves both an effective and convenient place to accumulate
                    547: character data.</p>
                    548:
                    549: <!-- XXX example needed here -->
                    550:
                    551:
                    552: <h3>XML Version</h3>
                    553:
                    554: <p>Expat is an XML 1.0 parser, and as such never complains based on
                    555: the value of the <code>version</code> pseudo-attribute in the XML
                    556: declaration, if present.</p>
                    557:
                    558: <p>If an application needs to check the version number (to support
                    559: alternate processing), it should use the <code><a href=
                    560: "#XML_SetXmlDeclHandler" >XML_SetXmlDeclHandler</a></code> function to
                    561: set a handler that uses the information in the XML declaration to
                    562: determine what to do.  This example shows how to check that only a
                    563: version number of <code>"1.0"</code> is accepted:</p>
                    564:
                    565: <pre class="eg">
                    566: static int wrong_version;
                    567: static XML_Parser parser;
                    568:
                    569: static void XMLCALL
                    570: xmldecl_handler(void            *userData,
                    571:                 const XML_Char  *version,
                    572:                 const XML_Char  *encoding,
                    573:                 int              standalone)
                    574: {
                    575:   static const XML_Char Version_1_0[] = {'1', '.', '0', 0};
                    576:
                    577:   int i;
                    578:
                    579:   for (i = 0; i &lt; (sizeof(Version_1_0) / sizeof(Version_1_0[0])); ++i) {
                    580:     if (version[i] != Version_1_0[i]) {
                    581:       wrong_version = 1;
                    582:       /* also clear all other handlers: */
                    583:       XML_SetCharacterDataHandler(parser, NULL);
                    584:       ...
                    585:       return;
                    586:     }
                    587:   }
                    588:   ...
                    589: }
                    590: </pre>
                    591:
                    592: <h3>Namespace Processing</h3>
                    593:
                    594: <p>When the parser is created using the <code><a href=
                    595: "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, function, Expat
                    596: performs namespace processing. Under namespace processing, Expat
                    597: consumes <code>xmlns</code> and <code>xmlns:...</code> attributes,
                    598: which declare namespaces for the scope of the element in which they
                    599: occur. This means that your start handler will not see these
                    600: attributes.  Your application can still be informed of these
                    601: declarations by setting namespace declaration handlers with <a href=
                    602: "#XML_SetNamespaceDeclHandler"
                    603: ><code>XML_SetNamespaceDeclHandler</code></a>.</p>
                    604:
                    605: <p>Element type and attribute names that belong to a given namespace
                    606: are passed to the appropriate handler in expanded form. By default
                    607: this expanded form is a concatenation of the namespace URI, the
                    608: separator character (which is the 2nd argument to <code><a href=
                    609: "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>), and the local
                    610: name (i.e. the part after the colon). Names with undeclared prefixes
                    611: are not well-formed when namespace processing is enabled, and will
                    612: trigger an error. Unprefixed attribute names are never expanded,
                    613: and unprefixed element names are only expanded when they are in the
                    614: scope of a default namespace.</p>
                    615:
                    616: <p>However if <code><a href= "#XML_SetReturnNSTriplet"
                    617: >XML_SetReturnNSTriplet</a></code> has been called with a non-zero
                    618: <code>do_nst</code> parameter, then the expanded form for names with
                    619: an explicit prefix is a concatenation of: URI, separator, local name,
                    620: separator, prefix.</p>
                    621:
                    622: <p>You can set handlers for the start of a namespace declaration and
                    623: for the end of a scope of a declaration with the <code><a href=
                    624: "#XML_SetNamespaceDeclHandler" >XML_SetNamespaceDeclHandler</a></code>
                    625: function.  The StartNamespaceDeclHandler is called prior to the start
                    626: tag handler and the EndNamespaceDeclHandler is called after the
                    627: corresponding end tag that ends the namespace's scope.  The namespace
                    628: start handler gets passed the prefix and URI for the namespace.  For a
                    629: default namespace declaration (xmlns='...'), the prefix will be null.
                    630: The URI will be null for the case where the default namespace is being
                    631: unset.  The namespace end handler just gets the prefix for the closing
                    632: scope.</p>
                    633:
                    634: <p>These handlers are called for each declaration. So if, for
                    635: instance, a start tag had three namespace declarations, then the
                    636: StartNamespaceDeclHandler would be called three times before the start
                    637: tag handler is called, once for each declaration.</p>
                    638:
                    639: <h3>Character Encodings</h3>
                    640:
                    641: <p>While XML is based on Unicode, and every XML processor is required
                    642: to recognized UTF-8 and UTF-16 (1 and 2 byte encodings of Unicode),
                    643: other encodings may be declared in XML documents or entities. For the
                    644: main document, an XML declaration may contain an encoding
                    645: declaration:</p>
                    646: <pre>
                    647: &lt;?xml version="1.0" encoding="ISO-8859-2"?&gt;
                    648: </pre>
                    649:
                    650: <p>External parsed entities may begin with a text declaration, which
                    651: looks like an XML declaration with just an encoding declaration:</p>
                    652: <pre>
                    653: &lt;?xml encoding="Big5"?&gt;
                    654: </pre>
                    655:
                    656: <p>With Expat, you may also specify an encoding at the time of
                    657: creating a parser. This is useful when the encoding information may
                    658: come from a source outside the document itself (like a higher level
                    659: protocol.)</p>
                    660:
                    661: <p><a name="builtin_encodings"></a>There are four built-in encodings
                    662: in Expat:</p>
                    663: <ul>
                    664: <li>UTF-8</li>
                    665: <li>UTF-16</li>
                    666: <li>ISO-8859-1</li>
                    667: <li>US-ASCII</li>
                    668: </ul>
                    669:
                    670: <p>Anything else discovered in an encoding declaration or in the
                    671: protocol encoding specified in the parser constructor, triggers a call
                    672: to the <code>UnknownEncodingHandler</code>. This handler gets passed
                    673: the encoding name and a pointer to an <code>XML_Encoding</code> data
                    674: structure. Your handler must fill in this structure and return
                    675: <code>XML_STATUS_OK</code> if it knows how to deal with the
                    676: encoding. Otherwise the handler should return
                    677: <code>XML_STATUS_ERROR</code>.  The handler also gets passed a pointer
                    678: to an optional application data structure that you may indicate when
                    679: you set the handler.</p>
                    680:
                    681: <p>Expat places restrictions on character encodings that it can
                    682: support by filling in the <code>XML_Encoding</code> structure.
                    683: include file:</p>
                    684: <ol>
                    685: <li>Every ASCII character that can appear in a well-formed XML document
                    686: must be represented by a single byte, and that byte must correspond to
                    687: it's ASCII encoding (except for the characters $@\^'{}~)</li>
                    688: <li>Characters must be encoded in 4 bytes or less.</li>
                    689: <li>All characters encoded must have Unicode scalar values less than or
                    690: equal to 65535 (0xFFFF)<em>This does not apply to the built-in support
                    691: for UTF-16 and UTF-8</em></li>
                    692: <li>No character may be encoded by more that one distinct sequence of
                    693: bytes</li>
                    694: </ol>
                    695:
                    696: <p><code>XML_Encoding</code> contains an array of integers that
                    697: correspond to the 1st byte of an encoding sequence. If the value in
                    698: the array for a byte is zero or positive, then the byte is a single
                    699: byte encoding that encodes the Unicode scalar value contained in the
                    700: array. A -1 in this array indicates a malformed byte. If the value is
                    701: -2, -3, or -4, then the byte is the beginning of a 2, 3, or 4 byte
                    702: sequence respectively. Multi-byte sequences are sent to the convert
                    703: function pointed at in the <code>XML_Encoding</code> structure. This
                    704: function should return the Unicode scalar value for the sequence or -1
                    705: if the sequence is malformed.</p>
                    706:
                    707: <p>One pitfall that novice Expat users are likely to fall into is that
                    708: although Expat may accept input in various encodings, the strings that
                    709: it passes to the handlers are always encoded in UTF-8 or UTF-16
                    710: (depending on how Expat was compiled). Your application is responsible
                    711: for any translation of these strings into other encodings.</p>
                    712:
                    713: <h3>Handling External Entity References</h3>
                    714:
                    715: <p>Expat does not read or parse external entities directly. Note that
                    716: any external DTD is a special case of an external entity.  If you've
                    717: set no <code>ExternalEntityRefHandler</code>, then external entity
                    718: references are silently ignored. Otherwise, it calls your handler with
                    719: the information needed to read and parse the external entity.</p>
                    720:
                    721: <p>Your handler isn't actually responsible for parsing the entity, but
                    722: it is responsible for creating a subsidiary parser with <code><a href=
                    723: "#XML_ExternalEntityParserCreate"
                    724: >XML_ExternalEntityParserCreate</a></code> that will do the job. This
                    725: returns an instance of <code>XML_Parser</code> that has handlers and
                    726: other data structures initialized from the parent parser. You may then
                    727: use <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a
                    728: href= "#XML_ParseBuffer">XML_ParseBuffer</a></code> calls against this
                    729: parser.  Since external entities my refer to other external entities,
                    730: your handler should be prepared to be called recursively.</p>
                    731:
                    732: <h3>Parsing DTDs</h3>
                    733:
                    734: <p>In order to parse parameter entities, before starting the parse,
                    735: you must call <code><a href= "#XML_SetParamEntityParsing"
                    736: >XML_SetParamEntityParsing</a></code> with one of the following
                    737: arguments:</p>
                    738: <dl>
                    739: <dt><code>XML_PARAM_ENTITY_PARSING_NEVER</code></dt>
                    740: <dd>Don't parse parameter entities or the external subset</dd>
                    741: <dt><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></dt>
                    742: <dd>Parse parameter entites and the external subset unless
                    743: <code>standalone</code> was set to "yes" in the XML declaration.</dd>
                    744: <dt><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></dt>
                    745: <dd>Always parse parameter entities and the external subset</dd>
                    746: </dl>
                    747:
                    748: <p>In order to read an external DTD, you also have to set an external
                    749: entity reference handler as described above.</p>
                    750:
                    751: <h3 id="stop-resume">Temporarily Stopping Parsing</h3>
                    752:
                    753: <p>Expat 1.95.8 introduces a new feature: its now possible to stop
                    754: parsing temporarily from within a handler function, even if more data
                    755: has already been passed into the parser.  Applications for this
                    756: include</p>
                    757:
                    758: <ul>
                    759:   <li>Supporting the <a href= "http://www.w3.org/TR/xinclude/"
                    760:   >XInclude</a> specification.</li>
                    761:
                    762:   <li>Delaying further processing until additional information is
                    763:   available from some other source.</li>
                    764:
                    765:   <li>Adjusting processor load as task priorities shift within an
                    766:   application.</li>
                    767:
                    768:   <li>Stopping parsing completely (simply free or reset the parser
                    769:   instead of resuming in the outer parsing loop).  This can be useful
                    770:   if a application-domain error is found in the XML being parsed or if
                    771:   the result of the parse is determined not to be useful after
                    772:   all.</li>
                    773: </ul>
                    774:
                    775: <p>To take advantage of this feature, the main parsing loop of an
                    776: application needs to support this specifically.  It cannot be
                    777: supported with a parsing loop compatible with Expat 1.95.7 or
                    778: earlier (though existing loops will continue to work without
                    779: supporting the stop/resume feature).</p>
                    780:
                    781: <p>An application that uses this feature for a single parser will have
                    782: the rough structure (in pseudo-code):</p>
                    783:
                    784: <pre class="pseudocode">
                    785: fd = open_input()
                    786: p = create_parser()
                    787:
                    788: if parse_xml(p, fd) {
                    789:   /* suspended */
                    790:
                    791:   int suspended = 1;
                    792:
                    793:   while (suspended) {
                    794:     do_something_else()
                    795:     if ready_to_resume() {
                    796:       suspended = continue_parsing(p, fd);
                    797:     }
                    798:   }
                    799: }
                    800: </pre>
                    801:
                    802: <p>An application that may resume any of several parsers based on
                    803: input (either from the XML being parsed or some other source) will
                    804: certainly have more interesting control structures.</p>
                    805:
                    806: <p>This C function could be used for the <code>parse_xml</code>
                    807: function mentioned in the pseudo-code above:</p>
                    808:
                    809: <pre class="eg">
                    810: #define BUFF_SIZE 10240
                    811:
                    812: /* Parse a document from the open file descriptor 'fd' until the parse
                    813:    is complete (the document has been completely parsed, or there's
                    814:    been an error), or the parse is stopped.  Return non-zero when
                    815:    the parse is merely suspended.
                    816: */
                    817: int
                    818: parse_xml(XML_Parser p, int fd)
                    819: {
                    820:   for (;;) {
                    821:     int last_chunk;
                    822:     int bytes_read;
                    823:     enum XML_Status status;
                    824:
                    825:     void *buff = XML_GetBuffer(p, BUFF_SIZE);
                    826:     if (buff == NULL) {
                    827:       /* handle error... */
                    828:       return 0;
                    829:     }
                    830:     bytes_read = read(fd, buff, BUFF_SIZE);
                    831:     if (bytes_read &lt; 0) {
                    832:       /* handle error... */
                    833:       return 0;
                    834:     }
                    835:     status = XML_ParseBuffer(p, bytes_read, bytes_read == 0);
                    836:     switch (status) {
                    837:       case XML_STATUS_ERROR:
                    838:         /* handle error... */
                    839:         return 0;
                    840:       case XML_STATUS_SUSPENDED:
                    841:         return 1;
                    842:     }
                    843:     if (bytes_read == 0)
                    844:       return 0;
                    845:   }
                    846: }
                    847: </pre>
                    848:
                    849: <p>The corresponding <code>continue_parsing</code> function is
                    850: somewhat simpler, since it only need deal with the return code from
                    851: <code><a href= "#XML_ResumeParser">XML_ResumeParser</a></code>; it can
                    852: delegate the input handling to the <code>parse_xml</code>
                    853: function:</p>
                    854:
                    855: <pre class="eg">
                    856: /* Continue parsing a document which had been suspended.  The 'p' and
                    857:    'fd' arguments are the same as passed to parse_xml().  Return
                    858:    non-zero when the parse is suspended.
                    859: */
                    860: int
                    861: continue_parsing(XML_Parser p, int fd)
                    862: {
                    863:   enum XML_Status status = XML_ResumeParser(p);
                    864:   switch (status) {
                    865:     case XML_STATUS_ERROR:
                    866:       /* handle error... */
                    867:       return 0;
                    868:     case XML_ERROR_NOT_SUSPENDED:
                    869:       /* handle error... */
                    870:       return 0;.
                    871:     case XML_STATUS_SUSPENDED:
                    872:       return 1;
                    873:   }
                    874:   return parse_xml(p, fd);
                    875: }
                    876: </pre>
                    877:
                    878: <p>Now that we've seen what a mess the top-level parsing loop can
                    879: become, what have we gained?  Very simply, we can now use the <code><a
                    880: href= "#XML_StopParser" >XML_StopParser</a></code> function to stop
                    881: parsing, without having to go to great lengths to avoid additional
                    882: processing that we're expecting to ignore.  As a bonus, we get to stop
                    883: parsing <em>temporarily</em>, and come back to it when we're
                    884: ready.</p>
                    885:
                    886: <p>To stop parsing from a handler function, use the <code><a href=
                    887: "#XML_StopParser" >XML_StopParser</a></code> function.  This function
                    888: takes two arguments; the parser being stopped and a flag indicating
                    889: whether the parse can be resumed in the future.</p>
                    890:
                    891: <!-- XXX really need more here -->
                    892:
                    893:
                    894: <hr />
                    895: <!-- ================================================================ -->
                    896:
                    897: <h2><a name="reference">Expat Reference</a></h2>
                    898:
                    899: <h3><a name="creation">Parser Creation</a></h3>
                    900:
                    901: <pre class="fcndec" id="XML_ParserCreate">
                    902: XML_Parser XMLCALL
                    903: XML_ParserCreate(const XML_Char *encoding);
                    904: </pre>
                    905: <div class="fcndef">
                    906: Construct a new parser. If encoding is non-null, it specifies a
                    907: character encoding to use for the document. This overrides the document
                    908: encoding declaration. There are four built-in encodings:
                    909: <ul>
                    910: <li>US-ASCII</li>
                    911: <li>UTF-8</li>
                    912: <li>UTF-16</li>
                    913: <li>ISO-8859-1</li>
                    914: </ul>
                    915: Any other value will invoke a call to the UnknownEncodingHandler.
                    916: </div>
                    917:
                    918: <pre class="fcndec" id="XML_ParserCreateNS">
                    919: XML_Parser XMLCALL
                    920: XML_ParserCreateNS(const XML_Char *encoding,
                    921:                    XML_Char sep);
                    922: </pre>
                    923: <div class="fcndef">
                    924: Constructs a new parser that has namespace processing in effect. Namespace
                    925: expanded element names and attribute names are returned as a concatenation
                    926: of the namespace URI, <em>sep</em>, and the local part of the name. This
1.1.1.2 ! spz       927: means that you should pick a character for <em>sep</em> that can't be part
        !           928: of an URI. Since Expat does not check namespace URIs for conformance, the
        !           929: only safe choice for a namespace separator is a character that is illegal
        !           930: in XML. For instance, <code>'\xFF'</code> is not legal in UTF-8, and
        !           931: <code>'\xFFFF'</code> is not legal in UTF-16. There is a special case when
        !           932: <em>sep</em> is the null character <code>'\0'</code>: the namespace URI and
        !           933: the local part will be concatenated without any separator - this is intended
        !           934: to support RDF processors. It is a programming error to use the null separator
        !           935: with <a href= "#XML_SetReturnNSTriplet">namespace triplets</a>.</div>
1.1       tron      936:
                    937: <pre class="fcndec" id="XML_ParserCreate_MM">
                    938: XML_Parser XMLCALL
                    939: XML_ParserCreate_MM(const XML_Char *encoding,
                    940:                     const XML_Memory_Handling_Suite *ms,
                    941:                    const XML_Char *sep);
                    942: </pre>
                    943: <pre class="signature">
                    944: typedef struct {
                    945:   void *(XMLCALL *malloc_fcn)(size_t size);
                    946:   void *(XMLCALL *realloc_fcn)(void *ptr, size_t size);
                    947:   void (XMLCALL *free_fcn)(void *ptr);
                    948: } XML_Memory_Handling_Suite;
                    949: </pre>
                    950: <div class="fcndef">
                    951: <p>Construct a new parser using the suite of memory handling functions
                    952: specified in <code>ms</code>. If <code>ms</code> is NULL, then use the
                    953: standard set of memory management functions. If <code>sep</code> is
                    954: non NULL, then namespace processing is enabled in the created parser
                    955: and the character pointed at by sep is used as the separator between
                    956: the namespace URI and the local part of the name.</p>
                    957: </div>
                    958:
                    959: <pre class="fcndec" id="XML_ExternalEntityParserCreate">
                    960: XML_Parser XMLCALL
                    961: XML_ExternalEntityParserCreate(XML_Parser p,
                    962:                                const XML_Char *context,
                    963:                                const XML_Char *encoding);
                    964: </pre>
                    965: <div class="fcndef">
                    966: Construct a new <code>XML_Parser</code> object for parsing an external
                    967: general entity. Context is the context argument passed in a call to a
                    968: ExternalEntityRefHandler. Other state information such as handlers,
                    969: user data, namespace processing is inherited from the parser passed as
                    970: the 1st argument. So you shouldn't need to call any of the behavior
                    971: changing functions on this parser (unless you want it to act
                    972: differently than the parent parser).
                    973: </div>
                    974:
                    975: <pre class="fcndec" id="XML_ParserFree">
                    976: void XMLCALL
                    977: XML_ParserFree(XML_Parser p);
                    978: </pre>
                    979: <div class="fcndef">
                    980: Free memory used by the parser. Your application is responsible for
                    981: freeing any memory associated with <a href="#userdata">user data</a>.
                    982: </div>
                    983:
                    984: <pre class="fcndec" id="XML_ParserReset">
                    985: XML_Bool XMLCALL
                    986: XML_ParserReset(XML_Parser p,
                    987:                 const XML_Char *encoding);
                    988: </pre>
                    989: <div class="fcndef">
                    990: Clean up the memory structures maintained by the parser so that it may
                    991: be used again.  After this has been called, <code>parser</code> is
                    992: ready to start parsing a new document.  All handlers are cleared from
                    993: the parser, except for the unknownEncodingHandler.  The parser's external
                    994: state is re-initialized except for the values of ns and ns_triplets.
                    995: This function may not be used on a parser created using <code><a href=
                    996: "#XML_ExternalEntityParserCreate" >XML_ExternalEntityParserCreate</a
                    997: ></code>; it will return <code>XML_FALSE</code> in that case.  Returns
                    998: <code>XML_TRUE</code> on success.  Your application is responsible for
                    999: dealing with any memory associated with <a href="#userdata">user data</a>.
                   1000: </div>
                   1001:
                   1002: <h3><a name="parsing">Parsing</a></h3>
                   1003:
                   1004: <p>To state the obvious: the three parsing functions <code><a href=
                   1005: "#XML_Parse" >XML_Parse</a></code>, <code><a href= "#XML_ParseBuffer">
                   1006: XML_ParseBuffer</a></code> and <code><a href= "#XML_GetBuffer">
                   1007: XML_GetBuffer</a></code> must not be called from within a handler
                   1008: unless they operate on a separate parser instance, that is, one that
                   1009: did not call the handler. For example, it is OK to call the parsing
                   1010: functions from within an <code>XML_ExternalEntityRefHandler</code>,
                   1011: if they apply to the parser created by
                   1012: <code><a href= "#XML_ExternalEntityParserCreate"
                   1013: >XML_ExternalEntityParserCreate</a></code>.</p>
                   1014:
                   1015: <p>Note: the <code>len</code> argument passed to these functions
                   1016: should be considerably less than the maximum value for an integer,
                   1017: as it could create an integer overflow situation if the added
                   1018: lengths of a buffer and the unprocessed portion of the previous buffer
                   1019: exceed the maximum integer value. Input data at the end of a buffer
                   1020: will remain unprocessed if it is part of an XML token for which the
                   1021: end is not part of that buffer.</p>
                   1022:
                   1023: <pre class="fcndec" id="XML_Parse">
                   1024: enum XML_Status XMLCALL
                   1025: XML_Parse(XML_Parser p,
                   1026:           const char *s,
                   1027:           int len,
                   1028:           int isFinal);
                   1029: </pre>
                   1030: <pre class="signature">
                   1031: enum XML_Status {
                   1032:   XML_STATUS_ERROR = 0,
                   1033:   XML_STATUS_OK = 1
                   1034: };
                   1035: </pre>
                   1036: <div class="fcndef">
                   1037: Parse some more of the document. The string <code>s</code> is a buffer
                   1038: containing part (or perhaps all) of the document. The number of bytes of s
                   1039: that are part of the document is indicated by <code>len</code>. This means
                   1040: that <code>s</code> doesn't have to be null terminated. It also means that
                   1041: if <code>len</code> is larger than the number of bytes in the block of
                   1042: memory that <code>s</code> points at, then a memory fault is likely. The
                   1043: <code>isFinal</code> parameter informs the parser that this is the last
                   1044: piece of the document. Frequently, the last piece is empty (i.e.
                   1045: <code>len</code> is zero.)
                   1046: If a parse error occurred, it returns <code>XML_STATUS_ERROR</code>.
                   1047: Otherwise it returns <code>XML_STATUS_OK</code> value.
                   1048: </div>
                   1049:
                   1050: <pre class="fcndec" id="XML_ParseBuffer">
                   1051: enum XML_Status XMLCALL
                   1052: XML_ParseBuffer(XML_Parser p,
                   1053:                 int len,
                   1054:                 int isFinal);
                   1055: </pre>
                   1056: <div class="fcndef">
                   1057: This is just like <code><a href= "#XML_Parse" >XML_Parse</a></code>,
                   1058: except in this case Expat provides the buffer.  By obtaining the
                   1059: buffer from Expat with the <code><a href= "#XML_GetBuffer"
                   1060: >XML_GetBuffer</a></code> function, the application can avoid double
                   1061: copying of the input.
                   1062: </div>
                   1063:
                   1064: <pre class="fcndec" id="XML_GetBuffer">
                   1065: void * XMLCALL
                   1066: XML_GetBuffer(XML_Parser p,
                   1067:               int len);
                   1068: </pre>
                   1069: <div class="fcndef">
                   1070: Obtain a buffer of size <code>len</code> to read a piece of the document
                   1071: into. A NULL value is returned if Expat can't allocate enough memory for
                   1072: this buffer. This has to be called prior to every call to
                   1073: <code><a href= "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. A
                   1074: typical use would look like this:
                   1075:
                   1076: <pre class="eg">
                   1077: for (;;) {
                   1078:   int bytes_read;
                   1079:   void *buff = XML_GetBuffer(p, BUFF_SIZE);
                   1080:   if (buff == NULL) {
                   1081:     /* handle error */
                   1082:   }
                   1083:
                   1084:   bytes_read = read(docfd, buff, BUFF_SIZE);
                   1085:   if (bytes_read &lt; 0) {
                   1086:     /* handle error */
                   1087:   }
                   1088:
                   1089:   if (! XML_ParseBuffer(p, bytes_read, bytes_read == 0)) {
                   1090:     /* handle parse error */
                   1091:   }
                   1092:
                   1093:   if (bytes_read == 0)
                   1094:     break;
                   1095: }
                   1096: </pre>
                   1097: </div>
                   1098:
                   1099: <pre class="fcndec" id="XML_StopParser">
                   1100: enum XML_Status XMLCALL
                   1101: XML_StopParser(XML_Parser p,
                   1102:                XML_Bool resumable);
                   1103: </pre>
                   1104: <div class="fcndef">
                   1105:
                   1106: <p>Stops parsing, causing <code><a href= "#XML_Parse"
                   1107: >XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer"
                   1108: >XML_ParseBuffer</a></code> to return.  Must be called from within a
                   1109: call-back handler, except when aborting (when <code>resumable</code>
                   1110: is <code>XML_FALSE</code>) an already suspended parser.  Some
                   1111: call-backs may still follow because they would otherwise get
                   1112: lost, including
                   1113: <ul>
                   1114:   <li> the end element handler for empty elements when stopped in the
                   1115:        start element handler,</li>
                   1116:   <li> the end namespace declaration handler when stopped in the end
                   1117:        element handler,</li>
                   1118:   <li> the character data handler when stopped in the character data handler
                   1119:        while making multiple call-backs on a contiguous chunk of characters,</li>
                   1120: </ul>
                   1121: and possibly others.</p>
                   1122:
                   1123: <p>This can be called from most handlers, including DTD related
                   1124: call-backs, except when parsing an external parameter entity and
                   1125: <code>resumable</code> is <code>XML_TRUE</code>.  Returns
                   1126: <code>XML_STATUS_OK</code> when successful,
                   1127: <code>XML_STATUS_ERROR</code> otherwise.  The possible error codes
                   1128: are:</p>
                   1129: <dl>
                   1130:   <dt><code>XML_ERROR_SUSPENDED</code></dt>
                   1131:   <dd>when suspending an already suspended parser.</dd>
                   1132:   <dt><code>XML_ERROR_FINISHED</code></dt>
                   1133:   <dd>when the parser has already finished.</dd>
                   1134:   <dt><code>XML_ERROR_SUSPEND_PE</code></dt>
                   1135:   <dd>when suspending while parsing an external PE.</dd>
                   1136: </dl>
                   1137:
                   1138: <p>Since the stop/resume feature requires application support in the
                   1139: outer parsing loop, it is an error to call this function for a parser
                   1140: not being handled appropriately; see <a href= "#stop-resume"
                   1141: >Temporarily Stopping Parsing</a> for more information.</p>
                   1142:
                   1143: <p>When <code>resumable</code> is <code>XML_TRUE</code> then parsing
                   1144: is <em>suspended</em>, that is, <code><a href= "#XML_Parse"
                   1145: >XML_Parse</a></code> and <code><a href= "#XML_ParseBuffer"
                   1146: >XML_ParseBuffer</a></code> return <code>XML_STATUS_SUSPENDED</code>.
                   1147: Otherwise, parsing is <em>aborted</em>, that is, <code><a href=
                   1148: "#XML_Parse" >XML_Parse</a></code> and <code><a href=
                   1149: "#XML_ParseBuffer" >XML_ParseBuffer</a></code> return
                   1150: <code>XML_STATUS_ERROR</code> with error code
                   1151: <code>XML_ERROR_ABORTED</code>.</p>
                   1152:
                   1153: <p><strong>Note:</strong>
                   1154: This will be applied to the current parser instance only, that is, if
                   1155: there is a parent parser then it will continue parsing when the
                   1156: external entity reference handler returns.  It is up to the
                   1157: implementation of that handler to call <code><a href=
                   1158: "#XML_StopParser" >XML_StopParser</a></code> on the parent parser
                   1159: (recursively), if one wants to stop parsing altogether.</p>
                   1160:
                   1161: <p>When suspended, parsing can be resumed by calling <code><a href=
                   1162: "#XML_ResumeParser" >XML_ResumeParser</a></code>.</p>
                   1163:
                   1164: <p>New in Expat 1.95.8.</p>
                   1165: </div>
                   1166:
                   1167: <pre class="fcndec" id="XML_ResumeParser">
                   1168: enum XML_Status XMLCALL
                   1169: XML_ResumeParser(XML_Parser p);
                   1170: </pre>
                   1171: <div class="fcndef">
                   1172: <p>Resumes parsing after it has been suspended with <code><a href=
                   1173: "#XML_StopParser" >XML_StopParser</a></code>.  Must not be called from
                   1174: within a handler call-back.  Returns same status codes as <code><a
                   1175: href= "#XML_Parse">XML_Parse</a></code> or <code><a href=
                   1176: "#XML_ParseBuffer" >XML_ParseBuffer</a></code>.  An additional error
                   1177: code, <code>XML_ERROR_NOT_SUSPENDED</code>, will be returned if the
                   1178: parser was not currently suspended.</p>
                   1179:
                   1180: <p><strong>Note:</strong>
                   1181: This must be called on the most deeply nested child parser instance
                   1182: first, and on its parent parser only after the child parser has
                   1183: finished, to be applied recursively until the document entity's parser
                   1184: is restarted.  That is, the parent parser will not resume by itself
                   1185: and it is up to the application to call <code><a href=
                   1186: "#XML_ResumeParser" >XML_ResumeParser</a></code> on it at the
                   1187: appropriate moment.</p>
                   1188:
                   1189: <p>New in Expat 1.95.8.</p>
                   1190: </div>
                   1191:
                   1192: <pre class="fcndec" id="XML_GetParsingStatus">
                   1193: void XMLCALL
                   1194: XML_GetParsingStatus(XML_Parser p,
                   1195:                      XML_ParsingStatus *status);
                   1196: </pre>
                   1197: <pre class="signature">
                   1198: enum XML_Parsing {
                   1199:   XML_INITIALIZED,
                   1200:   XML_PARSING,
                   1201:   XML_FINISHED,
                   1202:   XML_SUSPENDED
                   1203: };
                   1204:
                   1205: typedef struct {
                   1206:   enum XML_Parsing parsing;
                   1207:   XML_Bool finalBuffer;
                   1208: } XML_ParsingStatus;
                   1209: </pre>
                   1210: <div class="fcndef">
                   1211: <p>Returns status of parser with respect to being initialized,
                   1212: parsing, finished, or suspended, and whether the final buffer is being
                   1213: processed.  The <code>status</code> parameter <em>must not</em> be
                   1214: NULL.</p>
                   1215:
                   1216: <p>New in Expat 1.95.8.</p>
                   1217: </div>
                   1218:
                   1219:
                   1220: <h3><a name="setting">Handler Setting</a></h3>
                   1221:
                   1222: <p>Although handlers are typically set prior to parsing and left alone, an
                   1223: application may choose to set or change the handler for a parsing event
                   1224: while the parse is in progress. For instance, your application may choose
                   1225: to ignore all text not descended from a <code>para</code> element. One
                   1226: way it could do this is to set the character handler when a para start tag
                   1227: is seen, and unset it for the corresponding end tag.</p>
                   1228:
                   1229: <p>A handler may be <em>unset</em> by providing a NULL pointer to the
                   1230: appropriate handler setter. None of the handler setting functions have
                   1231: a return value.</p>
                   1232:
                   1233: <p>Your handlers will be receiving strings in arrays of type
                   1234: <code>XML_Char</code>. This type is conditionally defined in expat.h as
                   1235: either <code>char</code>, <code>wchar_t</code> or <code>unsigned short</code>.
                   1236: The former implies UTF-8 encoding, the latter two imply UTF-16 encoding.
                   1237: Note that you'll receive them in this form independent of the original
                   1238: encoding of the document.</p>
                   1239:
                   1240: <div class="handler">
                   1241: <pre class="setter" id="XML_SetStartElementHandler">
                   1242: void XMLCALL
                   1243: XML_SetStartElementHandler(XML_Parser p,
                   1244:                            XML_StartElementHandler start);
                   1245: </pre>
                   1246: <pre class="signature">
                   1247: typedef void
                   1248: (XMLCALL *XML_StartElementHandler)(void *userData,
                   1249:                                    const XML_Char *name,
                   1250:                                    const XML_Char **atts);
                   1251: </pre>
                   1252: <p>Set handler for start (and empty) tags. Attributes are passed to the start
                   1253: handler as a pointer to a vector of char pointers. Each attribute seen in
                   1254: a start (or empty) tag occupies 2 consecutive places in this vector: the
                   1255: attribute name followed by the attribute value. These pairs are terminated
                   1256: by a null pointer.</p>
                   1257: <p>Note that an empty tag generates a call to both start and end handlers
                   1258: (in that order).</p>
                   1259: </div>
                   1260:
                   1261: <div class="handler">
                   1262: <pre class="setter" id="XML_SetEndElementHandler">
                   1263: void XMLCALL
                   1264: XML_SetEndElementHandler(XML_Parser p,
                   1265:                          XML_EndElementHandler);
                   1266: </pre>
                   1267: <pre class="signature">
                   1268: typedef void
                   1269: (XMLCALL *XML_EndElementHandler)(void *userData,
                   1270:                                  const XML_Char *name);
                   1271: </pre>
                   1272: <p>Set handler for end (and empty) tags. As noted above, an empty tag
                   1273: generates a call to both start and end handlers.</p>
                   1274: </div>
                   1275:
                   1276: <div class="handler">
                   1277: <pre class="setter" id="XML_SetElementHandler">
                   1278: void XMLCALL
                   1279: XML_SetElementHandler(XML_Parser p,
                   1280:                       XML_StartElementHandler start,
                   1281:                       XML_EndElementHandler end);
                   1282: </pre>
                   1283: <p>Set handlers for start and end tags with one call.</p>
                   1284: </div>
                   1285:
                   1286: <div class="handler">
                   1287: <pre class="setter" id="XML_SetCharacterDataHandler">
                   1288: void XMLCALL
                   1289: XML_SetCharacterDataHandler(XML_Parser p,
                   1290:                             XML_CharacterDataHandler charhndl)
                   1291: </pre>
                   1292: <pre class="signature">
                   1293: typedef void
                   1294: (XMLCALL *XML_CharacterDataHandler)(void *userData,
                   1295:                                     const XML_Char *s,
                   1296:                                     int len);
                   1297: </pre>
                   1298: <p>Set a text handler. The string your handler receives
                   1299: is <em>NOT nul-terminated</em>. You have to use the length argument
                   1300: to deal with the end of the string. A single block of contiguous text
                   1301: free of markup may still result in a sequence of calls to this handler.
                   1302: In other words, if you're searching for a pattern in the text, it may
                   1303: be split across calls to this handler. Note: Setting this handler to NULL
                   1304: may <em>NOT immediately</em> terminate call-backs if the parser is currently
                   1305: processing such a single block of contiguous markup-free text, as the parser
                   1306: will continue calling back until the end of the block is reached.</p>
                   1307: </div>
                   1308:
                   1309: <div class="handler">
                   1310: <pre class="setter" id="XML_SetProcessingInstructionHandler">
                   1311: void XMLCALL
                   1312: XML_SetProcessingInstructionHandler(XML_Parser p,
                   1313:                                     XML_ProcessingInstructionHandler proc)
                   1314: </pre>
                   1315: <pre class="signature">
                   1316: typedef void
                   1317: (XMLCALL *XML_ProcessingInstructionHandler)(void *userData,
                   1318:                                             const XML_Char *target,
                   1319:                                             const XML_Char *data);
                   1320:
                   1321: </pre>
                   1322: <p>Set a handler for processing instructions. The target is the first word
                   1323: in the processing instruction. The data is the rest of the characters in
                   1324: it after skipping all whitespace after the initial word.</p>
                   1325: </div>
                   1326:
                   1327: <div class="handler">
                   1328: <pre class="setter" id="XML_SetCommentHandler">
                   1329: void XMLCALL
                   1330: XML_SetCommentHandler(XML_Parser p,
                   1331:                       XML_CommentHandler cmnt)
                   1332: </pre>
                   1333: <pre class="signature">
                   1334: typedef void
                   1335: (XMLCALL *XML_CommentHandler)(void *userData,
                   1336:                               const XML_Char *data);
                   1337: </pre>
                   1338: <p>Set a handler for comments. The data is all text inside the comment
                   1339: delimiters.</p>
                   1340: </div>
                   1341:
                   1342: <div class="handler">
                   1343: <pre class="setter" id="XML_SetStartCdataSectionHandler">
                   1344: void XMLCALL
                   1345: XML_SetStartCdataSectionHandler(XML_Parser p,
                   1346:                                 XML_StartCdataSectionHandler start);
                   1347: </pre>
                   1348: <pre class="signature">
                   1349: typedef void
                   1350: (XMLCALL *XML_StartCdataSectionHandler)(void *userData);
                   1351: </pre>
                   1352: <p>Set a handler that gets called at the beginning of a CDATA section.</p>
                   1353: </div>
                   1354:
                   1355: <div class="handler">
                   1356: <pre class="setter" id="XML_SetEndCdataSectionHandler">
                   1357: void XMLCALL
                   1358: XML_SetEndCdataSectionHandler(XML_Parser p,
                   1359:                               XML_EndCdataSectionHandler end);
                   1360: </pre>
                   1361: <pre class="signature">
                   1362: typedef void
                   1363: (XMLCALL *XML_EndCdataSectionHandler)(void *userData);
                   1364: </pre>
                   1365: <p>Set a handler that gets called at the end of a CDATA section.</p>
                   1366: </div>
                   1367:
                   1368: <div class="handler">
                   1369: <pre class="setter" id="XML_SetCdataSectionHandler">
                   1370: void XMLCALL
                   1371: XML_SetCdataSectionHandler(XML_Parser p,
                   1372:                            XML_StartCdataSectionHandler start,
                   1373:                            XML_EndCdataSectionHandler end)
                   1374: </pre>
                   1375: <p>Sets both CDATA section handlers with one call.</p>
                   1376: </div>
                   1377:
                   1378: <div class="handler">
                   1379: <pre class="setter" id="XML_SetDefaultHandler">
                   1380: void XMLCALL
                   1381: XML_SetDefaultHandler(XML_Parser p,
                   1382:                       XML_DefaultHandler hndl)
                   1383: </pre>
                   1384: <pre class="signature">
                   1385: typedef void
                   1386: (XMLCALL *XML_DefaultHandler)(void *userData,
                   1387:                               const XML_Char *s,
                   1388:                               int len);
                   1389: </pre>
                   1390:
                   1391: <p>Sets a handler for any characters in the document which wouldn't
                   1392: otherwise be handled. This includes both data for which no handlers
                   1393: can be set (like some kinds of DTD declarations) and data which could
                   1394: be reported but which currently has no handler set.  The characters
                   1395: are passed exactly as they were present in the XML document except
                   1396: that they will be encoded in UTF-8 or UTF-16. Line boundaries are not
                   1397: normalized. Note that a byte order mark character is not passed to the
                   1398: default handler. There are no guarantees about how characters are
                   1399: divided between calls to the default handler: for example, a comment
                   1400: might be split between multiple calls.  Setting the handler with
                   1401: this call has the side effect of turning off expansion of references
                   1402: to internally defined general entities. Instead these references are
                   1403: passed to the default handler.</p>
                   1404:
                   1405: <p>See also <code><a
                   1406: href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p>
                   1407: </div>
                   1408:
                   1409: <div class="handler">
                   1410: <pre class="setter" id="XML_SetDefaultHandlerExpand">
                   1411: void XMLCALL
                   1412: XML_SetDefaultHandlerExpand(XML_Parser p,
                   1413:                             XML_DefaultHandler hndl)
                   1414: </pre>
                   1415: <pre class="signature">
                   1416: typedef void
                   1417: (XMLCALL *XML_DefaultHandler)(void *userData,
                   1418:                               const XML_Char *s,
                   1419:                               int len);
                   1420: </pre>
                   1421: <p>This sets a default handler, but doesn't inhibit the expansion of
                   1422: internal entity references.  The entity reference will not be passed
                   1423: to the default handler.</p>
                   1424:
                   1425: <p>See also <code><a
                   1426: href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p>
                   1427: </div>
                   1428:
                   1429: <div class="handler">
                   1430: <pre class="setter" id="XML_SetExternalEntityRefHandler">
                   1431: void XMLCALL
                   1432: XML_SetExternalEntityRefHandler(XML_Parser p,
                   1433:                                 XML_ExternalEntityRefHandler hndl)
                   1434: </pre>
                   1435: <pre class="signature">
                   1436: typedef int
                   1437: (XMLCALL *XML_ExternalEntityRefHandler)(XML_Parser p,
                   1438:                                         const XML_Char *context,
                   1439:                                         const XML_Char *base,
                   1440:                                         const XML_Char *systemId,
                   1441:                                         const XML_Char *publicId);
                   1442: </pre>
                   1443: <p>Set an external entity reference handler. This handler is also
                   1444: called for processing an external DTD subset if parameter entity parsing
                   1445: is in effect. (See <a href="#XML_SetParamEntityParsing">
                   1446: <code>XML_SetParamEntityParsing</code></a>.)</p>
                   1447:
                   1448: <p>The <code>context</code> parameter specifies the parsing context in
                   1449: the format expected by the <code>context</code> argument to <code><a
                   1450: href="#XML_ExternalEntityParserCreate"
                   1451: >XML_ExternalEntityParserCreate</a></code>.  <code>code</code> is
                   1452: valid only until the handler returns, so if the referenced entity is
                   1453: to be parsed later, it must be copied.  <code>context</code> is NULL
                   1454: only when the entity is a parameter entity, which is how one can
                   1455: differentiate between general and parameter entities.</p>
                   1456:
                   1457: <p>The <code>base</code> parameter is the base to use for relative
                   1458: system identifiers.  It is set by <code><a
                   1459: href="#XML_SetBase">XML_SetBase</a></code> and may be NULL. The
                   1460: <code>publicId</code> parameter is the public id given in the entity
                   1461: declaration and may be NULL.  <code>systemId</code> is the system
                   1462: identifier specified in the entity declaration and is never NULL.</p>
                   1463:
                   1464: <p>There are a couple of ways in which this handler differs from
                   1465: others.  First, this handler returns a status indicator (an
                   1466: integer). <code>XML_STATUS_OK</code> should be returned for successful
                   1467: handling of the external entity reference.  Returning
                   1468: <code>XML_STATUS_ERROR</code> indicates failure, and causes the
                   1469: calling parser to return an
                   1470: <code>XML_ERROR_EXTERNAL_ENTITY_HANDLING</code> error.</p>
                   1471:
                   1472: <p>Second, instead of having the user data as its first argument, it
                   1473: receives the parser that encountered the entity reference. This, along
                   1474: with the context parameter, may be used as arguments to a call to
                   1475: <code><a href= "#XML_ExternalEntityParserCreate"
                   1476: >XML_ExternalEntityParserCreate</a></code>.  Using the returned
                   1477: parser, the body of the external entity can be recursively parsed.</p>
                   1478:
                   1479: <p>Since this handler may be called recursively, it should not be saving
                   1480: information into global or static variables.</p>
                   1481: </div>
                   1482:
                   1483: <pre class="fcndec" id="XML_SetExternalEntityRefHandlerArg">
                   1484: void XMLCALL
                   1485: XML_SetExternalEntityRefHandlerArg(XML_Parser p,
                   1486:                                    void *arg)
                   1487: </pre>
                   1488: <div class="fcndef">
                   1489: <p>Set the argument passed to the ExternalEntityRefHandler.  If
                   1490: <code>arg</code> is not NULL, it is the new value passed to the
                   1491: handler set using <code><a href="#XML_SetExternalEntityRefHandler"
                   1492: >XML_SetExternalEntityRefHandler</a></code>; if <code>arg</code> is
                   1493: NULL, the argument passed to the handler function will be the parser
                   1494: object itself.</p>
                   1495:
                   1496: <p><strong>Note:</strong>
                   1497: The type of <code>arg</code> and the type of the first argument to the
                   1498: ExternalEntityRefHandler do not match.  This function takes a
                   1499: <code>void *</code> to be passed to the handler, while the handler
                   1500: accepts an <code>XML_Parser</code>.  This is a historical accident,
                   1501: but will not be corrected before Expat 2.0 (at the earliest) to avoid
                   1502: causing compiler warnings for code that's known to work with this
                   1503: API.  It is the responsibility of the application code to know the
                   1504: actual type of the argument passed to the handler and to manage it
                   1505: properly.</p>
                   1506: </div>
                   1507:
                   1508: <div class="handler">
                   1509: <pre class="setter" id="XML_SetSkippedEntityHandler">
                   1510: void XMLCALL
                   1511: XML_SetSkippedEntityHandler(XML_Parser p,
                   1512:                             XML_SkippedEntityHandler handler)
                   1513: </pre>
                   1514: <pre class="signature">
                   1515: typedef void
                   1516: (XMLCALL *XML_SkippedEntityHandler)(void *userData,
                   1517:                                     const XML_Char *entityName,
                   1518:                                     int is_parameter_entity);
                   1519: </pre>
                   1520: <p>Set a skipped entity handler. This is called in two situations:</p>
                   1521: <ol>
                   1522:    <li>An entity reference is encountered for which no declaration
                   1523:        has been read <em>and</em> this is not an error.</li>
                   1524:    <li>An internal entity reference is read, but not expanded, because
                   1525:        <a href="#XML_SetDefaultHandler"><code>XML_SetDefaultHandler</code></a>
                   1526:           has been called.</li>
                   1527: </ol>
                   1528: <p>The <code>is_parameter_entity</code> argument will be non-zero for
                   1529: a parameter entity and zero for a general entity.</p> <p>Note: skipped
                   1530: parameter entities in declarations and skipped general entities in
                   1531: attribute values cannot be reported, because the event would be out of
                   1532: sync with the reporting of the declarations or attribute values</p>
                   1533: </div>
                   1534:
                   1535: <div class="handler">
                   1536: <pre class="setter" id="XML_SetUnknownEncodingHandler">
                   1537: void XMLCALL
                   1538: XML_SetUnknownEncodingHandler(XML_Parser p,
                   1539:                               XML_UnknownEncodingHandler enchandler,
                   1540:                              void *encodingHandlerData)
                   1541: </pre>
                   1542: <pre class="signature">
                   1543: typedef int
                   1544: (XMLCALL *XML_UnknownEncodingHandler)(void *encodingHandlerData,
                   1545:                                       const XML_Char *name,
                   1546:                                       XML_Encoding *info);
                   1547:
                   1548: typedef struct {
                   1549:   int map[256];
                   1550:   void *data;
                   1551:   int (XMLCALL *convert)(void *data, const char *s);
                   1552:   void (XMLCALL *release)(void *data);
                   1553: } XML_Encoding;
                   1554: </pre>
                   1555: <p>Set a handler to deal with encodings other than the <a
                   1556: href="#builtin_encodings">built in set</a>. This should be done before
                   1557: <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a href=
                   1558: "#XML_ParseBuffer" >XML_ParseBuffer</a></code> have been called on the
                   1559: given parser.</p> <p>If the handler knows how to deal with an encoding
                   1560: with the given name, it should fill in the <code>info</code> data
                   1561: structure and return <code>XML_STATUS_OK</code>. Otherwise it
                   1562: should return <code>XML_STATUS_ERROR</code>. The handler will be called
                   1563: at most once per parsed (external) entity. The optional application
                   1564: data pointer <code>encodingHandlerData</code> will be passed back to
                   1565: the handler.</p>
                   1566:
                   1567: <p>The map array contains information for every possible possible leading
                   1568: byte in a byte sequence. If the corresponding value is &gt;= 0, then it's
                   1569: a single byte sequence and the byte encodes that Unicode value. If the
                   1570: value is -1, then that byte is invalid as the initial byte in a sequence.
                   1571: If the value is -n, where n is an integer &gt; 1, then n is the number of
                   1572: bytes in the sequence and the actual conversion is accomplished by a
                   1573: call to the function pointed at by convert. This function may return -1
                   1574: if the sequence itself is invalid. The convert pointer may be null if
                   1575: there are only single byte codes. The data parameter passed to the convert
                   1576: function is the data pointer from <code>XML_Encoding</code>. The
                   1577: string s is <em>NOT</em> nul-terminated and points at the sequence of
                   1578: bytes to be converted.</p>
                   1579:
                   1580: <p>The function pointed at by <code>release</code> is called by the
                   1581: parser when it is finished with the encoding. It may be NULL.</p>
                   1582: </div>
                   1583:
                   1584: <div class="handler">
                   1585: <pre class="setter" id="XML_SetStartNamespaceDeclHandler">
                   1586: void XMLCALL
                   1587: XML_SetStartNamespaceDeclHandler(XML_Parser p,
                   1588:                                 XML_StartNamespaceDeclHandler start);
                   1589: </pre>
                   1590: <pre class="signature">
                   1591: typedef void
                   1592: (XMLCALL *XML_StartNamespaceDeclHandler)(void *userData,
                   1593:                                          const XML_Char *prefix,
                   1594:                                          const XML_Char *uri);
                   1595: </pre>
                   1596: <p>Set a handler to be called when a namespace is declared. Namespace
                   1597: declarations occur inside start tags. But the namespace declaration start
                   1598: handler is called before the start tag handler for each namespace declared
                   1599: in that start tag.</p>
                   1600: </div>
                   1601:
                   1602: <div class="handler">
                   1603: <pre class="setter" id="XML_SetEndNamespaceDeclHandler">
                   1604: void XMLCALL
                   1605: XML_SetEndNamespaceDeclHandler(XML_Parser p,
                   1606:                               XML_EndNamespaceDeclHandler end);
                   1607: </pre>
                   1608: <pre class="signature">
                   1609: typedef void
                   1610: (XMLCALL *XML_EndNamespaceDeclHandler)(void *userData,
                   1611:                                        const XML_Char *prefix);
                   1612: </pre>
                   1613: <p>Set a handler to be called when leaving the scope of a namespace
                   1614: declaration. This will be called, for each namespace declaration,
                   1615: after the handler for the end tag of the element in which the
                   1616: namespace was declared.</p>
                   1617: </div>
                   1618:
                   1619: <div class="handler">
                   1620: <pre class="setter" id="XML_SetNamespaceDeclHandler">
                   1621: void XMLCALL
                   1622: XML_SetNamespaceDeclHandler(XML_Parser p,
                   1623:                             XML_StartNamespaceDeclHandler start,
                   1624:                             XML_EndNamespaceDeclHandler end)
                   1625: </pre>
                   1626: <p>Sets both namespace declaration handlers with a single call.</p>
                   1627: </div>
                   1628:
                   1629: <div class="handler">
                   1630: <pre class="setter" id="XML_SetXmlDeclHandler">
                   1631: void XMLCALL
                   1632: XML_SetXmlDeclHandler(XML_Parser p,
                   1633:                      XML_XmlDeclHandler xmldecl);
                   1634: </pre>
                   1635: <pre class="signature">
                   1636: typedef void
                   1637: (XMLCALL *XML_XmlDeclHandler)(void            *userData,
                   1638:                               const XML_Char  *version,
                   1639:                               const XML_Char  *encoding,
                   1640:                               int             standalone);
                   1641: </pre>
                   1642: <p>Sets a handler that is called for XML declarations and also for
                   1643: text declarations discovered in external entities. The way to
                   1644: distinguish is that the <code>version</code> parameter will be NULL
                   1645: for text declarations. The <code>encoding</code> parameter may be NULL
                   1646: for an XML declaration. The <code>standalone</code> argument will
                   1647: contain -1, 0, or 1 indicating respectively that there was no
                   1648: standalone parameter in the declaration, that it was given as no, or
                   1649: that it was given as yes.</p>
                   1650: </div>
                   1651:
                   1652: <div class="handler">
                   1653: <pre class="setter" id="XML_SetStartDoctypeDeclHandler">
                   1654: void XMLCALL
                   1655: XML_SetStartDoctypeDeclHandler(XML_Parser p,
                   1656:                               XML_StartDoctypeDeclHandler start);
                   1657: </pre>
                   1658: <pre class="signature">
                   1659: typedef void
                   1660: (XMLCALL *XML_StartDoctypeDeclHandler)(void           *userData,
                   1661:                                        const XML_Char *doctypeName,
                   1662:                                        const XML_Char *sysid,
                   1663:                                        const XML_Char *pubid,
                   1664:                                        int            has_internal_subset);
                   1665: </pre>
                   1666: <p>Set a handler that is called at the start of a DOCTYPE declaration,
                   1667: before any external or internal subset is parsed. Both <code>sysid</code>
                   1668: and <code>pubid</code> may be NULL. The <code>has_internal_subset</code>
                   1669: will be non-zero if the DOCTYPE declaration has an internal subset.</p>
                   1670: </div>
                   1671:
                   1672: <div class="handler">
                   1673: <pre class="setter" id="XML_SetEndDoctypeDeclHandler">
                   1674: void XMLCALL
                   1675: XML_SetEndDoctypeDeclHandler(XML_Parser p,
                   1676:                             XML_EndDoctypeDeclHandler end);
                   1677: </pre>
                   1678: <pre class="signature">
                   1679: typedef void
                   1680: (XMLCALL *XML_EndDoctypeDeclHandler)(void *userData);
                   1681: </pre>
                   1682: <p>Set a handler that is called at the end of a DOCTYPE declaration,
                   1683: after parsing any external subset.</p>
                   1684: </div>
                   1685:
                   1686: <div class="handler">
                   1687: <pre class="setter" id="XML_SetDoctypeDeclHandler">
                   1688: void XMLCALL
                   1689: XML_SetDoctypeDeclHandler(XML_Parser p,
                   1690:                          XML_StartDoctypeDeclHandler start,
                   1691:                          XML_EndDoctypeDeclHandler end);
                   1692: </pre>
                   1693: <p>Set both doctype handlers with one call.</p>
                   1694: </div>
                   1695:
                   1696: <div class="handler">
                   1697: <pre class="setter" id="XML_SetElementDeclHandler">
                   1698: void XMLCALL
                   1699: XML_SetElementDeclHandler(XML_Parser p,
                   1700:                          XML_ElementDeclHandler eldecl);
                   1701: </pre>
                   1702: <pre class="signature">
                   1703: typedef void
                   1704: (XMLCALL *XML_ElementDeclHandler)(void *userData,
                   1705:                                   const XML_Char *name,
                   1706:                                   XML_Content *model);
                   1707: </pre>
                   1708: <pre class="signature">
                   1709: enum XML_Content_Type {
                   1710:   XML_CTYPE_EMPTY = 1,
                   1711:   XML_CTYPE_ANY,
                   1712:   XML_CTYPE_MIXED,
                   1713:   XML_CTYPE_NAME,
                   1714:   XML_CTYPE_CHOICE,
                   1715:   XML_CTYPE_SEQ
                   1716: };
                   1717:
                   1718: enum XML_Content_Quant {
                   1719:   XML_CQUANT_NONE,
                   1720:   XML_CQUANT_OPT,
                   1721:   XML_CQUANT_REP,
                   1722:   XML_CQUANT_PLUS
                   1723: };
                   1724:
                   1725: typedef struct XML_cp XML_Content;
                   1726:
                   1727: struct XML_cp {
                   1728:   enum XML_Content_Type                type;
                   1729:   enum XML_Content_Quant       quant;
                   1730:   const XML_Char *             name;
                   1731:   unsigned int                 numchildren;
                   1732:   XML_Content *                        children;
                   1733: };
                   1734: </pre>
                   1735: <p>Sets a handler for element declarations in a DTD. The handler gets
                   1736: called with the name of the element in the declaration and a pointer
                   1737: to a structure that contains the element model. It is the
                   1738: application's responsibility to free this data structure using
                   1739: <code><a href="#XML_FreeContentModel"
                   1740: >XML_FreeContentModel</a></code>.</p>
                   1741:
                   1742: <p>The <code>model</code> argument is the root of a tree of
                   1743: <code>XML_Content</code> nodes. If <code>type</code> equals
                   1744: <code>XML_CTYPE_EMPTY</code> or <code>XML_CTYPE_ANY</code>, then
                   1745: <code>quant</code> will be <code>XML_CQUANT_NONE</code>, and the other
                   1746: fields will be zero or NULL.  If <code>type</code> is
                   1747: <code>XML_CTYPE_MIXED</code>, then <code>quant</code> will be
                   1748: <code>XML_CQUANT_NONE</code> or <code>XML_CQUANT_REP</code> and
                   1749: <code>numchildren</code> will contain the number of elements that are
                   1750: allowed to be mixed in and <code>children</code> points to an array of
                   1751: <code>XML_Content</code> structures that will all have type
                   1752: XML_CTYPE_NAME with no quantification.  Only the root node can be type
                   1753: <code>XML_CTYPE_EMPTY</code>, <code>XML_CTYPE_ANY</code>, or
                   1754: <code>XML_CTYPE_MIXED</code>.</p>
                   1755:
                   1756: <p>For type <code>XML_CTYPE_NAME</code>, the <code>name</code> field
                   1757: points to the name and the <code>numchildren</code> and
                   1758: <code>children</code> fields will be zero and NULL. The
                   1759: <code>quant</code> field will indicate any quantifiers placed on the
                   1760: name.</p>
                   1761:
                   1762: <p>Types <code>XML_CTYPE_CHOICE</code> and <code>XML_CTYPE_SEQ</code>
                   1763: indicate a choice or sequence respectively. The
                   1764: <code>numchildren</code> field indicates how many nodes in the choice
                   1765: or sequence and <code>children</code> points to the nodes.</p>
                   1766: </div>
                   1767:
                   1768: <div class="handler">
                   1769: <pre class="setter" id="XML_SetAttlistDeclHandler">
                   1770: void XMLCALL
                   1771: XML_SetAttlistDeclHandler(XML_Parser p,
                   1772:                           XML_AttlistDeclHandler attdecl);
                   1773: </pre>
                   1774: <pre class="signature">
                   1775: typedef void
                   1776: (XMLCALL *XML_AttlistDeclHandler)(void           *userData,
                   1777:                                   const XML_Char *elname,
                   1778:                                   const XML_Char *attname,
                   1779:                                   const XML_Char *att_type,
                   1780:                                   const XML_Char *dflt,
                   1781:                                   int            isrequired);
                   1782: </pre>
                   1783: <p>Set a handler for attlist declarations in the DTD. This handler is
                   1784: called for <em>each</em> attribute. So a single attlist declaration
                   1785: with multiple attributes declared will generate multiple calls to this
                   1786: handler. The <code>elname</code> parameter returns the name of the
                   1787: element for which the attribute is being declared. The attribute name
                   1788: is in the <code>attname</code> parameter. The attribute type is in the
                   1789: <code>att_type</code> parameter.  It is the string representing the
                   1790: type in the declaration with whitespace removed.</p>
                   1791:
                   1792: <p>The <code>dflt</code> parameter holds the default value. It will be
                   1793: NULL in the case of "#IMPLIED" or "#REQUIRED" attributes. You can
                   1794: distinguish these two cases by checking the <code>isrequired</code>
                   1795: parameter, which will be true in the case of "#REQUIRED" attributes.
                   1796: Attributes which are "#FIXED" will have also have a true
                   1797: <code>isrequired</code>, but they will have the non-NULL fixed value
                   1798: in the <code>dflt</code> parameter.</p>
                   1799: </div>
                   1800:
                   1801: <div class="handler">
                   1802: <pre class="setter" id="XML_SetEntityDeclHandler">
                   1803: void XMLCALL
                   1804: XML_SetEntityDeclHandler(XML_Parser p,
                   1805:                         XML_EntityDeclHandler handler);
                   1806: </pre>
                   1807: <pre class="signature">
                   1808: typedef void
                   1809: (XMLCALL *XML_EntityDeclHandler)(void           *userData,
                   1810:                                  const XML_Char *entityName,
                   1811:                                  int            is_parameter_entity,
                   1812:                                  const XML_Char *value,
                   1813:                                  int            value_length,
                   1814:                                  const XML_Char *base,
                   1815:                                  const XML_Char *systemId,
                   1816:                                  const XML_Char *publicId,
                   1817:                                  const XML_Char *notationName);
                   1818: </pre>
                   1819: <p>Sets a handler that will be called for all entity declarations.
                   1820: The <code>is_parameter_entity</code> argument will be non-zero in the
                   1821: case of parameter entities and zero otherwise.</p>
                   1822:
                   1823: <p>For internal entities (<code>&lt;!ENTITY foo "bar"&gt;</code>),
                   1824: <code>value</code> will be non-NULL and <code>systemId</code>,
                   1825: <code>publicId</code>, and <code>notationName</code> will all be NULL.
                   1826: The value string is <em>not</em> NULL terminated; the length is
                   1827: provided in the <code>value_length</code> parameter. Do not use
                   1828: <code>value_length</code> to test for internal entities, since it is
                   1829: legal to have zero-length values. Instead check for whether or not
                   1830: <code>value</code> is NULL.</p> <p>The <code>notationName</code>
                   1831: argument will have a non-NULL value only for unparsed entity
                   1832: declarations.</p>
                   1833: </div>
                   1834:
                   1835: <div class="handler">
                   1836: <pre class="setter" id="XML_SetUnparsedEntityDeclHandler">
                   1837: void XMLCALL
                   1838: XML_SetUnparsedEntityDeclHandler(XML_Parser p,
                   1839:                                  XML_UnparsedEntityDeclHandler h)
                   1840: </pre>
                   1841: <pre class="signature">
                   1842: typedef void
                   1843: (XMLCALL *XML_UnparsedEntityDeclHandler)(void *userData,
                   1844:                                          const XML_Char *entityName,
                   1845:                                          const XML_Char *base,
                   1846:                                          const XML_Char *systemId,
                   1847:                                          const XML_Char *publicId,
                   1848:                                          const XML_Char *notationName);
                   1849: </pre>
                   1850: <p>Set a handler that receives declarations of unparsed entities. These
                   1851: are entity declarations that have a notation (NDATA) field:</p>
                   1852:
                   1853: <div id="eg"><pre>
                   1854: &lt;!ENTITY logo SYSTEM "images/logo.gif" NDATA gif&gt;
                   1855: </pre></div>
                   1856: <p>This handler is obsolete and is provided for backwards
                   1857: compatibility.  Use instead <a href= "#XML_SetEntityDeclHandler"
                   1858: >XML_SetEntityDeclHandler</a>.</p>
                   1859: </div>
                   1860:
                   1861: <div class="handler">
                   1862: <pre class="setter" id="XML_SetNotationDeclHandler">
                   1863: void XMLCALL
                   1864: XML_SetNotationDeclHandler(XML_Parser p,
                   1865:                            XML_NotationDeclHandler h)
                   1866: </pre>
                   1867: <pre class="signature">
                   1868: typedef void
                   1869: (XMLCALL *XML_NotationDeclHandler)(void *userData,
                   1870:                                    const XML_Char *notationName,
                   1871:                                    const XML_Char *base,
                   1872:                                    const XML_Char *systemId,
                   1873:                                    const XML_Char *publicId);
                   1874: </pre>
                   1875: <p>Set a handler that receives notation declarations.</p>
                   1876: </div>
                   1877:
                   1878: <div class="handler">
                   1879: <pre class="setter" id="XML_SetNotStandaloneHandler">
                   1880: void XMLCALL
                   1881: XML_SetNotStandaloneHandler(XML_Parser p,
                   1882:                             XML_NotStandaloneHandler h)
                   1883: </pre>
                   1884: <pre class="signature">
                   1885: typedef int
                   1886: (XMLCALL *XML_NotStandaloneHandler)(void *userData);
                   1887: </pre>
                   1888: <p>Set a handler that is called if the document is not "standalone".
                   1889: This happens when there is an external subset or a reference to a
                   1890: parameter entity, but does not have standalone set to "yes" in an XML
                   1891: declaration.  If this handler returns <code>XML_STATUS_ERROR</code>,
                   1892: then the parser will throw an <code>XML_ERROR_NOT_STANDALONE</code>
                   1893: error.</p>
                   1894: </div>
                   1895:
                   1896: <h3><a name="position">Parse position and error reporting functions</a></h3>
                   1897:
                   1898: <p>These are the functions you'll want to call when the parse
                   1899: functions return <code>XML_STATUS_ERROR</code> (a parse error has
                   1900: occurred), although the position reporting functions are useful outside
                   1901: of errors. The position reported is the byte position (in the original
                   1902: document or entity encoding) of the first of the sequence of
                   1903: characters that generated the current event (or the error that caused
                   1904: the parse functions to return <code>XML_STATUS_ERROR</code>.)  The
                   1905: exceptions are callbacks trigged by declarations in the document
                   1906: prologue, in which case they exact position reported is somewhere in the
                   1907: relevant markup, but not necessarily as meaningful as for other
                   1908: events.</p>
                   1909:
                   1910: <p>The position reporting functions are accurate only outside of the
                   1911: DTD.  In other words, they usually return bogus information when
                   1912: called from within a DTD declaration handler.</p>
                   1913:
                   1914: <pre class="fcndec" id="XML_GetErrorCode">
                   1915: enum XML_Error XMLCALL
                   1916: XML_GetErrorCode(XML_Parser p);
                   1917: </pre>
                   1918: <div class="fcndef">
                   1919: Return what type of error has occurred.
                   1920: </div>
                   1921:
                   1922: <pre class="fcndec" id="XML_ErrorString">
                   1923: const XML_LChar * XMLCALL
                   1924: XML_ErrorString(enum XML_Error code);
                   1925: </pre>
                   1926: <div class="fcndef">
                   1927: Return a string describing the error corresponding to code.
                   1928: The code should be one of the enums that can be returned from
                   1929: <code><a href= "#XML_GetErrorCode" >XML_GetErrorCode</a></code>.
                   1930: </div>
                   1931:
                   1932: <pre class="fcndec" id="XML_GetCurrentByteIndex">
                   1933: XML_Index XMLCALL
                   1934: XML_GetCurrentByteIndex(XML_Parser p);
                   1935: </pre>
                   1936: <div class="fcndef">
                   1937: Return the byte offset of the position.  This always corresponds to
                   1938: the values returned by <code><a href= "#XML_GetCurrentLineNumber"
                   1939: >XML_GetCurrentLineNumber</a></code> and <code><a href=
                   1940: "#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>.
                   1941: </div>
                   1942:
                   1943: <pre class="fcndec" id="XML_GetCurrentLineNumber">
                   1944: XML_Size XMLCALL
                   1945: XML_GetCurrentLineNumber(XML_Parser p);
                   1946: </pre>
                   1947: <div class="fcndef">
                   1948: Return the line number of the position.  The first line is reported as
                   1949: <code>1</code>.
                   1950: </div>
                   1951:
                   1952: <pre class="fcndec" id="XML_GetCurrentColumnNumber">
                   1953: XML_Size XMLCALL
                   1954: XML_GetCurrentColumnNumber(XML_Parser p);
                   1955: </pre>
                   1956: <div class="fcndef">
                   1957: Return the offset, from the beginning of the current line, of
                   1958: the position.
                   1959: </div>
                   1960:
                   1961: <pre class="fcndec" id="XML_GetCurrentByteCount">
                   1962: int XMLCALL
                   1963: XML_GetCurrentByteCount(XML_Parser p);
                   1964: </pre>
                   1965: <div class="fcndef">
                   1966: Return the number of bytes in the current event. Returns
                   1967: <code>0</code> if the event is inside a reference to an internal
                   1968: entity and for the end-tag event for empty element tags (the later can
                   1969: be used to distinguish empty-element tags from empty elements using
                   1970: separate start and end tags).
                   1971: </div>
                   1972:
                   1973: <pre class="fcndec" id="XML_GetInputContext">
                   1974: const char * XMLCALL
                   1975: XML_GetInputContext(XML_Parser p,
                   1976:                     int *offset,
                   1977:                     int *size);
                   1978: </pre>
                   1979: <div class="fcndef">
                   1980:
                   1981: <p>Returns the parser's input buffer, sets the integer pointed at by
                   1982: <code>offset</code> to the offset within this buffer of the current
                   1983: parse position, and set the integer pointed at by <code>size</code> to
                   1984: the size of the returned buffer.</p>
                   1985:
                   1986: <p>This should only be called from within a handler during an active
                   1987: parse and the returned buffer should only be referred to from within
                   1988: the handler that made the call. This input buffer contains the
                   1989: untranslated bytes of the input.</p>
                   1990:
                   1991: <p>Only a limited amount of context is kept, so if the event
                   1992: triggering a call spans over a very large amount of input, the actual
                   1993: parse position may be before the beginning of the buffer.</p>
                   1994:
                   1995: <p>If <code>XML_CONTEXT_BYTES</code> is not defined, this will always
                   1996: return NULL.</p>
                   1997: </div>
                   1998:
                   1999: <h3><a name="miscellaneous">Miscellaneous functions</a></h3>
                   2000:
                   2001: <p>The functions in this section either obtain state information from
                   2002: the parser or can be used to dynamicly set parser options.</p>
                   2003:
                   2004: <pre class="fcndec" id="XML_SetUserData">
                   2005: void XMLCALL
                   2006: XML_SetUserData(XML_Parser p,
                   2007:                 void *userData);
                   2008: </pre>
                   2009: <div class="fcndef">
                   2010: This sets the user data pointer that gets passed to handlers.  It
                   2011: overwrites any previous value for this pointer. Note that the
                   2012: application is responsible for freeing the memory associated with
                   2013: <code>userData</code> when it is finished with the parser. So if you
                   2014: call this when there's already a pointer there, and you haven't freed
                   2015: the memory associated with it, then you've probably just leaked
                   2016: memory.
                   2017: </div>
                   2018:
                   2019: <pre class="fcndec" id="XML_GetUserData">
                   2020: void * XMLCALL
                   2021: XML_GetUserData(XML_Parser p);
                   2022: </pre>
                   2023: <div class="fcndef">
                   2024: This returns the user data pointer that gets passed to handlers.
                   2025: It is actually implemented as a macro.
                   2026: </div>
                   2027:
                   2028: <pre class="fcndec" id="XML_UseParserAsHandlerArg">
                   2029: void XMLCALL
                   2030: XML_UseParserAsHandlerArg(XML_Parser p);
                   2031: </pre>
                   2032: <div class="fcndef">
                   2033: After this is called, handlers receive the parser in their
                   2034: <code>userData</code> arguments.  The user data can still be obtained
                   2035: using the <code><a href= "#XML_GetUserData"
                   2036: >XML_GetUserData</a></code> function.
                   2037: </div>
                   2038:
                   2039: <pre class="fcndec" id="XML_SetBase">
                   2040: enum XML_Status XMLCALL
                   2041: XML_SetBase(XML_Parser p,
                   2042:             const XML_Char *base);
                   2043: </pre>
                   2044: <div class="fcndef">
                   2045: Set the base to be used for resolving relative URIs in system
                   2046: identifiers.  The return value is <code>XML_STATUS_ERROR</code> if
                   2047: there's no memory to store base, otherwise it's
                   2048: <code>XML_STATUS_OK</code>.
                   2049: </div>
                   2050:
                   2051: <pre class="fcndec" id="XML_GetBase">
                   2052: const XML_Char * XMLCALL
                   2053: XML_GetBase(XML_Parser p);
                   2054: </pre>
                   2055: <div class="fcndef">
                   2056: Return the base for resolving relative URIs.
                   2057: </div>
                   2058:
                   2059: <pre class="fcndec" id="XML_GetSpecifiedAttributeCount">
                   2060: int XMLCALL
                   2061: XML_GetSpecifiedAttributeCount(XML_Parser p);
                   2062: </pre>
                   2063: <div class="fcndef">
                   2064: When attributes are reported to the start handler in the atts vector,
                   2065: attributes that were explicitly set in the element occur before any
                   2066: attributes that receive their value from default information in an
                   2067: ATTLIST declaration. This function returns the number of attributes
                   2068: that were explicitly set times two, thus giving the offset in the
                   2069: <code>atts</code> array passed to the start tag handler of the first
                   2070: attribute set due to defaults. It supplies information for the last
                   2071: call to a start handler. If called inside a start handler, then that
                   2072: means the current call.
                   2073: </div>
                   2074:
                   2075: <pre class="fcndec" id="XML_GetIdAttributeIndex">
                   2076: int XMLCALL
                   2077: XML_GetIdAttributeIndex(XML_Parser p);
                   2078: </pre>
                   2079: <div class="fcndef">
                   2080: Returns the index of the ID attribute passed in the atts array in the
                   2081: last call to <code><a href= "#XML_StartElementHandler"
                   2082: >XML_StartElementHandler</a></code>, or -1 if there is no ID
                   2083: attribute. If called inside a start handler, then that means the
                   2084: current call.
                   2085: </div>
                   2086:
1.1.1.2 ! spz      2087: <pre class="fcndec" id="XML_GetAttributeInfo">
        !          2088: const XML_AttrInfo * XMLCALL
        !          2089: XML_GetAttributeInfo(XML_Parser parser);
        !          2090: </pre>
        !          2091: <pre class="signature">
        !          2092: typedef struct {
        !          2093:   XML_Index  nameStart;  /* Offset to beginning of the attribute name. */
        !          2094:   XML_Index  nameEnd;    /* Offset after the attribute name's last byte. */
        !          2095:   XML_Index  valueStart; /* Offset to beginning of the attribute value. */
        !          2096:   XML_Index  valueEnd;   /* Offset after the attribute value's last byte. */
        !          2097: } XML_AttrInfo;
        !          2098: </pre>
        !          2099: <div class="fcndef">
        !          2100: Returns an array of <code>XML_AttrInfo</code> structures for the
        !          2101: attribute/value pairs passed in the last call to the
        !          2102: <code>XML_StartElementHandler</code> that were specified
        !          2103: in the start-tag rather than defaulted. Each attribute/value pair counts
        !          2104: as 1; thus the number of entries in the array is
        !          2105: <code>XML_GetSpecifiedAttributeCount(parser) / 2</code>.
        !          2106: </div>
        !          2107:
1.1       tron     2108: <pre class="fcndec" id="XML_SetEncoding">
                   2109: enum XML_Status XMLCALL
                   2110: XML_SetEncoding(XML_Parser p,
                   2111:                 const XML_Char *encoding);
                   2112: </pre>
                   2113: <div class="fcndef">
                   2114: Set the encoding to be used by the parser. It is equivalent to
                   2115: passing a non-null encoding argument to the parser creation functions.
                   2116: It must not be called after <code><a href= "#XML_Parse"
                   2117: >XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer"
                   2118: >XML_ParseBuffer</a></code> have been called on the given parser.
                   2119: Returns <code>XML_STATUS_OK</code> on success or
                   2120: <code>XML_STATUS_ERROR</code> on error.
                   2121: </div>
                   2122:
                   2123: <pre class="fcndec" id="XML_SetParamEntityParsing">
                   2124: int XMLCALL
                   2125: XML_SetParamEntityParsing(XML_Parser p,
                   2126:                           enum XML_ParamEntityParsing code);
                   2127: </pre>
                   2128: <div class="fcndef">
                   2129: This enables parsing of parameter entities, including the external
                   2130: parameter entity that is the external DTD subset, according to
                   2131: <code>code</code>.
                   2132: The choices for <code>code</code> are:
                   2133: <ul>
                   2134: <li><code>XML_PARAM_ENTITY_PARSING_NEVER</code></li>
                   2135: <li><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></li>
                   2136: <li><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></li>
                   2137: </ul>
1.1.1.2 ! spz      2138: <b>Note:</b> If <code>XML_SetParamEntityParsing</code> is called after
        !          2139: <code>XML_Parse</code> or <code>XML_ParseBuffer</code>, then it has
        !          2140: no effect and will always return 0.
        !          2141: </div>
        !          2142:
        !          2143: <pre class="fcndec" id="XML_SetHashSalt">
        !          2144: int XMLCALL
        !          2145: XML_SetHashSalt(XML_Parser p,
        !          2146:                 unsigned long hash_salt);
        !          2147: </pre>
        !          2148: <div class="fcndef">
        !          2149: Sets the hash salt to use for internal hash calculations.
        !          2150: Helps in preventing DoS attacks based on predicting hash
        !          2151: function behavior. In order to have an effect this must be called
        !          2152: before parsing has started. Returns 1 if successful, 0 when called
        !          2153: after <code>XML_Parse</code> or <code>XML_ParseBuffer</code>.
        !          2154: <p><b>Note:</b> This call is optional, as the parser will auto-generate a new
        !          2155: random salt value if no value has been set at the start of parsing.</p>
1.1       tron     2156: </div>
                   2157:
                   2158: <pre class="fcndec" id="XML_UseForeignDTD">
                   2159: enum XML_Error XMLCALL
                   2160: XML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD);
                   2161: </pre>
                   2162: <div class="fcndef">
                   2163: <p>This function allows an application to provide an external subset
                   2164: for the document type declaration for documents which do not specify
                   2165: an external subset of their own.  For documents which specify an
                   2166: external subset in their DOCTYPE declaration, the application-provided
                   2167: subset will be ignored.  If the document does not contain a DOCTYPE
                   2168: declaration at all and <code>useDTD</code> is true, the
                   2169: application-provided subset will be parsed, but the
                   2170: <code>startDoctypeDeclHandler</code> and
                   2171: <code>endDoctypeDeclHandler</code> functions, if set, will not be
                   2172: called.  The setting of parameter entity parsing, controlled using
                   2173: <code><a href= "#XML_SetParamEntityParsing"
                   2174: >XML_SetParamEntityParsing</a></code>, will be honored.</p>
                   2175:
                   2176: <p>The application-provided external subset is read by calling the
                   2177: external entity reference handler set via <code><a href=
                   2178: "#XML_SetExternalEntityRefHandler"
                   2179: >XML_SetExternalEntityRefHandler</a></code> with both
                   2180: <code>publicId</code> and <code>systemId</code> set to NULL.</p>
                   2181:
                   2182: <p>If this function is called after parsing has begun, it returns
                   2183: <code>XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING</code> and ignores
                   2184: <code>useDTD</code>.  If called when Expat has been compiled without
                   2185: DTD support, it returns
                   2186: <code>XML_ERROR_FEATURE_REQUIRES_XML_DTD</code>.  Otherwise, it
                   2187: returns <code>XML_ERROR_NONE</code>.</p>
                   2188:
                   2189: <p><b>Note:</b> For the purpose of checking WFC: Entity Declared, passing
                   2190: <code>useDTD == XML_TRUE</code> will make the parser behave as if
                   2191: the document had a DTD with an external subset. This holds true even if
                   2192: the external entity reference handler returns without action.</p>
                   2193: </div>
                   2194:
                   2195: <pre class="fcndec" id="XML_SetReturnNSTriplet">
                   2196: void XMLCALL
                   2197: XML_SetReturnNSTriplet(XML_Parser parser,
                   2198:                        int        do_nst);
                   2199: </pre>
                   2200: <div class="fcndef">
                   2201: <p>
                   2202: This function only has an effect when using a parser created with
                   2203: <code><a href= "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>,
                   2204: i.e. when namespace processing is in effect. The <code>do_nst</code>
                   2205: sets whether or not prefixes are returned with names qualified with a
                   2206: namespace prefix. If this function is called with <code>do_nst</code>
                   2207: non-zero, then afterwards namespace qualified names (that is qualified
                   2208: with a prefix as opposed to belonging to a default namespace) are
                   2209: returned as a triplet with the three parts separated by the namespace
                   2210: separator specified when the parser was created.  The order of
                   2211: returned parts is URI, local name, and prefix.</p> <p>If
                   2212: <code>do_nst</code> is zero, then namespaces are reported in the
                   2213: default manner, URI then local_name separated by the namespace
                   2214: separator.</p>
                   2215: </div>
                   2216:
                   2217: <pre class="fcndec" id="XML_DefaultCurrent">
                   2218: void XMLCALL
                   2219: XML_DefaultCurrent(XML_Parser parser);
                   2220: </pre>
                   2221: <div class="fcndef">
                   2222: This can be called within a handler for a start element, end element,
                   2223: processing instruction or character data.  It causes the corresponding
                   2224: markup to be passed to the default handler set by <code><a
                   2225: href="#XML_SetDefaultHandler" >XML_SetDefaultHandler</a></code> or
                   2226: <code><a href="#XML_SetDefaultHandlerExpand"
                   2227: >XML_SetDefaultHandlerExpand</a></code>.  It does nothing if there is
                   2228: not a default handler.
                   2229: </div>
                   2230:
                   2231: <pre class="fcndec" id="XML_ExpatVersion">
                   2232: XML_LChar * XMLCALL
                   2233: XML_ExpatVersion();
                   2234: </pre>
                   2235: <div class="fcndef">
                   2236: Return the library version as a string (e.g. <code>"expat_1.95.1"</code>).
                   2237: </div>
                   2238:
                   2239: <pre class="fcndec" id="XML_ExpatVersionInfo">
                   2240: struct XML_Expat_Version XMLCALL
                   2241: XML_ExpatVersionInfo();
                   2242: </pre>
                   2243: <pre class="signature">
                   2244: typedef struct {
                   2245:   int major;
                   2246:   int minor;
                   2247:   int micro;
                   2248: } XML_Expat_Version;
                   2249: </pre>
                   2250: <div class="fcndef">
                   2251: Return the library version information as a structure.
                   2252: Some macros are also defined that support compile-time tests of the
                   2253: library version:
                   2254: <ul>
                   2255: <li><code>XML_MAJOR_VERSION</code></li>
                   2256: <li><code>XML_MINOR_VERSION</code></li>
                   2257: <li><code>XML_MICRO_VERSION</code></li>
                   2258: </ul>
                   2259: Testing these constants is currently the best way to determine if
                   2260: particular parts of the Expat API are available.
                   2261: </div>
                   2262:
                   2263: <pre class="fcndec" id="XML_GetFeatureList">
                   2264: const XML_Feature * XMLCALL
                   2265: XML_GetFeatureList();
                   2266: </pre>
                   2267: <pre class="signature">
                   2268: enum XML_FeatureEnum {
                   2269:   XML_FEATURE_END = 0,
                   2270:   XML_FEATURE_UNICODE,
                   2271:   XML_FEATURE_UNICODE_WCHAR_T,
                   2272:   XML_FEATURE_DTD,
                   2273:   XML_FEATURE_CONTEXT_BYTES,
                   2274:   XML_FEATURE_MIN_SIZE,
                   2275:   XML_FEATURE_SIZEOF_XML_CHAR,
                   2276:   XML_FEATURE_SIZEOF_XML_LCHAR,
                   2277:   XML_FEATURE_NS,
                   2278:   XML_FEATURE_LARGE_SIZE
                   2279: };
                   2280:
                   2281: typedef struct {
                   2282:   enum XML_FeatureEnum  feature;
                   2283:   XML_LChar            *name;
                   2284:   long int              value;
                   2285: } XML_Feature;
                   2286: </pre>
                   2287: <div class="fcndef">
                   2288: <p>Returns a list of "feature" records, providing details on how
                   2289: Expat was configured at compile time.  Most applications should not
                   2290: need to worry about this, but this information is otherwise not
                   2291: available from Expat.  This function allows code that does need to
                   2292: check these features to do so at runtime.</p>
                   2293:
                   2294: <p>The return value is an array of <code>XML_Feature</code>,
                   2295: terminated by a record with a <code>feature</code> of
                   2296: <code>XML_FEATURE_END</code> and <code>name</code> of NULL,
                   2297: identifying the feature-test macros Expat was compiled with.  Since an
                   2298: application that requires this kind of information needs to determine
                   2299: the type of character the <code>name</code> points to, records for the
                   2300: <code>XML_FEATURE_SIZEOF_XML_CHAR</code> and
                   2301: <code>XML_FEATURE_SIZEOF_XML_LCHAR</code> will be located at the
                   2302: beginning of the list, followed by <code>XML_FEATURE_UNICODE</code>
                   2303: and <code>XML_FEATURE_UNICODE_WCHAR_T</code>, if they are present at
                   2304: all.</p>
                   2305:
                   2306: <p>Some features have an associated value.  If there isn't an
                   2307: associated value, the <code>value</code> field is set to 0.  At this
                   2308: time, the following features have been defined to have values:</p>
                   2309:
                   2310: <dl>
                   2311:   <dt><code>XML_FEATURE_SIZEOF_XML_CHAR</code></dt>
                   2312:   <dd>The number of bytes occupied by one <code>XML_Char</code>
                   2313:   character.</dd>
                   2314:   <dt><code>XML_FEATURE_SIZEOF_XML_LCHAR</code></dt>
                   2315:   <dd>The number of bytes occupied by one <code>XML_LChar</code>
                   2316:   character.</dd>
                   2317:   <dt><code>XML_FEATURE_CONTEXT_BYTES</code></dt>
                   2318:   <dd>The maximum number of characters of context which can be
                   2319:   reported by <code><a href= "#XML_GetInputContext"
                   2320:   >XML_GetInputContext</a></code>.</dd>
                   2321: </dl>
                   2322: </div>
                   2323:
                   2324: <pre class="fcndec" id="XML_FreeContentModel">
                   2325: void XMLCALL
                   2326: XML_FreeContentModel(XML_Parser parser, XML_Content *model);
                   2327: </pre>
                   2328: <div class="fcndef">
                   2329: Function to deallocate the <code>model</code> argument passed to the
                   2330: <code>XML_ElementDeclHandler</code> callback set using <code><a
                   2331: href="#XML_SetElementDeclHandler" >XML_ElementDeclHandler</a></code>.
                   2332: This function should not be used for any other purpose.
                   2333: </div>
                   2334:
                   2335: <p>The following functions allow external code to share the memory
                   2336: allocator an <code>XML_Parser</code> has been configured to use.  This
                   2337: is especially useful for third-party libraries that interact with a
                   2338: parser object created by application code, or heavily layered
                   2339: applications.  This can be essential when using dynamically loaded
                   2340: libraries which use different C standard libraries (this can happen on
                   2341: Windows, at least).</p>
                   2342:
                   2343: <pre class="fcndec" id="XML_MemMalloc">
                   2344: void * XMLCALL
                   2345: XML_MemMalloc(XML_Parser parser, size_t size);
                   2346: </pre>
                   2347: <div class="fcndef">
                   2348: Allocate <code>size</code> bytes of memory using the allocator the
                   2349: <code>parser</code> object has been configured to use.  Returns a
                   2350: pointer to the memory or NULL on failure.  Memory allocated in this
                   2351: way must be freed using <code><a href="#XML_MemFree"
                   2352: >XML_MemFree</a></code>.
                   2353: </div>
                   2354:
                   2355: <pre class="fcndec" id="XML_MemRealloc">
                   2356: void * XMLCALL
                   2357: XML_MemRealloc(XML_Parser parser, void *ptr, size_t size);
                   2358: </pre>
                   2359: <div class="fcndef">
                   2360: Allocate <code>size</code> bytes of memory using the allocator the
                   2361: <code>parser</code> object has been configured to use.
                   2362: <code>ptr</code> must point to a block of memory allocated by <code><a
                   2363: href="#XML_MemMalloc" >XML_MemMalloc</a></code> or
                   2364: <code>XML_MemRealloc</code>, or be NULL.  This function tries to
                   2365: expand the block pointed to by <code>ptr</code> if possible.  Returns
                   2366: a pointer to the memory or NULL on failure.  On success, the original
                   2367: block has either been expanded or freed.  On failure, the original
                   2368: block has not been freed; the caller is responsible for freeing the
                   2369: original block.  Memory allocated in this way must be freed using
                   2370: <code><a href="#XML_MemFree"
                   2371: >XML_MemFree</a></code>.
                   2372: </div>
                   2373:
                   2374: <pre class="fcndec" id="XML_MemFree">
                   2375: void XMLCALL
                   2376: XML_MemFree(XML_Parser parser, void *ptr);
                   2377: </pre>
                   2378: <div class="fcndef">
                   2379: Free a block of memory pointed to by <code>ptr</code>.  The block must
                   2380: have been allocated by <code><a href="#XML_MemMalloc"
                   2381: >XML_MemMalloc</a></code> or <code>XML_MemRealloc</code>, or be NULL.
                   2382: </div>
                   2383:
                   2384: <hr />
                   2385: <p><a href="http://validator.w3.org/check/referer"><img
                   2386:         src="valid-xhtml10.png" alt="Valid XHTML 1.0!"
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                   2388: </div>
                   2389: </body>
                   2390: </html>

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