forked from KolibriOS/kolibrios
2391 lines
93 KiB
HTML
2391 lines
93 KiB
HTML
<?xml version="1.0" encoding="iso-8859-1"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<html>
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<head>
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<!-- Copyright 1999,2000 Clark Cooper <coopercc@netheaven.com>
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All rights reserved.
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This is free software. You may distribute or modify according to
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the terms of the MIT/X License -->
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<title>Expat XML Parser</title>
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<meta name="author" content="Clark Cooper, coopercc@netheaven.com" />
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<meta http-equiv="Content-Style-Type" content="text/css" />
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<link href="style.css" rel="stylesheet" type="text/css" />
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</head>
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<body>
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<table cellspacing="0" cellpadding="0" width="100%">
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<tr>
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<td class="corner"><img src="expat.png" alt="(Expat logo)" /></td>
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<td class="banner"><h1>The Expat XML Parser</h1></td>
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</tr>
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<tr>
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<td class="releaseno">Release 2.0.1</td>
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<td></td>
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</tr>
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</table>
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<div class="content">
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<p>Expat is a library, written in C, for parsing XML documents. It's
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the underlying XML parser for the open source Mozilla project, Perl's
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<code>XML::Parser</code>, Python's <code>xml.parsers.expat</code>, and
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other open-source XML parsers.</p>
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<p>This library is the creation of James Clark, who's also given us
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groff (an nroff look-alike), Jade (an implemention of ISO's DSSSL
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stylesheet language for SGML), XP (a Java XML parser package), XT (a
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Java XSL engine). James was also the technical lead on the XML
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Working Group at W3C that produced the XML specification.</p>
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<p>This is free software, licensed under the <a
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href="../COPYING">MIT/X Consortium license</a>. You may download it
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from <a href="http://www.libexpat.org/">the Expat home page</a>.
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</p>
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<p>The bulk of this document was originally commissioned as an article
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by <a href="http://www.xml.com/">XML.com</a>. They graciously allowed
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Clark Cooper to retain copyright and to distribute it with Expat.
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This version has been substantially extended to include documentation
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on features which have been added since the original article was
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published, and additional information on using the original
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interface.</p>
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<hr />
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<h2>Table of Contents</h2>
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<ul>
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<li><a href="#overview">Overview</a></li>
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<li><a href="#building">Building and Installing</a></li>
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<li><a href="#using">Using Expat</a></li>
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<li><a href="#reference">Reference</a>
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<ul>
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<li><a href="#creation">Parser Creation Functions</a>
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<ul>
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<li><a href="#XML_ParserCreate">XML_ParserCreate</a></li>
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<li><a href="#XML_ParserCreateNS">XML_ParserCreateNS</a></li>
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<li><a href="#XML_ParserCreate_MM">XML_ParserCreate_MM</a></li>
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<li><a href="#XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</a></li>
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<li><a href="#XML_ParserFree">XML_ParserFree</a></li>
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<li><a href="#XML_ParserReset">XML_ParserReset</a></li>
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</ul>
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</li>
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<li><a href="#parsing">Parsing Functions</a>
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<ul>
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<li><a href="#XML_Parse">XML_Parse</a></li>
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<li><a href="#XML_ParseBuffer">XML_ParseBuffer</a></li>
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<li><a href="#XML_GetBuffer">XML_GetBuffer</a></li>
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<li><a href="#XML_StopParser">XML_StopParser</a></li>
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<li><a href="#XML_ResumeParser">XML_ResumeParser</a></li>
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<li><a href="#XML_GetParsingStatus">XML_GetParsingStatus</a></li>
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</ul>
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</li>
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<li><a href="#setting">Handler Setting Functions</a>
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<ul>
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<li><a href="#XML_SetStartElementHandler">XML_SetStartElementHandler</a></li>
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<li><a href="#XML_SetEndElementHandler">XML_SetEndElementHandler</a></li>
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<li><a href="#XML_SetElementHandler">XML_SetElementHandler</a></li>
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<li><a href="#XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</a></li>
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<li><a href="#XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</a></li>
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<li><a href="#XML_SetCommentHandler">XML_SetCommentHandler</a></li>
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<li><a href="#XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</a></li>
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<li><a href="#XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</a></li>
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<li><a href="#XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</a></li>
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<li><a href="#XML_SetDefaultHandler">XML_SetDefaultHandler</a></li>
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<li><a href="#XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</a></li>
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<li><a href="#XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</a></li>
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<li><a href="#XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</a></li>
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<li><a href="#XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</a></li>
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<li><a href="#XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</a></li>
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<li><a href="#XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</a></li>
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<li><a href="#XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</a></li>
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<li><a href="#XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</a></li>
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<li><a href="#XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</a></li>
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<li><a href="#XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</a></li>
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<li><a href="#XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</a></li>
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<li><a href="#XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</a></li>
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<li><a href="#XML_SetElementDeclHandler">XML_SetElementDeclHandler</a></li>
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<li><a href="#XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</a></li>
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<li><a href="#XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</a></li>
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<li><a href="#XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</a></li>
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<li><a href="#XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</a></li>
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<li><a href="#XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</a></li>
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</ul>
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</li>
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<li><a href="#position">Parse Position and Error Reporting Functions</a>
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<ul>
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<li><a href="#XML_GetErrorCode">XML_GetErrorCode</a></li>
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<li><a href="#XML_ErrorString">XML_ErrorString</a></li>
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<li><a href="#XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</a></li>
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<li><a href="#XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</a></li>
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<li><a href="#XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</a></li>
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<li><a href="#XML_GetCurrentByteCount">XML_GetCurrentByteCount</a></li>
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<li><a href="#XML_GetInputContext">XML_GetInputContext</a></li>
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</ul>
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</li>
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<li><a href="#miscellaneous">Miscellaneous Functions</a>
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<ul>
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<li><a href="#XML_SetUserData">XML_SetUserData</a></li>
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<li><a href="#XML_GetUserData">XML_GetUserData</a></li>
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<li><a href="#XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</a></li>
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<li><a href="#XML_SetBase">XML_SetBase</a></li>
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<li><a href="#XML_GetBase">XML_GetBase</a></li>
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<li><a href="#XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</a></li>
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<li><a href="#XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</a></li>
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<li><a href="#XML_GetAttributeInfo">XML_GetAttributeInfo</a></li>
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<li><a href="#XML_SetEncoding">XML_SetEncoding</a></li>
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<li><a href="#XML_SetParamEntityParsing">XML_SetParamEntityParsing</a></li>
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<li><a href="#XML_SetHashSalt">XML_SetHashSalt</a></li>
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<li><a href="#XML_UseForeignDTD">XML_UseForeignDTD</a></li>
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<li><a href="#XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</a></li>
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<li><a href="#XML_DefaultCurrent">XML_DefaultCurrent</a></li>
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<li><a href="#XML_ExpatVersion">XML_ExpatVersion</a></li>
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<li><a href="#XML_ExpatVersionInfo">XML_ExpatVersionInfo</a></li>
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<li><a href="#XML_GetFeatureList">XML_GetFeatureList</a></li>
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<li><a href="#XML_FreeContentModel">XML_FreeContentModel</a></li>
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<li><a href="#XML_MemMalloc">XML_MemMalloc</a></li>
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<li><a href="#XML_MemRealloc">XML_MemRealloc</a></li>
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<li><a href="#XML_MemFree">XML_MemFree</a></li>
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</ul>
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</li>
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</ul>
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</li>
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</ul>
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<hr />
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<h2><a name="overview">Overview</a></h2>
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<p>Expat is a stream-oriented parser. You register callback (or
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handler) functions with the parser and then start feeding it the
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document. As the parser recognizes parts of the document, it will
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call the appropriate handler for that part (if you've registered one.)
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The document is fed to the parser in pieces, so you can start parsing
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before you have all the document. This also allows you to parse really
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huge documents that won't fit into memory.</p>
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<p>Expat can be intimidating due to the many kinds of handlers and
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options you can set. But you only need to learn four functions in
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order to do 90% of what you'll want to do with it:</p>
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<dl>
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<dt><code><a href= "#XML_ParserCreate"
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>XML_ParserCreate</a></code></dt>
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<dd>Create a new parser object.</dd>
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<dt><code><a href= "#XML_SetElementHandler"
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>XML_SetElementHandler</a></code></dt>
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<dd>Set handlers for start and end tags.</dd>
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<dt><code><a href= "#XML_SetCharacterDataHandler"
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>XML_SetCharacterDataHandler</a></code></dt>
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<dd>Set handler for text.</dd>
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<dt><code><a href= "#XML_Parse"
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>XML_Parse</a></code></dt>
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<dd>Pass a buffer full of document to the parser</dd>
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</dl>
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<p>These functions and others are described in the <a
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href="#reference">reference</a> part of this document. The reference
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section also describes in detail the parameters passed to the
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different types of handlers.</p>
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<p>Let's look at a very simple example program that only uses 3 of the
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above functions (it doesn't need to set a character handler.) The
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program <a href="../examples/outline.c">outline.c</a> prints an
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element outline, indenting child elements to distinguish them from the
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parent element that contains them. The start handler does all the
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work. It prints two indenting spaces for every level of ancestor
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elements, then it prints the element and attribute
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information. Finally it increments the global <code>Depth</code>
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variable.</p>
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<pre class="eg">
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int Depth;
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void XMLCALL
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start(void *data, const char *el, const char **attr) {
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int i;
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for (i = 0; i < Depth; i++)
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printf(" ");
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printf("%s", el);
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for (i = 0; attr[i]; i += 2) {
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printf(" %s='%s'", attr[i], attr[i + 1]);
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}
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printf("\n");
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Depth++;
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} /* End of start handler */
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</pre>
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<p>The end tag simply does the bookkeeping work of decrementing
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<code>Depth</code>.</p>
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<pre class="eg">
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void XMLCALL
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end(void *data, const char *el) {
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Depth--;
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} /* End of end handler */
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</pre>
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<p>Note the <code>XMLCALL</code> annotation used for the callbacks.
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This is used to ensure that the Expat and the callbacks are using the
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same calling convention in case the compiler options used for Expat
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itself and the client code are different. Expat tries not to care
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what the default calling convention is, though it may require that it
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be compiled with a default convention of "cdecl" on some platforms.
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For code which uses Expat, however, the calling convention is
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specified by the <code>XMLCALL</code> annotation on most platforms;
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callbacks should be defined using this annotation.</p>
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<p>The <code>XMLCALL</code> annotation was added in Expat 1.95.7, but
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existing working Expat applications don't need to add it (since they
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are already using the "cdecl" calling convention, or they wouldn't be
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working). The annotation is only needed if the default calling
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convention may be something other than "cdecl". To use the annotation
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safely with older versions of Expat, you can conditionally define it
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<em>after</em> including Expat's header file:</p>
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<pre class="eg">
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#include <expat.h>
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#ifndef XMLCALL
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#if defined(_MSC_EXTENSIONS) && !defined(__BEOS__) && !defined(__CYGWIN__)
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#define XMLCALL __cdecl
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#elif defined(__GNUC__)
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#define XMLCALL __attribute__((cdecl))
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#else
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#define XMLCALL
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#endif
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#endif
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</pre>
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<p>After creating the parser, the main program just has the job of
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shoveling the document to the parser so that it can do its work.</p>
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<hr />
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<h2><a name="building">Building and Installing Expat</a></h2>
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<p>The Expat distribution comes as a compressed (with GNU gzip) tar
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file. You may download the latest version from <a href=
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"http://sourceforge.net/projects/expat/" >Source Forge</a>. After
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unpacking this, cd into the directory. Then follow either the Win32
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directions or Unix directions below.</p>
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<h3>Building under Win32</h3>
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<p>If you're using the GNU compiler under cygwin, follow the Unix
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directions in the next section. Otherwise if you have Microsoft's
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Developer Studio installed, then from Windows Explorer double-click on
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"expat.dsp" in the lib directory and build and install in the usual
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manner.</p>
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<p>Alternatively, you may download the Win32 binary package that
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contains the "expat.h" include file and a pre-built DLL.</p>
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<h3>Building under Unix (or GNU)</h3>
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<p>First you'll need to run the configure shell script in order to
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configure the Makefiles and headers for your system.</p>
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<p>If you're happy with all the defaults that configure picks for you,
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and you have permission on your system to install into /usr/local, you
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can install Expat with this sequence of commands:</p>
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<pre class="eg">
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./configure
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make
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make install
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</pre>
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<p>There are some options that you can provide to this script, but the
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only one we'll mention here is the <code>--prefix</code> option. You
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can find out all the options available by running configure with just
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the <code>--help</code> option.</p>
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<p>By default, the configure script sets things up so that the library
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gets installed in <code>/usr/local/lib</code> and the associated
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header file in <code>/usr/local/include</code>. But if you were to
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give the option, <code>--prefix=/home/me/mystuff</code>, then the
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library and header would get installed in
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<code>/home/me/mystuff/lib</code> and
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<code>/home/me/mystuff/include</code> respectively.</p>
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<h3>Configuring Expat Using the Pre-Processor</h3>
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<p>Expat's feature set can be configured using a small number of
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pre-processor definitions. The definition of this symbols does not
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affect the set of entry points for Expat, only the behavior of the API
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and the definition of character types in the case of
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<code>XML_UNICODE_WCHAR_T</code>. The symbols are:</p>
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<dl class="cpp-symbols">
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<dt>XML_DTD</dt>
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<dd>Include support for using and reporting DTD-based content. If
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this is defined, default attribute values from an external DTD subset
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are reported and attribute value normalization occurs based on the
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type of attributes defined in the external subset. Without
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this, Expat has a smaller memory footprint and can be faster, but will
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not load external entities or process conditional sections. This does
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not affect the set of functions available in the API.</dd>
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<dt>XML_NS</dt>
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<dd>When defined, support for the <cite><a href=
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"http://www.w3.org/TR/REC-xml-names/" >Namespaces in XML</a></cite>
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specification is included.</dd>
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<dt>XML_UNICODE</dt>
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<dd>When defined, character data reported to the application is
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encoded in UTF-16 using wide characters of the type
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<code>XML_Char</code>. This is implied if
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<code>XML_UNICODE_WCHAR_T</code> is defined.</dd>
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<dt>XML_UNICODE_WCHAR_T</dt>
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<dd>If defined, causes the <code>XML_Char</code> character type to be
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defined using the <code>wchar_t</code> type; otherwise, <code>unsigned
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short</code> is used. Defining this implies
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<code>XML_UNICODE</code>.</dd>
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<dt>XML_LARGE_SIZE</dt>
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<dd>If defined, causes the <code>XML_Size</code> and <code>XML_Index</code>
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integer types to be at least 64 bits in size. This is intended to support
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processing of very large input streams, where the return values of
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<code><a href="#XML_GetCurrentByteIndex" >XML_GetCurrentByteIndex</a></code>,
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<code><a href="#XML_GetCurrentLineNumber" >XML_GetCurrentLineNumber</a></code> and
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<code><a href="#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>
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could overflow. It may not be supported by all compilers, and is turned
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off by default.</dd>
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<dt>XML_CONTEXT_BYTES</dt>
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<dd>The number of input bytes of markup context which the parser will
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ensure are available for reporting via <code><a href=
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"#XML_GetInputContext" >XML_GetInputContext</a></code>. This is
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normally set to 1024, and must be set to a positive interger. If this
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is not defined, the input context will not be available and <code><a
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href= "#XML_GetInputContext" >XML_GetInputContext</a></code> will
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always report NULL. Without this, Expat has a smaller memory
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footprint and can be faster.</dd>
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<dt>XML_STATIC</dt>
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<dd>On Windows, this should be set if Expat is going to be linked
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statically with the code that calls it; this is required to get all
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the right MSVC magic annotations correct. This is ignored on other
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platforms.</dd>
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<dt>XML_ATTR_INFO</dt>
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<dd>If defined, makes the the additional function <code><a href=
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"#XML_GetAttributeInfo" >XML_GetAttributeInfo</a></code> available
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for reporting attribute byte offsets.</dd>
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</dl>
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<hr />
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<h2><a name="using">Using Expat</a></h2>
|
|
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<h3>Compiling and Linking Against Expat</h3>
|
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<p>Unless you installed Expat in a location not expected by your
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compiler and linker, all you have to do to use Expat in your programs
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is to include the Expat header (<code>#include <expat.h></code>)
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in your files that make calls to it and to tell the linker that it
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needs to link against the Expat library. On Unix systems, this would
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usually be done with the <code>-lexpat</code> argument. Otherwise,
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you'll need to tell the compiler where to look for the Expat header
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|
and the linker where to find the Expat library. You may also need to
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take steps to tell the operating system where to find this library at
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run time.</p>
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<p>On a Unix-based system, here's what a Makefile might look like when
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Expat is installed in a standard location:</p>
|
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<pre class="eg">
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CC=cc
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LDFLAGS=
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LIBS= -lexpat
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xmlapp: xmlapp.o
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$(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS)
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</pre>
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|
|
<p>If you installed Expat in, say, <code>/home/me/mystuff</code>, then
|
|
the Makefile would look like this:</p>
|
|
|
|
<pre class="eg">
|
|
CC=cc
|
|
CFLAGS= -I/home/me/mystuff/include
|
|
LDFLAGS=
|
|
LIBS= -L/home/me/mystuff/lib -lexpat
|
|
xmlapp: xmlapp.o
|
|
$(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS)
|
|
</pre>
|
|
|
|
<p>You'd also have to set the environment variable
|
|
<code>LD_LIBRARY_PATH</code> to <code>/home/me/mystuff/lib</code> (or
|
|
to <code>${LD_LIBRARY_PATH}:/home/me/mystuff/lib</code> if
|
|
LD_LIBRARY_PATH already has some directories in it) in order to run
|
|
your application.</p>
|
|
|
|
<h3>Expat Basics</h3>
|
|
|
|
<p>As we saw in the example in the overview, the first step in parsing
|
|
an XML document with Expat is to create a parser object. There are <a
|
|
href="#creation">three functions</a> in the Expat API for creating a
|
|
parser object. However, only two of these (<code><a href=
|
|
"#XML_ParserCreate" >XML_ParserCreate</a></code> and <code><a href=
|
|
"#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>) can be used for
|
|
constructing a parser for a top-level document. The object returned
|
|
by these functions is an opaque pointer (i.e. "expat.h" declares it as
|
|
void *) to data with further internal structure. In order to free the
|
|
memory associated with this object you must call <code><a href=
|
|
"#XML_ParserFree" >XML_ParserFree</a></code>. Note that if you have
|
|
provided any <a href="#userdata">user data</a> that gets stored in the
|
|
parser, then your application is responsible for freeing it prior to
|
|
calling <code>XML_ParserFree</code>.</p>
|
|
|
|
<p>The objects returned by the parser creation functions are good for
|
|
parsing only one XML document or external parsed entity. If your
|
|
application needs to parse many XML documents, then it needs to create
|
|
a parser object for each one. The best way to deal with this is to
|
|
create a higher level object that contains all the default
|
|
initialization you want for your parser objects.</p>
|
|
|
|
<p>Walking through a document hierarchy with a stream oriented parser
|
|
will require a good stack mechanism in order to keep track of current
|
|
context. For instance, to answer the simple question, "What element
|
|
does this text belong to?" requires a stack, since the parser may have
|
|
descended into other elements that are children of the current one and
|
|
has encountered this text on the way out.</p>
|
|
|
|
<p>The things you're likely to want to keep on a stack are the
|
|
currently opened element and it's attributes. You push this
|
|
information onto the stack in the start handler and you pop it off in
|
|
the end handler.</p>
|
|
|
|
<p>For some tasks, it is sufficient to just keep information on what
|
|
the depth of the stack is (or would be if you had one.) The outline
|
|
program shown above presents one example. Another such task would be
|
|
skipping over a complete element. When you see the start tag for the
|
|
element you want to skip, you set a skip flag and record the depth at
|
|
which the element started. When the end tag handler encounters the
|
|
same depth, the skipped element has ended and the flag may be
|
|
cleared. If you follow the convention that the root element starts at
|
|
1, then you can use the same variable for skip flag and skip
|
|
depth.</p>
|
|
|
|
<pre class="eg">
|
|
void
|
|
init_info(Parseinfo *info) {
|
|
info->skip = 0;
|
|
info->depth = 1;
|
|
/* Other initializations here */
|
|
} /* End of init_info */
|
|
|
|
void XMLCALL
|
|
rawstart(void *data, const char *el, const char **attr) {
|
|
Parseinfo *inf = (Parseinfo *) data;
|
|
|
|
if (! inf->skip) {
|
|
if (should_skip(inf, el, attr)) {
|
|
inf->skip = inf->depth;
|
|
}
|
|
else
|
|
start(inf, el, attr); /* This does rest of start handling */
|
|
}
|
|
|
|
inf->depth++;
|
|
} /* End of rawstart */
|
|
|
|
void XMLCALL
|
|
rawend(void *data, const char *el) {
|
|
Parseinfo *inf = (Parseinfo *) data;
|
|
|
|
inf->depth--;
|
|
|
|
if (! inf->skip)
|
|
end(inf, el); /* This does rest of end handling */
|
|
|
|
if (inf->skip == inf->depth)
|
|
inf->skip = 0;
|
|
} /* End rawend */
|
|
</pre>
|
|
|
|
<p>Notice in the above example the difference in how depth is
|
|
manipulated in the start and end handlers. The end tag handler should
|
|
be the mirror image of the start tag handler. This is necessary to
|
|
properly model containment. Since, in the start tag handler, we
|
|
incremented depth <em>after</em> the main body of start tag code, then
|
|
in the end handler, we need to manipulate it <em>before</em> the main
|
|
body. If we'd decided to increment it first thing in the start
|
|
handler, then we'd have had to decrement it last thing in the end
|
|
handler.</p>
|
|
|
|
<h3 id="userdata">Communicating between handlers</h3>
|
|
|
|
<p>In order to be able to pass information between different handlers
|
|
without using globals, you'll need to define a data structure to hold
|
|
the shared variables. You can then tell Expat (with the <code><a href=
|
|
"#XML_SetUserData" >XML_SetUserData</a></code> function) to pass a
|
|
pointer to this structure to the handlers. This is the first
|
|
argument received by most handlers. In the <a href="#reference"
|
|
>reference section</a>, an argument to a callback function is named
|
|
<code>userData</code> and have type <code>void *</code> if the user
|
|
data is passed; it will have the type <code>XML_Parser</code> if the
|
|
parser itself is passed. When the parser is passed, the user data may
|
|
be retrieved using <code><a href="#XML_GetUserData"
|
|
>XML_GetUserData</a></code>.</p>
|
|
|
|
<p>One common case where multiple calls to a single handler may need
|
|
to communicate using an application data structure is the case when
|
|
content passed to the character data handler (set by <code><a href=
|
|
"#XML_SetCharacterDataHandler"
|
|
>XML_SetCharacterDataHandler</a></code>) needs to be accumulated. A
|
|
common first-time mistake with any of the event-oriented interfaces to
|
|
an XML parser is to expect all the text contained in an element to be
|
|
reported by a single call to the character data handler. Expat, like
|
|
many other XML parsers, reports such data as a sequence of calls;
|
|
there's no way to know when the end of the sequence is reached until a
|
|
different callback is made. A buffer referenced by the user data
|
|
structure proves both an effective and convenient place to accumulate
|
|
character data.</p>
|
|
|
|
<!-- XXX example needed here -->
|
|
|
|
|
|
<h3>XML Version</h3>
|
|
|
|
<p>Expat is an XML 1.0 parser, and as such never complains based on
|
|
the value of the <code>version</code> pseudo-attribute in the XML
|
|
declaration, if present.</p>
|
|
|
|
<p>If an application needs to check the version number (to support
|
|
alternate processing), it should use the <code><a href=
|
|
"#XML_SetXmlDeclHandler" >XML_SetXmlDeclHandler</a></code> function to
|
|
set a handler that uses the information in the XML declaration to
|
|
determine what to do. This example shows how to check that only a
|
|
version number of <code>"1.0"</code> is accepted:</p>
|
|
|
|
<pre class="eg">
|
|
static int wrong_version;
|
|
static XML_Parser parser;
|
|
|
|
static void XMLCALL
|
|
xmldecl_handler(void *userData,
|
|
const XML_Char *version,
|
|
const XML_Char *encoding,
|
|
int standalone)
|
|
{
|
|
static const XML_Char Version_1_0[] = {'1', '.', '0', 0};
|
|
|
|
int i;
|
|
|
|
for (i = 0; i < (sizeof(Version_1_0) / sizeof(Version_1_0[0])); ++i) {
|
|
if (version[i] != Version_1_0[i]) {
|
|
wrong_version = 1;
|
|
/* also clear all other handlers: */
|
|
XML_SetCharacterDataHandler(parser, NULL);
|
|
...
|
|
return;
|
|
}
|
|
}
|
|
...
|
|
}
|
|
</pre>
|
|
|
|
<h3>Namespace Processing</h3>
|
|
|
|
<p>When the parser is created using the <code><a href=
|
|
"#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, function, Expat
|
|
performs namespace processing. Under namespace processing, Expat
|
|
consumes <code>xmlns</code> and <code>xmlns:...</code> attributes,
|
|
which declare namespaces for the scope of the element in which they
|
|
occur. This means that your start handler will not see these
|
|
attributes. Your application can still be informed of these
|
|
declarations by setting namespace declaration handlers with <a href=
|
|
"#XML_SetNamespaceDeclHandler"
|
|
><code>XML_SetNamespaceDeclHandler</code></a>.</p>
|
|
|
|
<p>Element type and attribute names that belong to a given namespace
|
|
are passed to the appropriate handler in expanded form. By default
|
|
this expanded form is a concatenation of the namespace URI, the
|
|
separator character (which is the 2nd argument to <code><a href=
|
|
"#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>), and the local
|
|
name (i.e. the part after the colon). Names with undeclared prefixes
|
|
are not well-formed when namespace processing is enabled, and will
|
|
trigger an error. Unprefixed attribute names are never expanded,
|
|
and unprefixed element names are only expanded when they are in the
|
|
scope of a default namespace.</p>
|
|
|
|
<p>However if <code><a href= "#XML_SetReturnNSTriplet"
|
|
>XML_SetReturnNSTriplet</a></code> has been called with a non-zero
|
|
<code>do_nst</code> parameter, then the expanded form for names with
|
|
an explicit prefix is a concatenation of: URI, separator, local name,
|
|
separator, prefix.</p>
|
|
|
|
<p>You can set handlers for the start of a namespace declaration and
|
|
for the end of a scope of a declaration with the <code><a href=
|
|
"#XML_SetNamespaceDeclHandler" >XML_SetNamespaceDeclHandler</a></code>
|
|
function. The StartNamespaceDeclHandler is called prior to the start
|
|
tag handler and the EndNamespaceDeclHandler is called after the
|
|
corresponding end tag that ends the namespace's scope. The namespace
|
|
start handler gets passed the prefix and URI for the namespace. For a
|
|
default namespace declaration (xmlns='...'), the prefix will be null.
|
|
The URI will be null for the case where the default namespace is being
|
|
unset. The namespace end handler just gets the prefix for the closing
|
|
scope.</p>
|
|
|
|
<p>These handlers are called for each declaration. So if, for
|
|
instance, a start tag had three namespace declarations, then the
|
|
StartNamespaceDeclHandler would be called three times before the start
|
|
tag handler is called, once for each declaration.</p>
|
|
|
|
<h3>Character Encodings</h3>
|
|
|
|
<p>While XML is based on Unicode, and every XML processor is required
|
|
to recognized UTF-8 and UTF-16 (1 and 2 byte encodings of Unicode),
|
|
other encodings may be declared in XML documents or entities. For the
|
|
main document, an XML declaration may contain an encoding
|
|
declaration:</p>
|
|
<pre>
|
|
<?xml version="1.0" encoding="ISO-8859-2"?>
|
|
</pre>
|
|
|
|
<p>External parsed entities may begin with a text declaration, which
|
|
looks like an XML declaration with just an encoding declaration:</p>
|
|
<pre>
|
|
<?xml encoding="Big5"?>
|
|
</pre>
|
|
|
|
<p>With Expat, you may also specify an encoding at the time of
|
|
creating a parser. This is useful when the encoding information may
|
|
come from a source outside the document itself (like a higher level
|
|
protocol.)</p>
|
|
|
|
<p><a name="builtin_encodings"></a>There are four built-in encodings
|
|
in Expat:</p>
|
|
<ul>
|
|
<li>UTF-8</li>
|
|
<li>UTF-16</li>
|
|
<li>ISO-8859-1</li>
|
|
<li>US-ASCII</li>
|
|
</ul>
|
|
|
|
<p>Anything else discovered in an encoding declaration or in the
|
|
protocol encoding specified in the parser constructor, triggers a call
|
|
to the <code>UnknownEncodingHandler</code>. This handler gets passed
|
|
the encoding name and a pointer to an <code>XML_Encoding</code> data
|
|
structure. Your handler must fill in this structure and return
|
|
<code>XML_STATUS_OK</code> if it knows how to deal with the
|
|
encoding. Otherwise the handler should return
|
|
<code>XML_STATUS_ERROR</code>. The handler also gets passed a pointer
|
|
to an optional application data structure that you may indicate when
|
|
you set the handler.</p>
|
|
|
|
<p>Expat places restrictions on character encodings that it can
|
|
support by filling in the <code>XML_Encoding</code> structure.
|
|
include file:</p>
|
|
<ol>
|
|
<li>Every ASCII character that can appear in a well-formed XML document
|
|
must be represented by a single byte, and that byte must correspond to
|
|
it's ASCII encoding (except for the characters $@\^'{}~)</li>
|
|
<li>Characters must be encoded in 4 bytes or less.</li>
|
|
<li>All characters encoded must have Unicode scalar values less than or
|
|
equal to 65535 (0xFFFF)<em>This does not apply to the built-in support
|
|
for UTF-16 and UTF-8</em></li>
|
|
<li>No character may be encoded by more that one distinct sequence of
|
|
bytes</li>
|
|
</ol>
|
|
|
|
<p><code>XML_Encoding</code> contains an array of integers that
|
|
correspond to the 1st byte of an encoding sequence. If the value in
|
|
the array for a byte is zero or positive, then the byte is a single
|
|
byte encoding that encodes the Unicode scalar value contained in the
|
|
array. A -1 in this array indicates a malformed byte. If the value is
|
|
-2, -3, or -4, then the byte is the beginning of a 2, 3, or 4 byte
|
|
sequence respectively. Multi-byte sequences are sent to the convert
|
|
function pointed at in the <code>XML_Encoding</code> structure. This
|
|
function should return the Unicode scalar value for the sequence or -1
|
|
if the sequence is malformed.</p>
|
|
|
|
<p>One pitfall that novice Expat users are likely to fall into is that
|
|
although Expat may accept input in various encodings, the strings that
|
|
it passes to the handlers are always encoded in UTF-8 or UTF-16
|
|
(depending on how Expat was compiled). Your application is responsible
|
|
for any translation of these strings into other encodings.</p>
|
|
|
|
<h3>Handling External Entity References</h3>
|
|
|
|
<p>Expat does not read or parse external entities directly. Note that
|
|
any external DTD is a special case of an external entity. If you've
|
|
set no <code>ExternalEntityRefHandler</code>, then external entity
|
|
references are silently ignored. Otherwise, it calls your handler with
|
|
the information needed to read and parse the external entity.</p>
|
|
|
|
<p>Your handler isn't actually responsible for parsing the entity, but
|
|
it is responsible for creating a subsidiary parser with <code><a href=
|
|
"#XML_ExternalEntityParserCreate"
|
|
>XML_ExternalEntityParserCreate</a></code> that will do the job. This
|
|
returns an instance of <code>XML_Parser</code> that has handlers and
|
|
other data structures initialized from the parent parser. You may then
|
|
use <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a
|
|
href= "#XML_ParseBuffer">XML_ParseBuffer</a></code> calls against this
|
|
parser. Since external entities my refer to other external entities,
|
|
your handler should be prepared to be called recursively.</p>
|
|
|
|
<h3>Parsing DTDs</h3>
|
|
|
|
<p>In order to parse parameter entities, before starting the parse,
|
|
you must call <code><a href= "#XML_SetParamEntityParsing"
|
|
>XML_SetParamEntityParsing</a></code> with one of the following
|
|
arguments:</p>
|
|
<dl>
|
|
<dt><code>XML_PARAM_ENTITY_PARSING_NEVER</code></dt>
|
|
<dd>Don't parse parameter entities or the external subset</dd>
|
|
<dt><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></dt>
|
|
<dd>Parse parameter entites and the external subset unless
|
|
<code>standalone</code> was set to "yes" in the XML declaration.</dd>
|
|
<dt><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></dt>
|
|
<dd>Always parse parameter entities and the external subset</dd>
|
|
</dl>
|
|
|
|
<p>In order to read an external DTD, you also have to set an external
|
|
entity reference handler as described above.</p>
|
|
|
|
<h3 id="stop-resume">Temporarily Stopping Parsing</h3>
|
|
|
|
<p>Expat 1.95.8 introduces a new feature: its now possible to stop
|
|
parsing temporarily from within a handler function, even if more data
|
|
has already been passed into the parser. Applications for this
|
|
include</p>
|
|
|
|
<ul>
|
|
<li>Supporting the <a href= "http://www.w3.org/TR/xinclude/"
|
|
>XInclude</a> specification.</li>
|
|
|
|
<li>Delaying further processing until additional information is
|
|
available from some other source.</li>
|
|
|
|
<li>Adjusting processor load as task priorities shift within an
|
|
application.</li>
|
|
|
|
<li>Stopping parsing completely (simply free or reset the parser
|
|
instead of resuming in the outer parsing loop). This can be useful
|
|
if a application-domain error is found in the XML being parsed or if
|
|
the result of the parse is determined not to be useful after
|
|
all.</li>
|
|
</ul>
|
|
|
|
<p>To take advantage of this feature, the main parsing loop of an
|
|
application needs to support this specifically. It cannot be
|
|
supported with a parsing loop compatible with Expat 1.95.7 or
|
|
earlier (though existing loops will continue to work without
|
|
supporting the stop/resume feature).</p>
|
|
|
|
<p>An application that uses this feature for a single parser will have
|
|
the rough structure (in pseudo-code):</p>
|
|
|
|
<pre class="pseudocode">
|
|
fd = open_input()
|
|
p = create_parser()
|
|
|
|
if parse_xml(p, fd) {
|
|
/* suspended */
|
|
|
|
int suspended = 1;
|
|
|
|
while (suspended) {
|
|
do_something_else()
|
|
if ready_to_resume() {
|
|
suspended = continue_parsing(p, fd);
|
|
}
|
|
}
|
|
}
|
|
</pre>
|
|
|
|
<p>An application that may resume any of several parsers based on
|
|
input (either from the XML being parsed or some other source) will
|
|
certainly have more interesting control structures.</p>
|
|
|
|
<p>This C function could be used for the <code>parse_xml</code>
|
|
function mentioned in the pseudo-code above:</p>
|
|
|
|
<pre class="eg">
|
|
#define BUFF_SIZE 10240
|
|
|
|
/* Parse a document from the open file descriptor 'fd' until the parse
|
|
is complete (the document has been completely parsed, or there's
|
|
been an error), or the parse is stopped. Return non-zero when
|
|
the parse is merely suspended.
|
|
*/
|
|
int
|
|
parse_xml(XML_Parser p, int fd)
|
|
{
|
|
for (;;) {
|
|
int last_chunk;
|
|
int bytes_read;
|
|
enum XML_Status status;
|
|
|
|
void *buff = XML_GetBuffer(p, BUFF_SIZE);
|
|
if (buff == NULL) {
|
|
/* handle error... */
|
|
return 0;
|
|
}
|
|
bytes_read = read(fd, buff, BUFF_SIZE);
|
|
if (bytes_read < 0) {
|
|
/* handle error... */
|
|
return 0;
|
|
}
|
|
status = XML_ParseBuffer(p, bytes_read, bytes_read == 0);
|
|
switch (status) {
|
|
case XML_STATUS_ERROR:
|
|
/* handle error... */
|
|
return 0;
|
|
case XML_STATUS_SUSPENDED:
|
|
return 1;
|
|
}
|
|
if (bytes_read == 0)
|
|
return 0;
|
|
}
|
|
}
|
|
</pre>
|
|
|
|
<p>The corresponding <code>continue_parsing</code> function is
|
|
somewhat simpler, since it only need deal with the return code from
|
|
<code><a href= "#XML_ResumeParser">XML_ResumeParser</a></code>; it can
|
|
delegate the input handling to the <code>parse_xml</code>
|
|
function:</p>
|
|
|
|
<pre class="eg">
|
|
/* Continue parsing a document which had been suspended. The 'p' and
|
|
'fd' arguments are the same as passed to parse_xml(). Return
|
|
non-zero when the parse is suspended.
|
|
*/
|
|
int
|
|
continue_parsing(XML_Parser p, int fd)
|
|
{
|
|
enum XML_Status status = XML_ResumeParser(p);
|
|
switch (status) {
|
|
case XML_STATUS_ERROR:
|
|
/* handle error... */
|
|
return 0;
|
|
case XML_ERROR_NOT_SUSPENDED:
|
|
/* handle error... */
|
|
return 0;.
|
|
case XML_STATUS_SUSPENDED:
|
|
return 1;
|
|
}
|
|
return parse_xml(p, fd);
|
|
}
|
|
</pre>
|
|
|
|
<p>Now that we've seen what a mess the top-level parsing loop can
|
|
become, what have we gained? Very simply, we can now use the <code><a
|
|
href= "#XML_StopParser" >XML_StopParser</a></code> function to stop
|
|
parsing, without having to go to great lengths to avoid additional
|
|
processing that we're expecting to ignore. As a bonus, we get to stop
|
|
parsing <em>temporarily</em>, and come back to it when we're
|
|
ready.</p>
|
|
|
|
<p>To stop parsing from a handler function, use the <code><a href=
|
|
"#XML_StopParser" >XML_StopParser</a></code> function. This function
|
|
takes two arguments; the parser being stopped and a flag indicating
|
|
whether the parse can be resumed in the future.</p>
|
|
|
|
<!-- XXX really need more here -->
|
|
|
|
|
|
<hr />
|
|
<!-- ================================================================ -->
|
|
|
|
<h2><a name="reference">Expat Reference</a></h2>
|
|
|
|
<h3><a name="creation">Parser Creation</a></h3>
|
|
|
|
<pre class="fcndec" id="XML_ParserCreate">
|
|
XML_Parser XMLCALL
|
|
XML_ParserCreate(const XML_Char *encoding);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Construct a new parser. If encoding is non-null, it specifies a
|
|
character encoding to use for the document. This overrides the document
|
|
encoding declaration. There are four built-in encodings:
|
|
<ul>
|
|
<li>US-ASCII</li>
|
|
<li>UTF-8</li>
|
|
<li>UTF-16</li>
|
|
<li>ISO-8859-1</li>
|
|
</ul>
|
|
Any other value will invoke a call to the UnknownEncodingHandler.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ParserCreateNS">
|
|
XML_Parser XMLCALL
|
|
XML_ParserCreateNS(const XML_Char *encoding,
|
|
XML_Char sep);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Constructs a new parser that has namespace processing in effect. Namespace
|
|
expanded element names and attribute names are returned as a concatenation
|
|
of the namespace URI, <em>sep</em>, and the local part of the name. This
|
|
means that you should pick a character for <em>sep</em> that can't be part
|
|
of an URI. Since Expat does not check namespace URIs for conformance, the
|
|
only safe choice for a namespace separator is a character that is illegal
|
|
in XML. For instance, <code>'\xFF'</code> is not legal in UTF-8, and
|
|
<code>'\xFFFF'</code> is not legal in UTF-16. There is a special case when
|
|
<em>sep</em> is the null character <code>'\0'</code>: the namespace URI and
|
|
the local part will be concatenated without any separator - this is intended
|
|
to support RDF processors. It is a programming error to use the null separator
|
|
with <a href= "#XML_SetReturnNSTriplet">namespace triplets</a>.</div>
|
|
|
|
<pre class="fcndec" id="XML_ParserCreate_MM">
|
|
XML_Parser XMLCALL
|
|
XML_ParserCreate_MM(const XML_Char *encoding,
|
|
const XML_Memory_Handling_Suite *ms,
|
|
const XML_Char *sep);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef struct {
|
|
void *(XMLCALL *malloc_fcn)(size_t size);
|
|
void *(XMLCALL *realloc_fcn)(void *ptr, size_t size);
|
|
void (XMLCALL *free_fcn)(void *ptr);
|
|
} XML_Memory_Handling_Suite;
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>Construct a new parser using the suite of memory handling functions
|
|
specified in <code>ms</code>. If <code>ms</code> is NULL, then use the
|
|
standard set of memory management functions. If <code>sep</code> is
|
|
non NULL, then namespace processing is enabled in the created parser
|
|
and the character pointed at by sep is used as the separator between
|
|
the namespace URI and the local part of the name.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ExternalEntityParserCreate">
|
|
XML_Parser XMLCALL
|
|
XML_ExternalEntityParserCreate(XML_Parser p,
|
|
const XML_Char *context,
|
|
const XML_Char *encoding);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Construct a new <code>XML_Parser</code> object for parsing an external
|
|
general entity. Context is the context argument passed in a call to a
|
|
ExternalEntityRefHandler. Other state information such as handlers,
|
|
user data, namespace processing is inherited from the parser passed as
|
|
the 1st argument. So you shouldn't need to call any of the behavior
|
|
changing functions on this parser (unless you want it to act
|
|
differently than the parent parser).
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ParserFree">
|
|
void XMLCALL
|
|
XML_ParserFree(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Free memory used by the parser. Your application is responsible for
|
|
freeing any memory associated with <a href="#userdata">user data</a>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ParserReset">
|
|
XML_Bool XMLCALL
|
|
XML_ParserReset(XML_Parser p,
|
|
const XML_Char *encoding);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Clean up the memory structures maintained by the parser so that it may
|
|
be used again. After this has been called, <code>parser</code> is
|
|
ready to start parsing a new document. All handlers are cleared from
|
|
the parser, except for the unknownEncodingHandler. The parser's external
|
|
state is re-initialized except for the values of ns and ns_triplets.
|
|
This function may not be used on a parser created using <code><a href=
|
|
"#XML_ExternalEntityParserCreate" >XML_ExternalEntityParserCreate</a
|
|
></code>; it will return <code>XML_FALSE</code> in that case. Returns
|
|
<code>XML_TRUE</code> on success. Your application is responsible for
|
|
dealing with any memory associated with <a href="#userdata">user data</a>.
|
|
</div>
|
|
|
|
<h3><a name="parsing">Parsing</a></h3>
|
|
|
|
<p>To state the obvious: the three parsing functions <code><a href=
|
|
"#XML_Parse" >XML_Parse</a></code>, <code><a href= "#XML_ParseBuffer">
|
|
XML_ParseBuffer</a></code> and <code><a href= "#XML_GetBuffer">
|
|
XML_GetBuffer</a></code> must not be called from within a handler
|
|
unless they operate on a separate parser instance, that is, one that
|
|
did not call the handler. For example, it is OK to call the parsing
|
|
functions from within an <code>XML_ExternalEntityRefHandler</code>,
|
|
if they apply to the parser created by
|
|
<code><a href= "#XML_ExternalEntityParserCreate"
|
|
>XML_ExternalEntityParserCreate</a></code>.</p>
|
|
|
|
<p>Note: the <code>len</code> argument passed to these functions
|
|
should be considerably less than the maximum value for an integer,
|
|
as it could create an integer overflow situation if the added
|
|
lengths of a buffer and the unprocessed portion of the previous buffer
|
|
exceed the maximum integer value. Input data at the end of a buffer
|
|
will remain unprocessed if it is part of an XML token for which the
|
|
end is not part of that buffer.</p>
|
|
|
|
<pre class="fcndec" id="XML_Parse">
|
|
enum XML_Status XMLCALL
|
|
XML_Parse(XML_Parser p,
|
|
const char *s,
|
|
int len,
|
|
int isFinal);
|
|
</pre>
|
|
<pre class="signature">
|
|
enum XML_Status {
|
|
XML_STATUS_ERROR = 0,
|
|
XML_STATUS_OK = 1
|
|
};
|
|
</pre>
|
|
<div class="fcndef">
|
|
Parse some more of the document. The string <code>s</code> is a buffer
|
|
containing part (or perhaps all) of the document. The number of bytes of s
|
|
that are part of the document is indicated by <code>len</code>. This means
|
|
that <code>s</code> doesn't have to be null terminated. It also means that
|
|
if <code>len</code> is larger than the number of bytes in the block of
|
|
memory that <code>s</code> points at, then a memory fault is likely. The
|
|
<code>isFinal</code> parameter informs the parser that this is the last
|
|
piece of the document. Frequently, the last piece is empty (i.e.
|
|
<code>len</code> is zero.)
|
|
If a parse error occurred, it returns <code>XML_STATUS_ERROR</code>.
|
|
Otherwise it returns <code>XML_STATUS_OK</code> value.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ParseBuffer">
|
|
enum XML_Status XMLCALL
|
|
XML_ParseBuffer(XML_Parser p,
|
|
int len,
|
|
int isFinal);
|
|
</pre>
|
|
<div class="fcndef">
|
|
This is just like <code><a href= "#XML_Parse" >XML_Parse</a></code>,
|
|
except in this case Expat provides the buffer. By obtaining the
|
|
buffer from Expat with the <code><a href= "#XML_GetBuffer"
|
|
>XML_GetBuffer</a></code> function, the application can avoid double
|
|
copying of the input.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetBuffer">
|
|
void * XMLCALL
|
|
XML_GetBuffer(XML_Parser p,
|
|
int len);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Obtain a buffer of size <code>len</code> to read a piece of the document
|
|
into. A NULL value is returned if Expat can't allocate enough memory for
|
|
this buffer. This has to be called prior to every call to
|
|
<code><a href= "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. A
|
|
typical use would look like this:
|
|
|
|
<pre class="eg">
|
|
for (;;) {
|
|
int bytes_read;
|
|
void *buff = XML_GetBuffer(p, BUFF_SIZE);
|
|
if (buff == NULL) {
|
|
/* handle error */
|
|
}
|
|
|
|
bytes_read = read(docfd, buff, BUFF_SIZE);
|
|
if (bytes_read < 0) {
|
|
/* handle error */
|
|
}
|
|
|
|
if (! XML_ParseBuffer(p, bytes_read, bytes_read == 0)) {
|
|
/* handle parse error */
|
|
}
|
|
|
|
if (bytes_read == 0)
|
|
break;
|
|
}
|
|
</pre>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_StopParser">
|
|
enum XML_Status XMLCALL
|
|
XML_StopParser(XML_Parser p,
|
|
XML_Bool resumable);
|
|
</pre>
|
|
<div class="fcndef">
|
|
|
|
<p>Stops parsing, causing <code><a href= "#XML_Parse"
|
|
>XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer"
|
|
>XML_ParseBuffer</a></code> to return. Must be called from within a
|
|
call-back handler, except when aborting (when <code>resumable</code>
|
|
is <code>XML_FALSE</code>) an already suspended parser. Some
|
|
call-backs may still follow because they would otherwise get
|
|
lost, including
|
|
<ul>
|
|
<li> the end element handler for empty elements when stopped in the
|
|
start element handler,</li>
|
|
<li> the end namespace declaration handler when stopped in the end
|
|
element handler,</li>
|
|
<li> the character data handler when stopped in the character data handler
|
|
while making multiple call-backs on a contiguous chunk of characters,</li>
|
|
</ul>
|
|
and possibly others.</p>
|
|
|
|
<p>This can be called from most handlers, including DTD related
|
|
call-backs, except when parsing an external parameter entity and
|
|
<code>resumable</code> is <code>XML_TRUE</code>. Returns
|
|
<code>XML_STATUS_OK</code> when successful,
|
|
<code>XML_STATUS_ERROR</code> otherwise. The possible error codes
|
|
are:</p>
|
|
<dl>
|
|
<dt><code>XML_ERROR_SUSPENDED</code></dt>
|
|
<dd>when suspending an already suspended parser.</dd>
|
|
<dt><code>XML_ERROR_FINISHED</code></dt>
|
|
<dd>when the parser has already finished.</dd>
|
|
<dt><code>XML_ERROR_SUSPEND_PE</code></dt>
|
|
<dd>when suspending while parsing an external PE.</dd>
|
|
</dl>
|
|
|
|
<p>Since the stop/resume feature requires application support in the
|
|
outer parsing loop, it is an error to call this function for a parser
|
|
not being handled appropriately; see <a href= "#stop-resume"
|
|
>Temporarily Stopping Parsing</a> for more information.</p>
|
|
|
|
<p>When <code>resumable</code> is <code>XML_TRUE</code> then parsing
|
|
is <em>suspended</em>, that is, <code><a href= "#XML_Parse"
|
|
>XML_Parse</a></code> and <code><a href= "#XML_ParseBuffer"
|
|
>XML_ParseBuffer</a></code> return <code>XML_STATUS_SUSPENDED</code>.
|
|
Otherwise, parsing is <em>aborted</em>, that is, <code><a href=
|
|
"#XML_Parse" >XML_Parse</a></code> and <code><a href=
|
|
"#XML_ParseBuffer" >XML_ParseBuffer</a></code> return
|
|
<code>XML_STATUS_ERROR</code> with error code
|
|
<code>XML_ERROR_ABORTED</code>.</p>
|
|
|
|
<p><strong>Note:</strong>
|
|
This will be applied to the current parser instance only, that is, if
|
|
there is a parent parser then it will continue parsing when the
|
|
external entity reference handler returns. It is up to the
|
|
implementation of that handler to call <code><a href=
|
|
"#XML_StopParser" >XML_StopParser</a></code> on the parent parser
|
|
(recursively), if one wants to stop parsing altogether.</p>
|
|
|
|
<p>When suspended, parsing can be resumed by calling <code><a href=
|
|
"#XML_ResumeParser" >XML_ResumeParser</a></code>.</p>
|
|
|
|
<p>New in Expat 1.95.8.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ResumeParser">
|
|
enum XML_Status XMLCALL
|
|
XML_ResumeParser(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>Resumes parsing after it has been suspended with <code><a href=
|
|
"#XML_StopParser" >XML_StopParser</a></code>. Must not be called from
|
|
within a handler call-back. Returns same status codes as <code><a
|
|
href= "#XML_Parse">XML_Parse</a></code> or <code><a href=
|
|
"#XML_ParseBuffer" >XML_ParseBuffer</a></code>. An additional error
|
|
code, <code>XML_ERROR_NOT_SUSPENDED</code>, will be returned if the
|
|
parser was not currently suspended.</p>
|
|
|
|
<p><strong>Note:</strong>
|
|
This must be called on the most deeply nested child parser instance
|
|
first, and on its parent parser only after the child parser has
|
|
finished, to be applied recursively until the document entity's parser
|
|
is restarted. That is, the parent parser will not resume by itself
|
|
and it is up to the application to call <code><a href=
|
|
"#XML_ResumeParser" >XML_ResumeParser</a></code> on it at the
|
|
appropriate moment.</p>
|
|
|
|
<p>New in Expat 1.95.8.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetParsingStatus">
|
|
void XMLCALL
|
|
XML_GetParsingStatus(XML_Parser p,
|
|
XML_ParsingStatus *status);
|
|
</pre>
|
|
<pre class="signature">
|
|
enum XML_Parsing {
|
|
XML_INITIALIZED,
|
|
XML_PARSING,
|
|
XML_FINISHED,
|
|
XML_SUSPENDED
|
|
};
|
|
|
|
typedef struct {
|
|
enum XML_Parsing parsing;
|
|
XML_Bool finalBuffer;
|
|
} XML_ParsingStatus;
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>Returns status of parser with respect to being initialized,
|
|
parsing, finished, or suspended, and whether the final buffer is being
|
|
processed. The <code>status</code> parameter <em>must not</em> be
|
|
NULL.</p>
|
|
|
|
<p>New in Expat 1.95.8.</p>
|
|
</div>
|
|
|
|
|
|
<h3><a name="setting">Handler Setting</a></h3>
|
|
|
|
<p>Although handlers are typically set prior to parsing and left alone, an
|
|
application may choose to set or change the handler for a parsing event
|
|
while the parse is in progress. For instance, your application may choose
|
|
to ignore all text not descended from a <code>para</code> element. One
|
|
way it could do this is to set the character handler when a para start tag
|
|
is seen, and unset it for the corresponding end tag.</p>
|
|
|
|
<p>A handler may be <em>unset</em> by providing a NULL pointer to the
|
|
appropriate handler setter. None of the handler setting functions have
|
|
a return value.</p>
|
|
|
|
<p>Your handlers will be receiving strings in arrays of type
|
|
<code>XML_Char</code>. This type is conditionally defined in expat.h as
|
|
either <code>char</code>, <code>wchar_t</code> or <code>unsigned short</code>.
|
|
The former implies UTF-8 encoding, the latter two imply UTF-16 encoding.
|
|
Note that you'll receive them in this form independent of the original
|
|
encoding of the document.</p>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetStartElementHandler">
|
|
void XMLCALL
|
|
XML_SetStartElementHandler(XML_Parser p,
|
|
XML_StartElementHandler start);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_StartElementHandler)(void *userData,
|
|
const XML_Char *name,
|
|
const XML_Char **atts);
|
|
</pre>
|
|
<p>Set handler for start (and empty) tags. Attributes are passed to the start
|
|
handler as a pointer to a vector of char pointers. Each attribute seen in
|
|
a start (or empty) tag occupies 2 consecutive places in this vector: the
|
|
attribute name followed by the attribute value. These pairs are terminated
|
|
by a null pointer.</p>
|
|
<p>Note that an empty tag generates a call to both start and end handlers
|
|
(in that order).</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetEndElementHandler">
|
|
void XMLCALL
|
|
XML_SetEndElementHandler(XML_Parser p,
|
|
XML_EndElementHandler);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_EndElementHandler)(void *userData,
|
|
const XML_Char *name);
|
|
</pre>
|
|
<p>Set handler for end (and empty) tags. As noted above, an empty tag
|
|
generates a call to both start and end handlers.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetElementHandler">
|
|
void XMLCALL
|
|
XML_SetElementHandler(XML_Parser p,
|
|
XML_StartElementHandler start,
|
|
XML_EndElementHandler end);
|
|
</pre>
|
|
<p>Set handlers for start and end tags with one call.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetCharacterDataHandler">
|
|
void XMLCALL
|
|
XML_SetCharacterDataHandler(XML_Parser p,
|
|
XML_CharacterDataHandler charhndl)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_CharacterDataHandler)(void *userData,
|
|
const XML_Char *s,
|
|
int len);
|
|
</pre>
|
|
<p>Set a text handler. The string your handler receives
|
|
is <em>NOT nul-terminated</em>. You have to use the length argument
|
|
to deal with the end of the string. A single block of contiguous text
|
|
free of markup may still result in a sequence of calls to this handler.
|
|
In other words, if you're searching for a pattern in the text, it may
|
|
be split across calls to this handler. Note: Setting this handler to NULL
|
|
may <em>NOT immediately</em> terminate call-backs if the parser is currently
|
|
processing such a single block of contiguous markup-free text, as the parser
|
|
will continue calling back until the end of the block is reached.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetProcessingInstructionHandler">
|
|
void XMLCALL
|
|
XML_SetProcessingInstructionHandler(XML_Parser p,
|
|
XML_ProcessingInstructionHandler proc)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_ProcessingInstructionHandler)(void *userData,
|
|
const XML_Char *target,
|
|
const XML_Char *data);
|
|
|
|
</pre>
|
|
<p>Set a handler for processing instructions. The target is the first word
|
|
in the processing instruction. The data is the rest of the characters in
|
|
it after skipping all whitespace after the initial word.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetCommentHandler">
|
|
void XMLCALL
|
|
XML_SetCommentHandler(XML_Parser p,
|
|
XML_CommentHandler cmnt)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_CommentHandler)(void *userData,
|
|
const XML_Char *data);
|
|
</pre>
|
|
<p>Set a handler for comments. The data is all text inside the comment
|
|
delimiters.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetStartCdataSectionHandler">
|
|
void XMLCALL
|
|
XML_SetStartCdataSectionHandler(XML_Parser p,
|
|
XML_StartCdataSectionHandler start);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_StartCdataSectionHandler)(void *userData);
|
|
</pre>
|
|
<p>Set a handler that gets called at the beginning of a CDATA section.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetEndCdataSectionHandler">
|
|
void XMLCALL
|
|
XML_SetEndCdataSectionHandler(XML_Parser p,
|
|
XML_EndCdataSectionHandler end);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_EndCdataSectionHandler)(void *userData);
|
|
</pre>
|
|
<p>Set a handler that gets called at the end of a CDATA section.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetCdataSectionHandler">
|
|
void XMLCALL
|
|
XML_SetCdataSectionHandler(XML_Parser p,
|
|
XML_StartCdataSectionHandler start,
|
|
XML_EndCdataSectionHandler end)
|
|
</pre>
|
|
<p>Sets both CDATA section handlers with one call.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetDefaultHandler">
|
|
void XMLCALL
|
|
XML_SetDefaultHandler(XML_Parser p,
|
|
XML_DefaultHandler hndl)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_DefaultHandler)(void *userData,
|
|
const XML_Char *s,
|
|
int len);
|
|
</pre>
|
|
|
|
<p>Sets a handler for any characters in the document which wouldn't
|
|
otherwise be handled. This includes both data for which no handlers
|
|
can be set (like some kinds of DTD declarations) and data which could
|
|
be reported but which currently has no handler set. The characters
|
|
are passed exactly as they were present in the XML document except
|
|
that they will be encoded in UTF-8 or UTF-16. Line boundaries are not
|
|
normalized. Note that a byte order mark character is not passed to the
|
|
default handler. There are no guarantees about how characters are
|
|
divided between calls to the default handler: for example, a comment
|
|
might be split between multiple calls. Setting the handler with
|
|
this call has the side effect of turning off expansion of references
|
|
to internally defined general entities. Instead these references are
|
|
passed to the default handler.</p>
|
|
|
|
<p>See also <code><a
|
|
href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetDefaultHandlerExpand">
|
|
void XMLCALL
|
|
XML_SetDefaultHandlerExpand(XML_Parser p,
|
|
XML_DefaultHandler hndl)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_DefaultHandler)(void *userData,
|
|
const XML_Char *s,
|
|
int len);
|
|
</pre>
|
|
<p>This sets a default handler, but doesn't inhibit the expansion of
|
|
internal entity references. The entity reference will not be passed
|
|
to the default handler.</p>
|
|
|
|
<p>See also <code><a
|
|
href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetExternalEntityRefHandler">
|
|
void XMLCALL
|
|
XML_SetExternalEntityRefHandler(XML_Parser p,
|
|
XML_ExternalEntityRefHandler hndl)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef int
|
|
(XMLCALL *XML_ExternalEntityRefHandler)(XML_Parser p,
|
|
const XML_Char *context,
|
|
const XML_Char *base,
|
|
const XML_Char *systemId,
|
|
const XML_Char *publicId);
|
|
</pre>
|
|
<p>Set an external entity reference handler. This handler is also
|
|
called for processing an external DTD subset if parameter entity parsing
|
|
is in effect. (See <a href="#XML_SetParamEntityParsing">
|
|
<code>XML_SetParamEntityParsing</code></a>.)</p>
|
|
|
|
<p>The <code>context</code> parameter specifies the parsing context in
|
|
the format expected by the <code>context</code> argument to <code><a
|
|
href="#XML_ExternalEntityParserCreate"
|
|
>XML_ExternalEntityParserCreate</a></code>. <code>code</code> is
|
|
valid only until the handler returns, so if the referenced entity is
|
|
to be parsed later, it must be copied. <code>context</code> is NULL
|
|
only when the entity is a parameter entity, which is how one can
|
|
differentiate between general and parameter entities.</p>
|
|
|
|
<p>The <code>base</code> parameter is the base to use for relative
|
|
system identifiers. It is set by <code><a
|
|
href="#XML_SetBase">XML_SetBase</a></code> and may be NULL. The
|
|
<code>publicId</code> parameter is the public id given in the entity
|
|
declaration and may be NULL. <code>systemId</code> is the system
|
|
identifier specified in the entity declaration and is never NULL.</p>
|
|
|
|
<p>There are a couple of ways in which this handler differs from
|
|
others. First, this handler returns a status indicator (an
|
|
integer). <code>XML_STATUS_OK</code> should be returned for successful
|
|
handling of the external entity reference. Returning
|
|
<code>XML_STATUS_ERROR</code> indicates failure, and causes the
|
|
calling parser to return an
|
|
<code>XML_ERROR_EXTERNAL_ENTITY_HANDLING</code> error.</p>
|
|
|
|
<p>Second, instead of having the user data as its first argument, it
|
|
receives the parser that encountered the entity reference. This, along
|
|
with the context parameter, may be used as arguments to a call to
|
|
<code><a href= "#XML_ExternalEntityParserCreate"
|
|
>XML_ExternalEntityParserCreate</a></code>. Using the returned
|
|
parser, the body of the external entity can be recursively parsed.</p>
|
|
|
|
<p>Since this handler may be called recursively, it should not be saving
|
|
information into global or static variables.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_SetExternalEntityRefHandlerArg">
|
|
void XMLCALL
|
|
XML_SetExternalEntityRefHandlerArg(XML_Parser p,
|
|
void *arg)
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>Set the argument passed to the ExternalEntityRefHandler. If
|
|
<code>arg</code> is not NULL, it is the new value passed to the
|
|
handler set using <code><a href="#XML_SetExternalEntityRefHandler"
|
|
>XML_SetExternalEntityRefHandler</a></code>; if <code>arg</code> is
|
|
NULL, the argument passed to the handler function will be the parser
|
|
object itself.</p>
|
|
|
|
<p><strong>Note:</strong>
|
|
The type of <code>arg</code> and the type of the first argument to the
|
|
ExternalEntityRefHandler do not match. This function takes a
|
|
<code>void *</code> to be passed to the handler, while the handler
|
|
accepts an <code>XML_Parser</code>. This is a historical accident,
|
|
but will not be corrected before Expat 2.0 (at the earliest) to avoid
|
|
causing compiler warnings for code that's known to work with this
|
|
API. It is the responsibility of the application code to know the
|
|
actual type of the argument passed to the handler and to manage it
|
|
properly.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetSkippedEntityHandler">
|
|
void XMLCALL
|
|
XML_SetSkippedEntityHandler(XML_Parser p,
|
|
XML_SkippedEntityHandler handler)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_SkippedEntityHandler)(void *userData,
|
|
const XML_Char *entityName,
|
|
int is_parameter_entity);
|
|
</pre>
|
|
<p>Set a skipped entity handler. This is called in two situations:</p>
|
|
<ol>
|
|
<li>An entity reference is encountered for which no declaration
|
|
has been read <em>and</em> this is not an error.</li>
|
|
<li>An internal entity reference is read, but not expanded, because
|
|
<a href="#XML_SetDefaultHandler"><code>XML_SetDefaultHandler</code></a>
|
|
has been called.</li>
|
|
</ol>
|
|
<p>The <code>is_parameter_entity</code> argument will be non-zero for
|
|
a parameter entity and zero for a general entity.</p> <p>Note: skipped
|
|
parameter entities in declarations and skipped general entities in
|
|
attribute values cannot be reported, because the event would be out of
|
|
sync with the reporting of the declarations or attribute values</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetUnknownEncodingHandler">
|
|
void XMLCALL
|
|
XML_SetUnknownEncodingHandler(XML_Parser p,
|
|
XML_UnknownEncodingHandler enchandler,
|
|
void *encodingHandlerData)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef int
|
|
(XMLCALL *XML_UnknownEncodingHandler)(void *encodingHandlerData,
|
|
const XML_Char *name,
|
|
XML_Encoding *info);
|
|
|
|
typedef struct {
|
|
int map[256];
|
|
void *data;
|
|
int (XMLCALL *convert)(void *data, const char *s);
|
|
void (XMLCALL *release)(void *data);
|
|
} XML_Encoding;
|
|
</pre>
|
|
<p>Set a handler to deal with encodings other than the <a
|
|
href="#builtin_encodings">built in set</a>. This should be done before
|
|
<code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a href=
|
|
"#XML_ParseBuffer" >XML_ParseBuffer</a></code> have been called on the
|
|
given parser.</p> <p>If the handler knows how to deal with an encoding
|
|
with the given name, it should fill in the <code>info</code> data
|
|
structure and return <code>XML_STATUS_OK</code>. Otherwise it
|
|
should return <code>XML_STATUS_ERROR</code>. The handler will be called
|
|
at most once per parsed (external) entity. The optional application
|
|
data pointer <code>encodingHandlerData</code> will be passed back to
|
|
the handler.</p>
|
|
|
|
<p>The map array contains information for every possible possible leading
|
|
byte in a byte sequence. If the corresponding value is >= 0, then it's
|
|
a single byte sequence and the byte encodes that Unicode value. If the
|
|
value is -1, then that byte is invalid as the initial byte in a sequence.
|
|
If the value is -n, where n is an integer > 1, then n is the number of
|
|
bytes in the sequence and the actual conversion is accomplished by a
|
|
call to the function pointed at by convert. This function may return -1
|
|
if the sequence itself is invalid. The convert pointer may be null if
|
|
there are only single byte codes. The data parameter passed to the convert
|
|
function is the data pointer from <code>XML_Encoding</code>. The
|
|
string s is <em>NOT</em> nul-terminated and points at the sequence of
|
|
bytes to be converted.</p>
|
|
|
|
<p>The function pointed at by <code>release</code> is called by the
|
|
parser when it is finished with the encoding. It may be NULL.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetStartNamespaceDeclHandler">
|
|
void XMLCALL
|
|
XML_SetStartNamespaceDeclHandler(XML_Parser p,
|
|
XML_StartNamespaceDeclHandler start);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_StartNamespaceDeclHandler)(void *userData,
|
|
const XML_Char *prefix,
|
|
const XML_Char *uri);
|
|
</pre>
|
|
<p>Set a handler to be called when a namespace is declared. Namespace
|
|
declarations occur inside start tags. But the namespace declaration start
|
|
handler is called before the start tag handler for each namespace declared
|
|
in that start tag.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetEndNamespaceDeclHandler">
|
|
void XMLCALL
|
|
XML_SetEndNamespaceDeclHandler(XML_Parser p,
|
|
XML_EndNamespaceDeclHandler end);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_EndNamespaceDeclHandler)(void *userData,
|
|
const XML_Char *prefix);
|
|
</pre>
|
|
<p>Set a handler to be called when leaving the scope of a namespace
|
|
declaration. This will be called, for each namespace declaration,
|
|
after the handler for the end tag of the element in which the
|
|
namespace was declared.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetNamespaceDeclHandler">
|
|
void XMLCALL
|
|
XML_SetNamespaceDeclHandler(XML_Parser p,
|
|
XML_StartNamespaceDeclHandler start,
|
|
XML_EndNamespaceDeclHandler end)
|
|
</pre>
|
|
<p>Sets both namespace declaration handlers with a single call.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetXmlDeclHandler">
|
|
void XMLCALL
|
|
XML_SetXmlDeclHandler(XML_Parser p,
|
|
XML_XmlDeclHandler xmldecl);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_XmlDeclHandler)(void *userData,
|
|
const XML_Char *version,
|
|
const XML_Char *encoding,
|
|
int standalone);
|
|
</pre>
|
|
<p>Sets a handler that is called for XML declarations and also for
|
|
text declarations discovered in external entities. The way to
|
|
distinguish is that the <code>version</code> parameter will be NULL
|
|
for text declarations. The <code>encoding</code> parameter may be NULL
|
|
for an XML declaration. The <code>standalone</code> argument will
|
|
contain -1, 0, or 1 indicating respectively that there was no
|
|
standalone parameter in the declaration, that it was given as no, or
|
|
that it was given as yes.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetStartDoctypeDeclHandler">
|
|
void XMLCALL
|
|
XML_SetStartDoctypeDeclHandler(XML_Parser p,
|
|
XML_StartDoctypeDeclHandler start);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_StartDoctypeDeclHandler)(void *userData,
|
|
const XML_Char *doctypeName,
|
|
const XML_Char *sysid,
|
|
const XML_Char *pubid,
|
|
int has_internal_subset);
|
|
</pre>
|
|
<p>Set a handler that is called at the start of a DOCTYPE declaration,
|
|
before any external or internal subset is parsed. Both <code>sysid</code>
|
|
and <code>pubid</code> may be NULL. The <code>has_internal_subset</code>
|
|
will be non-zero if the DOCTYPE declaration has an internal subset.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetEndDoctypeDeclHandler">
|
|
void XMLCALL
|
|
XML_SetEndDoctypeDeclHandler(XML_Parser p,
|
|
XML_EndDoctypeDeclHandler end);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_EndDoctypeDeclHandler)(void *userData);
|
|
</pre>
|
|
<p>Set a handler that is called at the end of a DOCTYPE declaration,
|
|
after parsing any external subset.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetDoctypeDeclHandler">
|
|
void XMLCALL
|
|
XML_SetDoctypeDeclHandler(XML_Parser p,
|
|
XML_StartDoctypeDeclHandler start,
|
|
XML_EndDoctypeDeclHandler end);
|
|
</pre>
|
|
<p>Set both doctype handlers with one call.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetElementDeclHandler">
|
|
void XMLCALL
|
|
XML_SetElementDeclHandler(XML_Parser p,
|
|
XML_ElementDeclHandler eldecl);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_ElementDeclHandler)(void *userData,
|
|
const XML_Char *name,
|
|
XML_Content *model);
|
|
</pre>
|
|
<pre class="signature">
|
|
enum XML_Content_Type {
|
|
XML_CTYPE_EMPTY = 1,
|
|
XML_CTYPE_ANY,
|
|
XML_CTYPE_MIXED,
|
|
XML_CTYPE_NAME,
|
|
XML_CTYPE_CHOICE,
|
|
XML_CTYPE_SEQ
|
|
};
|
|
|
|
enum XML_Content_Quant {
|
|
XML_CQUANT_NONE,
|
|
XML_CQUANT_OPT,
|
|
XML_CQUANT_REP,
|
|
XML_CQUANT_PLUS
|
|
};
|
|
|
|
typedef struct XML_cp XML_Content;
|
|
|
|
struct XML_cp {
|
|
enum XML_Content_Type type;
|
|
enum XML_Content_Quant quant;
|
|
const XML_Char * name;
|
|
unsigned int numchildren;
|
|
XML_Content * children;
|
|
};
|
|
</pre>
|
|
<p>Sets a handler for element declarations in a DTD. The handler gets
|
|
called with the name of the element in the declaration and a pointer
|
|
to a structure that contains the element model. It is the
|
|
application's responsibility to free this data structure using
|
|
<code><a href="#XML_FreeContentModel"
|
|
>XML_FreeContentModel</a></code>.</p>
|
|
|
|
<p>The <code>model</code> argument is the root of a tree of
|
|
<code>XML_Content</code> nodes. If <code>type</code> equals
|
|
<code>XML_CTYPE_EMPTY</code> or <code>XML_CTYPE_ANY</code>, then
|
|
<code>quant</code> will be <code>XML_CQUANT_NONE</code>, and the other
|
|
fields will be zero or NULL. If <code>type</code> is
|
|
<code>XML_CTYPE_MIXED</code>, then <code>quant</code> will be
|
|
<code>XML_CQUANT_NONE</code> or <code>XML_CQUANT_REP</code> and
|
|
<code>numchildren</code> will contain the number of elements that are
|
|
allowed to be mixed in and <code>children</code> points to an array of
|
|
<code>XML_Content</code> structures that will all have type
|
|
XML_CTYPE_NAME with no quantification. Only the root node can be type
|
|
<code>XML_CTYPE_EMPTY</code>, <code>XML_CTYPE_ANY</code>, or
|
|
<code>XML_CTYPE_MIXED</code>.</p>
|
|
|
|
<p>For type <code>XML_CTYPE_NAME</code>, the <code>name</code> field
|
|
points to the name and the <code>numchildren</code> and
|
|
<code>children</code> fields will be zero and NULL. The
|
|
<code>quant</code> field will indicate any quantifiers placed on the
|
|
name.</p>
|
|
|
|
<p>Types <code>XML_CTYPE_CHOICE</code> and <code>XML_CTYPE_SEQ</code>
|
|
indicate a choice or sequence respectively. The
|
|
<code>numchildren</code> field indicates how many nodes in the choice
|
|
or sequence and <code>children</code> points to the nodes.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetAttlistDeclHandler">
|
|
void XMLCALL
|
|
XML_SetAttlistDeclHandler(XML_Parser p,
|
|
XML_AttlistDeclHandler attdecl);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_AttlistDeclHandler)(void *userData,
|
|
const XML_Char *elname,
|
|
const XML_Char *attname,
|
|
const XML_Char *att_type,
|
|
const XML_Char *dflt,
|
|
int isrequired);
|
|
</pre>
|
|
<p>Set a handler for attlist declarations in the DTD. This handler is
|
|
called for <em>each</em> attribute. So a single attlist declaration
|
|
with multiple attributes declared will generate multiple calls to this
|
|
handler. The <code>elname</code> parameter returns the name of the
|
|
element for which the attribute is being declared. The attribute name
|
|
is in the <code>attname</code> parameter. The attribute type is in the
|
|
<code>att_type</code> parameter. It is the string representing the
|
|
type in the declaration with whitespace removed.</p>
|
|
|
|
<p>The <code>dflt</code> parameter holds the default value. It will be
|
|
NULL in the case of "#IMPLIED" or "#REQUIRED" attributes. You can
|
|
distinguish these two cases by checking the <code>isrequired</code>
|
|
parameter, which will be true in the case of "#REQUIRED" attributes.
|
|
Attributes which are "#FIXED" will have also have a true
|
|
<code>isrequired</code>, but they will have the non-NULL fixed value
|
|
in the <code>dflt</code> parameter.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetEntityDeclHandler">
|
|
void XMLCALL
|
|
XML_SetEntityDeclHandler(XML_Parser p,
|
|
XML_EntityDeclHandler handler);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_EntityDeclHandler)(void *userData,
|
|
const XML_Char *entityName,
|
|
int is_parameter_entity,
|
|
const XML_Char *value,
|
|
int value_length,
|
|
const XML_Char *base,
|
|
const XML_Char *systemId,
|
|
const XML_Char *publicId,
|
|
const XML_Char *notationName);
|
|
</pre>
|
|
<p>Sets a handler that will be called for all entity declarations.
|
|
The <code>is_parameter_entity</code> argument will be non-zero in the
|
|
case of parameter entities and zero otherwise.</p>
|
|
|
|
<p>For internal entities (<code><!ENTITY foo "bar"></code>),
|
|
<code>value</code> will be non-NULL and <code>systemId</code>,
|
|
<code>publicId</code>, and <code>notationName</code> will all be NULL.
|
|
The value string is <em>not</em> NULL terminated; the length is
|
|
provided in the <code>value_length</code> parameter. Do not use
|
|
<code>value_length</code> to test for internal entities, since it is
|
|
legal to have zero-length values. Instead check for whether or not
|
|
<code>value</code> is NULL.</p> <p>The <code>notationName</code>
|
|
argument will have a non-NULL value only for unparsed entity
|
|
declarations.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetUnparsedEntityDeclHandler">
|
|
void XMLCALL
|
|
XML_SetUnparsedEntityDeclHandler(XML_Parser p,
|
|
XML_UnparsedEntityDeclHandler h)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_UnparsedEntityDeclHandler)(void *userData,
|
|
const XML_Char *entityName,
|
|
const XML_Char *base,
|
|
const XML_Char *systemId,
|
|
const XML_Char *publicId,
|
|
const XML_Char *notationName);
|
|
</pre>
|
|
<p>Set a handler that receives declarations of unparsed entities. These
|
|
are entity declarations that have a notation (NDATA) field:</p>
|
|
|
|
<div id="eg"><pre>
|
|
<!ENTITY logo SYSTEM "images/logo.gif" NDATA gif>
|
|
</pre></div>
|
|
<p>This handler is obsolete and is provided for backwards
|
|
compatibility. Use instead <a href= "#XML_SetEntityDeclHandler"
|
|
>XML_SetEntityDeclHandler</a>.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetNotationDeclHandler">
|
|
void XMLCALL
|
|
XML_SetNotationDeclHandler(XML_Parser p,
|
|
XML_NotationDeclHandler h)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef void
|
|
(XMLCALL *XML_NotationDeclHandler)(void *userData,
|
|
const XML_Char *notationName,
|
|
const XML_Char *base,
|
|
const XML_Char *systemId,
|
|
const XML_Char *publicId);
|
|
</pre>
|
|
<p>Set a handler that receives notation declarations.</p>
|
|
</div>
|
|
|
|
<div class="handler">
|
|
<pre class="setter" id="XML_SetNotStandaloneHandler">
|
|
void XMLCALL
|
|
XML_SetNotStandaloneHandler(XML_Parser p,
|
|
XML_NotStandaloneHandler h)
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef int
|
|
(XMLCALL *XML_NotStandaloneHandler)(void *userData);
|
|
</pre>
|
|
<p>Set a handler that is called if the document is not "standalone".
|
|
This happens when there is an external subset or a reference to a
|
|
parameter entity, but does not have standalone set to "yes" in an XML
|
|
declaration. If this handler returns <code>XML_STATUS_ERROR</code>,
|
|
then the parser will throw an <code>XML_ERROR_NOT_STANDALONE</code>
|
|
error.</p>
|
|
</div>
|
|
|
|
<h3><a name="position">Parse position and error reporting functions</a></h3>
|
|
|
|
<p>These are the functions you'll want to call when the parse
|
|
functions return <code>XML_STATUS_ERROR</code> (a parse error has
|
|
occurred), although the position reporting functions are useful outside
|
|
of errors. The position reported is the byte position (in the original
|
|
document or entity encoding) of the first of the sequence of
|
|
characters that generated the current event (or the error that caused
|
|
the parse functions to return <code>XML_STATUS_ERROR</code>.) The
|
|
exceptions are callbacks trigged by declarations in the document
|
|
prologue, in which case they exact position reported is somewhere in the
|
|
relevant markup, but not necessarily as meaningful as for other
|
|
events.</p>
|
|
|
|
<p>The position reporting functions are accurate only outside of the
|
|
DTD. In other words, they usually return bogus information when
|
|
called from within a DTD declaration handler.</p>
|
|
|
|
<pre class="fcndec" id="XML_GetErrorCode">
|
|
enum XML_Error XMLCALL
|
|
XML_GetErrorCode(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return what type of error has occurred.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ErrorString">
|
|
const XML_LChar * XMLCALL
|
|
XML_ErrorString(enum XML_Error code);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return a string describing the error corresponding to code.
|
|
The code should be one of the enums that can be returned from
|
|
<code><a href= "#XML_GetErrorCode" >XML_GetErrorCode</a></code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetCurrentByteIndex">
|
|
XML_Index XMLCALL
|
|
XML_GetCurrentByteIndex(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the byte offset of the position. This always corresponds to
|
|
the values returned by <code><a href= "#XML_GetCurrentLineNumber"
|
|
>XML_GetCurrentLineNumber</a></code> and <code><a href=
|
|
"#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetCurrentLineNumber">
|
|
XML_Size XMLCALL
|
|
XML_GetCurrentLineNumber(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the line number of the position. The first line is reported as
|
|
<code>1</code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetCurrentColumnNumber">
|
|
XML_Size XMLCALL
|
|
XML_GetCurrentColumnNumber(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the offset, from the beginning of the current line, of
|
|
the position.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetCurrentByteCount">
|
|
int XMLCALL
|
|
XML_GetCurrentByteCount(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the number of bytes in the current event. Returns
|
|
<code>0</code> if the event is inside a reference to an internal
|
|
entity and for the end-tag event for empty element tags (the later can
|
|
be used to distinguish empty-element tags from empty elements using
|
|
separate start and end tags).
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetInputContext">
|
|
const char * XMLCALL
|
|
XML_GetInputContext(XML_Parser p,
|
|
int *offset,
|
|
int *size);
|
|
</pre>
|
|
<div class="fcndef">
|
|
|
|
<p>Returns the parser's input buffer, sets the integer pointed at by
|
|
<code>offset</code> to the offset within this buffer of the current
|
|
parse position, and set the integer pointed at by <code>size</code> to
|
|
the size of the returned buffer.</p>
|
|
|
|
<p>This should only be called from within a handler during an active
|
|
parse and the returned buffer should only be referred to from within
|
|
the handler that made the call. This input buffer contains the
|
|
untranslated bytes of the input.</p>
|
|
|
|
<p>Only a limited amount of context is kept, so if the event
|
|
triggering a call spans over a very large amount of input, the actual
|
|
parse position may be before the beginning of the buffer.</p>
|
|
|
|
<p>If <code>XML_CONTEXT_BYTES</code> is not defined, this will always
|
|
return NULL.</p>
|
|
</div>
|
|
|
|
<h3><a name="miscellaneous">Miscellaneous functions</a></h3>
|
|
|
|
<p>The functions in this section either obtain state information from
|
|
the parser or can be used to dynamicly set parser options.</p>
|
|
|
|
<pre class="fcndec" id="XML_SetUserData">
|
|
void XMLCALL
|
|
XML_SetUserData(XML_Parser p,
|
|
void *userData);
|
|
</pre>
|
|
<div class="fcndef">
|
|
This sets the user data pointer that gets passed to handlers. It
|
|
overwrites any previous value for this pointer. Note that the
|
|
application is responsible for freeing the memory associated with
|
|
<code>userData</code> when it is finished with the parser. So if you
|
|
call this when there's already a pointer there, and you haven't freed
|
|
the memory associated with it, then you've probably just leaked
|
|
memory.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetUserData">
|
|
void * XMLCALL
|
|
XML_GetUserData(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
This returns the user data pointer that gets passed to handlers.
|
|
It is actually implemented as a macro.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_UseParserAsHandlerArg">
|
|
void XMLCALL
|
|
XML_UseParserAsHandlerArg(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
After this is called, handlers receive the parser in their
|
|
<code>userData</code> arguments. The user data can still be obtained
|
|
using the <code><a href= "#XML_GetUserData"
|
|
>XML_GetUserData</a></code> function.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_SetBase">
|
|
enum XML_Status XMLCALL
|
|
XML_SetBase(XML_Parser p,
|
|
const XML_Char *base);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Set the base to be used for resolving relative URIs in system
|
|
identifiers. The return value is <code>XML_STATUS_ERROR</code> if
|
|
there's no memory to store base, otherwise it's
|
|
<code>XML_STATUS_OK</code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetBase">
|
|
const XML_Char * XMLCALL
|
|
XML_GetBase(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the base for resolving relative URIs.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetSpecifiedAttributeCount">
|
|
int XMLCALL
|
|
XML_GetSpecifiedAttributeCount(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
When attributes are reported to the start handler in the atts vector,
|
|
attributes that were explicitly set in the element occur before any
|
|
attributes that receive their value from default information in an
|
|
ATTLIST declaration. This function returns the number of attributes
|
|
that were explicitly set times two, thus giving the offset in the
|
|
<code>atts</code> array passed to the start tag handler of the first
|
|
attribute set due to defaults. It supplies information for the last
|
|
call to a start handler. If called inside a start handler, then that
|
|
means the current call.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetIdAttributeIndex">
|
|
int XMLCALL
|
|
XML_GetIdAttributeIndex(XML_Parser p);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Returns the index of the ID attribute passed in the atts array in the
|
|
last call to <code><a href= "#XML_StartElementHandler"
|
|
>XML_StartElementHandler</a></code>, or -1 if there is no ID
|
|
attribute. If called inside a start handler, then that means the
|
|
current call.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetAttributeInfo">
|
|
const XML_AttrInfo * XMLCALL
|
|
XML_GetAttributeInfo(XML_Parser parser);
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef struct {
|
|
XML_Index nameStart; /* Offset to beginning of the attribute name. */
|
|
XML_Index nameEnd; /* Offset after the attribute name's last byte. */
|
|
XML_Index valueStart; /* Offset to beginning of the attribute value. */
|
|
XML_Index valueEnd; /* Offset after the attribute value's last byte. */
|
|
} XML_AttrInfo;
|
|
</pre>
|
|
<div class="fcndef">
|
|
Returns an array of <code>XML_AttrInfo</code> structures for the
|
|
attribute/value pairs passed in the last call to the
|
|
<code>XML_StartElementHandler</code> that were specified
|
|
in the start-tag rather than defaulted. Each attribute/value pair counts
|
|
as 1; thus the number of entries in the array is
|
|
<code>XML_GetSpecifiedAttributeCount(parser) / 2</code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_SetEncoding">
|
|
enum XML_Status XMLCALL
|
|
XML_SetEncoding(XML_Parser p,
|
|
const XML_Char *encoding);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Set the encoding to be used by the parser. It is equivalent to
|
|
passing a non-null encoding argument to the parser creation functions.
|
|
It must not be called after <code><a href= "#XML_Parse"
|
|
>XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer"
|
|
>XML_ParseBuffer</a></code> have been called on the given parser.
|
|
Returns <code>XML_STATUS_OK</code> on success or
|
|
<code>XML_STATUS_ERROR</code> on error.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_SetParamEntityParsing">
|
|
int XMLCALL
|
|
XML_SetParamEntityParsing(XML_Parser p,
|
|
enum XML_ParamEntityParsing code);
|
|
</pre>
|
|
<div class="fcndef">
|
|
This enables parsing of parameter entities, including the external
|
|
parameter entity that is the external DTD subset, according to
|
|
<code>code</code>.
|
|
The choices for <code>code</code> are:
|
|
<ul>
|
|
<li><code>XML_PARAM_ENTITY_PARSING_NEVER</code></li>
|
|
<li><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></li>
|
|
<li><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></li>
|
|
</ul>
|
|
<b>Note:</b> If <code>XML_SetParamEntityParsing</code> is called after
|
|
<code>XML_Parse</code> or <code>XML_ParseBuffer</code>, then it has
|
|
no effect and will always return 0.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_SetHashSalt">
|
|
int XMLCALL
|
|
XML_SetHashSalt(XML_Parser p,
|
|
unsigned long hash_salt);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Sets the hash salt to use for internal hash calculations.
|
|
Helps in preventing DoS attacks based on predicting hash
|
|
function behavior. In order to have an effect this must be called
|
|
before parsing has started. Returns 1 if successful, 0 when called
|
|
after <code>XML_Parse</code> or <code>XML_ParseBuffer</code>.
|
|
<p><b>Note:</b> This call is optional, as the parser will auto-generate a new
|
|
random salt value if no value has been set at the start of parsing.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_UseForeignDTD">
|
|
enum XML_Error XMLCALL
|
|
XML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD);
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>This function allows an application to provide an external subset
|
|
for the document type declaration for documents which do not specify
|
|
an external subset of their own. For documents which specify an
|
|
external subset in their DOCTYPE declaration, the application-provided
|
|
subset will be ignored. If the document does not contain a DOCTYPE
|
|
declaration at all and <code>useDTD</code> is true, the
|
|
application-provided subset will be parsed, but the
|
|
<code>startDoctypeDeclHandler</code> and
|
|
<code>endDoctypeDeclHandler</code> functions, if set, will not be
|
|
called. The setting of parameter entity parsing, controlled using
|
|
<code><a href= "#XML_SetParamEntityParsing"
|
|
>XML_SetParamEntityParsing</a></code>, will be honored.</p>
|
|
|
|
<p>The application-provided external subset is read by calling the
|
|
external entity reference handler set via <code><a href=
|
|
"#XML_SetExternalEntityRefHandler"
|
|
>XML_SetExternalEntityRefHandler</a></code> with both
|
|
<code>publicId</code> and <code>systemId</code> set to NULL.</p>
|
|
|
|
<p>If this function is called after parsing has begun, it returns
|
|
<code>XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING</code> and ignores
|
|
<code>useDTD</code>. If called when Expat has been compiled without
|
|
DTD support, it returns
|
|
<code>XML_ERROR_FEATURE_REQUIRES_XML_DTD</code>. Otherwise, it
|
|
returns <code>XML_ERROR_NONE</code>.</p>
|
|
|
|
<p><b>Note:</b> For the purpose of checking WFC: Entity Declared, passing
|
|
<code>useDTD == XML_TRUE</code> will make the parser behave as if
|
|
the document had a DTD with an external subset. This holds true even if
|
|
the external entity reference handler returns without action.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_SetReturnNSTriplet">
|
|
void XMLCALL
|
|
XML_SetReturnNSTriplet(XML_Parser parser,
|
|
int do_nst);
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>
|
|
This function only has an effect when using a parser created with
|
|
<code><a href= "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>,
|
|
i.e. when namespace processing is in effect. The <code>do_nst</code>
|
|
sets whether or not prefixes are returned with names qualified with a
|
|
namespace prefix. If this function is called with <code>do_nst</code>
|
|
non-zero, then afterwards namespace qualified names (that is qualified
|
|
with a prefix as opposed to belonging to a default namespace) are
|
|
returned as a triplet with the three parts separated by the namespace
|
|
separator specified when the parser was created. The order of
|
|
returned parts is URI, local name, and prefix.</p> <p>If
|
|
<code>do_nst</code> is zero, then namespaces are reported in the
|
|
default manner, URI then local_name separated by the namespace
|
|
separator.</p>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_DefaultCurrent">
|
|
void XMLCALL
|
|
XML_DefaultCurrent(XML_Parser parser);
|
|
</pre>
|
|
<div class="fcndef">
|
|
This can be called within a handler for a start element, end element,
|
|
processing instruction or character data. It causes the corresponding
|
|
markup to be passed to the default handler set by <code><a
|
|
href="#XML_SetDefaultHandler" >XML_SetDefaultHandler</a></code> or
|
|
<code><a href="#XML_SetDefaultHandlerExpand"
|
|
>XML_SetDefaultHandlerExpand</a></code>. It does nothing if there is
|
|
not a default handler.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ExpatVersion">
|
|
XML_LChar * XMLCALL
|
|
XML_ExpatVersion();
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the library version as a string (e.g. <code>"expat_1.95.1"</code>).
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_ExpatVersionInfo">
|
|
struct XML_Expat_Version XMLCALL
|
|
XML_ExpatVersionInfo();
|
|
</pre>
|
|
<pre class="signature">
|
|
typedef struct {
|
|
int major;
|
|
int minor;
|
|
int micro;
|
|
} XML_Expat_Version;
|
|
</pre>
|
|
<div class="fcndef">
|
|
Return the library version information as a structure.
|
|
Some macros are also defined that support compile-time tests of the
|
|
library version:
|
|
<ul>
|
|
<li><code>XML_MAJOR_VERSION</code></li>
|
|
<li><code>XML_MINOR_VERSION</code></li>
|
|
<li><code>XML_MICRO_VERSION</code></li>
|
|
</ul>
|
|
Testing these constants is currently the best way to determine if
|
|
particular parts of the Expat API are available.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_GetFeatureList">
|
|
const XML_Feature * XMLCALL
|
|
XML_GetFeatureList();
|
|
</pre>
|
|
<pre class="signature">
|
|
enum XML_FeatureEnum {
|
|
XML_FEATURE_END = 0,
|
|
XML_FEATURE_UNICODE,
|
|
XML_FEATURE_UNICODE_WCHAR_T,
|
|
XML_FEATURE_DTD,
|
|
XML_FEATURE_CONTEXT_BYTES,
|
|
XML_FEATURE_MIN_SIZE,
|
|
XML_FEATURE_SIZEOF_XML_CHAR,
|
|
XML_FEATURE_SIZEOF_XML_LCHAR,
|
|
XML_FEATURE_NS,
|
|
XML_FEATURE_LARGE_SIZE
|
|
};
|
|
|
|
typedef struct {
|
|
enum XML_FeatureEnum feature;
|
|
XML_LChar *name;
|
|
long int value;
|
|
} XML_Feature;
|
|
</pre>
|
|
<div class="fcndef">
|
|
<p>Returns a list of "feature" records, providing details on how
|
|
Expat was configured at compile time. Most applications should not
|
|
need to worry about this, but this information is otherwise not
|
|
available from Expat. This function allows code that does need to
|
|
check these features to do so at runtime.</p>
|
|
|
|
<p>The return value is an array of <code>XML_Feature</code>,
|
|
terminated by a record with a <code>feature</code> of
|
|
<code>XML_FEATURE_END</code> and <code>name</code> of NULL,
|
|
identifying the feature-test macros Expat was compiled with. Since an
|
|
application that requires this kind of information needs to determine
|
|
the type of character the <code>name</code> points to, records for the
|
|
<code>XML_FEATURE_SIZEOF_XML_CHAR</code> and
|
|
<code>XML_FEATURE_SIZEOF_XML_LCHAR</code> will be located at the
|
|
beginning of the list, followed by <code>XML_FEATURE_UNICODE</code>
|
|
and <code>XML_FEATURE_UNICODE_WCHAR_T</code>, if they are present at
|
|
all.</p>
|
|
|
|
<p>Some features have an associated value. If there isn't an
|
|
associated value, the <code>value</code> field is set to 0. At this
|
|
time, the following features have been defined to have values:</p>
|
|
|
|
<dl>
|
|
<dt><code>XML_FEATURE_SIZEOF_XML_CHAR</code></dt>
|
|
<dd>The number of bytes occupied by one <code>XML_Char</code>
|
|
character.</dd>
|
|
<dt><code>XML_FEATURE_SIZEOF_XML_LCHAR</code></dt>
|
|
<dd>The number of bytes occupied by one <code>XML_LChar</code>
|
|
character.</dd>
|
|
<dt><code>XML_FEATURE_CONTEXT_BYTES</code></dt>
|
|
<dd>The maximum number of characters of context which can be
|
|
reported by <code><a href= "#XML_GetInputContext"
|
|
>XML_GetInputContext</a></code>.</dd>
|
|
</dl>
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_FreeContentModel">
|
|
void XMLCALL
|
|
XML_FreeContentModel(XML_Parser parser, XML_Content *model);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Function to deallocate the <code>model</code> argument passed to the
|
|
<code>XML_ElementDeclHandler</code> callback set using <code><a
|
|
href="#XML_SetElementDeclHandler" >XML_ElementDeclHandler</a></code>.
|
|
This function should not be used for any other purpose.
|
|
</div>
|
|
|
|
<p>The following functions allow external code to share the memory
|
|
allocator an <code>XML_Parser</code> has been configured to use. This
|
|
is especially useful for third-party libraries that interact with a
|
|
parser object created by application code, or heavily layered
|
|
applications. This can be essential when using dynamically loaded
|
|
libraries which use different C standard libraries (this can happen on
|
|
Windows, at least).</p>
|
|
|
|
<pre class="fcndec" id="XML_MemMalloc">
|
|
void * XMLCALL
|
|
XML_MemMalloc(XML_Parser parser, size_t size);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Allocate <code>size</code> bytes of memory using the allocator the
|
|
<code>parser</code> object has been configured to use. Returns a
|
|
pointer to the memory or NULL on failure. Memory allocated in this
|
|
way must be freed using <code><a href="#XML_MemFree"
|
|
>XML_MemFree</a></code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_MemRealloc">
|
|
void * XMLCALL
|
|
XML_MemRealloc(XML_Parser parser, void *ptr, size_t size);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Allocate <code>size</code> bytes of memory using the allocator the
|
|
<code>parser</code> object has been configured to use.
|
|
<code>ptr</code> must point to a block of memory allocated by <code><a
|
|
href="#XML_MemMalloc" >XML_MemMalloc</a></code> or
|
|
<code>XML_MemRealloc</code>, or be NULL. This function tries to
|
|
expand the block pointed to by <code>ptr</code> if possible. Returns
|
|
a pointer to the memory or NULL on failure. On success, the original
|
|
block has either been expanded or freed. On failure, the original
|
|
block has not been freed; the caller is responsible for freeing the
|
|
original block. Memory allocated in this way must be freed using
|
|
<code><a href="#XML_MemFree"
|
|
>XML_MemFree</a></code>.
|
|
</div>
|
|
|
|
<pre class="fcndec" id="XML_MemFree">
|
|
void XMLCALL
|
|
XML_MemFree(XML_Parser parser, void *ptr);
|
|
</pre>
|
|
<div class="fcndef">
|
|
Free a block of memory pointed to by <code>ptr</code>. The block must
|
|
have been allocated by <code><a href="#XML_MemMalloc"
|
|
>XML_MemMalloc</a></code> or <code>XML_MemRealloc</code>, or be NULL.
|
|
</div>
|
|
|
|
<hr />
|
|
<p><a href="http://validator.w3.org/check/referer"><img
|
|
src="valid-xhtml10.png" alt="Valid XHTML 1.0!"
|
|
height="31" width="88" class="noborder" /></a></p>
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|
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