915 lines
78 KiB
HTML
915 lines
78 KiB
HTML
<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
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<title>Loading document</title>
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<link rel="stylesheet" href="../pugixml.css" type="text/css">
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<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
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<link rel="home" href="../manual.html" title="pugixml 1.5">
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<link rel="up" href="../manual.html" title="pugixml 1.5">
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<link rel="prev" href="dom.html" title="Document object model">
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<link rel="next" href="access.html" title="Accessing document data">
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</head>
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<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
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<table width="100%"><tr>
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<td>
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<a href="http://pugixml.org/">pugixml 1.5</a> manual |
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<a href="../manual.html">Overview</a> |
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<a href="install.html">Installation</a> |
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Document:
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<a href="dom.html">Object model</a> · <b>Loading</b> · <a href="access.html">Accessing</a> · <a href="modify.html">Modifying</a> · <a href="saving.html">Saving</a> |
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<a href="xpath.html">XPath</a> |
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<a href="apiref.html">API Reference</a> |
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<a href="toc.html">Table of Contents</a>
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</td>
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<td width="*" align="right"><div class="spirit-nav">
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<a accesskey="p" href="dom.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../manual.html"><img src="../images/up.png" alt="Up"></a><a accesskey="h" href="../manual.html"><img src="../images/home.png" alt="Home"></a><a accesskey="n" href="access.html"><img src="../images/next.png" alt="Next"></a>
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</div></td>
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</tr></table>
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<hr>
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<div class="section">
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
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<a name="manual.loading"></a><a class="link" href="loading.html" title="Loading document"> Loading document</a>
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</h2></div></div></div>
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<div class="toc"><dl class="toc">
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<dt><span class="section"><a href="loading.html#manual.loading.file"> Loading document from file</a></span></dt>
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<dt><span class="section"><a href="loading.html#manual.loading.memory"> Loading document from memory</a></span></dt>
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<dt><span class="section"><a href="loading.html#manual.loading.stream"> Loading document from C++ IOstreams</a></span></dt>
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<dt><span class="section"><a href="loading.html#manual.loading.errors"> Handling parsing errors</a></span></dt>
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<dt><span class="section"><a href="loading.html#manual.loading.options"> Parsing options</a></span></dt>
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<dt><span class="section"><a href="loading.html#manual.loading.encoding"> Encodings</a></span></dt>
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<dt><span class="section"><a href="loading.html#manual.loading.w3c"> Conformance to W3C specification</a></span></dt>
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</dl></div>
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<p>
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pugixml provides several functions for loading XML data from various places
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- files, C++ iostreams, memory buffers. All functions use an extremely fast
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non-validating parser. This parser is not fully W3C conformant - it can load
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any valid XML document, but does not perform some well-formedness checks. While
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considerable effort is made to reject invalid XML documents, some validation
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is not performed for performance reasons. Also some XML transformations (i.e.
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EOL handling or attribute value normalization) can impact parsing speed and
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thus can be disabled. However for vast majority of XML documents there is no
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performance difference between different parsing options. Parsing options also
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control whether certain XML nodes are parsed; see <a class="xref" href="loading.html#manual.loading.options" title="Parsing options"> Parsing options</a> for
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more information.
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</p>
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<p>
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XML data is always converted to internal character format (see <a class="xref" href="dom.html#manual.dom.unicode" title="Unicode interface"> Unicode interface</a>)
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before parsing. pugixml supports all popular Unicode encodings (UTF-8, UTF-16
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(big and little endian), UTF-32 (big and little endian); UCS-2 is naturally
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supported since it's a strict subset of UTF-16) and handles all encoding conversions
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automatically. Unless explicit encoding is specified, loading functions perform
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automatic encoding detection based on first few characters of XML data, so
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in almost all cases you do not have to specify document encoding. Encoding
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conversion is described in more detail in <a class="xref" href="loading.html#manual.loading.encoding" title="Encodings"> Encodings</a>.
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</p>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="manual.loading.file"></a><a class="link" href="loading.html#manual.loading.file" title="Loading document from file"> Loading document from file</a>
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</h3></div></div></div>
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<a name="xml_document::load_file"></a><a name="xml_document::load_file_wide"></a><p>
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The most common source of XML data is files; pugixml provides dedicated functions
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for loading an XML document from file:
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</p>
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<pre class="programlisting"><span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_file</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">path</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">,</span> <span class="identifier">xml_encoding</span> <span class="identifier">encoding</span> <span class="special">=</span> <span class="identifier">encoding_auto</span><span class="special">);</span>
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<span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_file</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">wchar_t</span><span class="special">*</span> <span class="identifier">path</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">,</span> <span class="identifier">xml_encoding</span> <span class="identifier">encoding</span> <span class="special">=</span> <span class="identifier">encoding_auto</span><span class="special">);</span>
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</pre>
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<p>
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These functions accept the file path as its first argument, and also two
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optional arguments, which specify parsing options (see <a class="xref" href="loading.html#manual.loading.options" title="Parsing options"> Parsing options</a>)
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and input data encoding (see <a class="xref" href="loading.html#manual.loading.encoding" title="Encodings"> Encodings</a>). The path has the target
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operating system format, so it can be a relative or absolute one, it should
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have the delimiters of the target system, it should have the exact case if
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the target file system is case-sensitive, etc.
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</p>
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<p>
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File path is passed to the system file opening function as is in case of
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the first function (which accepts <code class="computeroutput"><span class="keyword">const</span>
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<span class="keyword">char</span><span class="special">*</span> <span class="identifier">path</span></code>); the second function either uses
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a special file opening function if it is provided by the runtime library
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or converts the path to UTF-8 and uses the system file opening function.
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</p>
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<p>
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<code class="computeroutput"><span class="identifier">load_file</span></code> destroys the existing
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document tree and then tries to load the new tree from the specified file.
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The result of the operation is returned in an <a class="link" href="loading.html#xml_parse_result">xml_parse_result</a>
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object; this object contains the operation status and the related information
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(i.e. last successfully parsed position in the input file, if parsing fails).
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See <a class="xref" href="loading.html#manual.loading.errors" title="Handling parsing errors"> Handling parsing errors</a> for error handling details.
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</p>
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<p>
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This is an example of loading XML document from file (<a href="../samples/load_file.cpp" target="_top">samples/load_file.cpp</a>):
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</p>
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<p>
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</p>
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<pre class="programlisting"><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_document</span> <span class="identifier">doc</span><span class="special">;</span>
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<span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_file</span><span class="special">(</span><span class="string">"tree.xml"</span><span class="special">);</span>
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<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Load result: "</span> <span class="special"><<</span> <span class="identifier">result</span><span class="special">.</span><span class="identifier">description</span><span class="special">()</span> <span class="special"><<</span> <span class="string">", mesh name: "</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"mesh"</span><span class="special">).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"name"</span><span class="special">).</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
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</pre>
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<p>
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</p>
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</div>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="manual.loading.memory"></a><a class="link" href="loading.html#manual.loading.memory" title="Loading document from memory"> Loading document from memory</a>
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</h3></div></div></div>
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<a name="xml_document::load_buffer"></a><a name="xml_document::load_buffer_inplace"></a><a name="xml_document::load_buffer_inplace_own"></a><p>
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Sometimes XML data should be loaded from some other source than a file, i.e.
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HTTP URL; also you may want to load XML data from file using non-standard
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functions, i.e. to use your virtual file system facilities or to load XML
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from gzip-compressed files. All these scenarios require loading document
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from memory. First you should prepare a contiguous memory block with all
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XML data; then you have to invoke one of buffer loading functions. These
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functions will handle the necessary encoding conversions, if any, and then
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will parse the data into the corresponding XML tree. There are several buffer
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loading functions, which differ in the behavior and thus in performance/memory
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usage:
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</p>
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<pre class="programlisting"><span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_buffer</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*</span> <span class="identifier">contents</span><span class="special">,</span> <span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">,</span> <span class="identifier">xml_encoding</span> <span class="identifier">encoding</span> <span class="special">=</span> <span class="identifier">encoding_auto</span><span class="special">);</span>
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<span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_buffer_inplace</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span> <span class="identifier">contents</span><span class="special">,</span> <span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">,</span> <span class="identifier">xml_encoding</span> <span class="identifier">encoding</span> <span class="special">=</span> <span class="identifier">encoding_auto</span><span class="special">);</span>
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<span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_buffer_inplace_own</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span> <span class="identifier">contents</span><span class="special">,</span> <span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">,</span> <span class="identifier">xml_encoding</span> <span class="identifier">encoding</span> <span class="special">=</span> <span class="identifier">encoding_auto</span><span class="special">);</span>
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</pre>
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<p>
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All functions accept the buffer which is represented by a pointer to XML
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data, <code class="computeroutput"><span class="identifier">contents</span></code>, and data
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size in bytes. Also there are two optional arguments, which specify parsing
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options (see <a class="xref" href="loading.html#manual.loading.options" title="Parsing options"> Parsing options</a>) and input data encoding (see <a class="xref" href="loading.html#manual.loading.encoding" title="Encodings"> Encodings</a>).
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The buffer does not have to be zero-terminated.
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</p>
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<p>
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<code class="computeroutput"><span class="identifier">load_buffer</span></code> function works
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with immutable buffer - it does not ever modify the buffer. Because of this
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restriction it has to create a private buffer and copy XML data to it before
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parsing (applying encoding conversions if necessary). This copy operation
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carries a performance penalty, so inplace functions are provided - <code class="computeroutput"><span class="identifier">load_buffer_inplace</span></code> and <code class="computeroutput"><span class="identifier">load_buffer_inplace_own</span></code>
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store the document data in the buffer, modifying it in the process. In order
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for the document to stay valid, you have to make sure that the buffer's lifetime
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exceeds that of the tree if you're using inplace functions. In addition to
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that, <code class="computeroutput"><span class="identifier">load_buffer_inplace</span></code>
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does not assume ownership of the buffer, so you'll have to destroy it yourself;
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<code class="computeroutput"><span class="identifier">load_buffer_inplace_own</span></code> assumes
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ownership of the buffer and destroys it once it is not needed. This means
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that if you're using <code class="computeroutput"><span class="identifier">load_buffer_inplace_own</span></code>,
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you have to allocate memory with pugixml allocation function (you can get
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it via <a class="link" href="dom.html#get_memory_allocation_function">get_memory_allocation_function</a>).
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</p>
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<p>
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The best way from the performance/memory point of view is to load document
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using <code class="computeroutput"><span class="identifier">load_buffer_inplace_own</span></code>;
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this function has maximum control of the buffer with XML data so it is able
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to avoid redundant copies and reduce peak memory usage while parsing. This
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is the recommended function if you have to load the document from memory
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and performance is critical.
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</p>
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<a name="xml_document::load_string"></a><p>
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There is also a simple helper function for cases when you want to load the
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XML document from null-terminated character string:
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</p>
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<pre class="programlisting"><span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_string</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">contents</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">);</span>
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</pre>
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<p>
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It is equivalent to calling <code class="computeroutput"><span class="identifier">load_buffer</span></code>
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with <code class="computeroutput"><span class="identifier">size</span></code> being either <code class="computeroutput"><span class="identifier">strlen</span><span class="special">(</span><span class="identifier">contents</span><span class="special">)</span></code>
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or <code class="computeroutput"><span class="identifier">wcslen</span><span class="special">(</span><span class="identifier">contents</span><span class="special">)</span> <span class="special">*</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="keyword">wchar_t</span><span class="special">)</span></code>,
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depending on the character type. This function assumes native encoding for
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input data, so it does not do any encoding conversion. In general, this function
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is fine for loading small documents from string literals, but has more overhead
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and less functionality than the buffer loading functions.
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</p>
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<p>
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This is an example of loading XML document from memory using different functions
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(<a href="../samples/load_memory.cpp" target="_top">samples/load_memory.cpp</a>):
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</p>
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<p>
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</p>
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<pre class="programlisting"><span class="keyword">const</span> <span class="keyword">char</span> <span class="identifier">source</span><span class="special">[]</span> <span class="special">=</span> <span class="string">"<mesh name='sphere'><bounds>0 0 1 1</bounds></mesh>"</span><span class="special">;</span>
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<span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">source</span><span class="special">);</span>
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</pre>
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<p>
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</p>
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<p>
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</p>
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<pre class="programlisting"><span class="comment">// You can use load_buffer to load document from immutable memory block:
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</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_buffer</span><span class="special">(</span><span class="identifier">source</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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</pre>
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<p>
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</p>
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<p>
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</p>
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<pre class="programlisting"><span class="comment">// You can use load_buffer_inplace to load document from mutable memory block; the block's lifetime must exceed that of document
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</span><span class="keyword">char</span><span class="special">*</span> <span class="identifier">buffer</span> <span class="special">=</span> <span class="keyword">new</span> <span class="keyword">char</span><span class="special">[</span><span class="identifier">size</span><span class="special">];</span>
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<span class="identifier">memcpy</span><span class="special">(</span><span class="identifier">buffer</span><span class="special">,</span> <span class="identifier">source</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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<span class="comment">// The block can be allocated by any method; the block is modified during parsing
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</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_buffer_inplace</span><span class="special">(</span><span class="identifier">buffer</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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<span class="comment">// You have to destroy the block yourself after the document is no longer used
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</span><span class="keyword">delete</span><span class="special">[]</span> <span class="identifier">buffer</span><span class="special">;</span>
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</pre>
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<p>
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</p>
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<p>
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</p>
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<pre class="programlisting"><span class="comment">// You can use load_buffer_inplace_own to load document from mutable memory block and to pass the ownership of this block
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</span><span class="comment">// The block has to be allocated via pugixml allocation function - using i.e. operator new here is incorrect
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</span><span class="keyword">char</span><span class="special">*</span> <span class="identifier">buffer</span> <span class="special">=</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">char</span><span class="special">*>(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">get_memory_allocation_function</span><span class="special">()(</span><span class="identifier">size</span><span class="special">));</span>
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<span class="identifier">memcpy</span><span class="special">(</span><span class="identifier">buffer</span><span class="special">,</span> <span class="identifier">source</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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<span class="comment">// The block will be deleted by the document
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</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_buffer_inplace_own</span><span class="special">(</span><span class="identifier">buffer</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
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</pre>
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<p>
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</p>
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<p>
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</p>
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<pre class="programlisting"><span class="comment">// You can use load to load document from null-terminated strings, for example literals:
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</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_string</span><span class="special">(</span><span class="string">"<mesh name='sphere'><bounds>0 0 1 1</bounds></mesh>"</span><span class="special">);</span>
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</pre>
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<p>
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</p>
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</div>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.loading.stream"></a><a class="link" href="loading.html#manual.loading.stream" title="Loading document from C++ IOstreams"> Loading document from C++ IOstreams</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_document::load_stream"></a><p>
|
|
To enhance interoperability, pugixml provides functions for loading document
|
|
from any object which implements C++ <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span></code>
|
|
interface. This allows you to load documents from any standard C++ stream
|
|
(i.e. file stream) or any third-party compliant implementation (i.e. Boost
|
|
Iostreams). There are two functions, one works with narrow character streams,
|
|
another handles wide character ones:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&</span> <span class="identifier">stream</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">,</span> <span class="identifier">xml_encoding</span> <span class="identifier">encoding</span> <span class="special">=</span> <span class="identifier">encoding_auto</span><span class="special">);</span>
|
|
<span class="identifier">xml_parse_result</span> <span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">wistream</span><span class="special">&</span> <span class="identifier">stream</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">options</span> <span class="special">=</span> <span class="identifier">parse_default</span><span class="special">);</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">load</span></code> with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span></code>
|
|
argument loads the document from stream from the current read position to
|
|
the end, treating the stream contents as a byte stream of the specified encoding
|
|
(with encoding autodetection as necessary). Thus calling <code class="computeroutput"><span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load</span></code>
|
|
on an opened <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">ifstream</span></code> object is equivalent to calling
|
|
<code class="computeroutput"><span class="identifier">xml_document</span><span class="special">::</span><span class="identifier">load_file</span></code>.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">load</span></code> with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">wstream</span></code>
|
|
argument treats the stream contents as a wide character stream (encoding
|
|
is always <a class="link" href="loading.html#encoding_wchar">encoding_wchar</a>). Because
|
|
of this, using <code class="computeroutput"><span class="identifier">load</span></code> with
|
|
wide character streams requires careful (usually platform-specific) stream
|
|
setup (i.e. using the <code class="computeroutput"><span class="identifier">imbue</span></code>
|
|
function). Generally use of wide streams is discouraged, however it provides
|
|
you the ability to load documents from non-Unicode encodings, i.e. you can
|
|
load Shift-JIS encoded data if you set the correct locale.
|
|
</p>
|
|
<p>
|
|
This is a simple example of loading XML document from file using streams
|
|
(<a href="../samples/load_stream.cpp" target="_top">samples/load_stream.cpp</a>); read
|
|
the sample code for more complex examples involving wide streams and locales:
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">ifstream</span> <span class="identifier">stream</span><span class="special">(</span><span class="string">"weekly-utf-8.xml"</span><span class="special">);</span>
|
|
<span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load</span><span class="special">(</span><span class="identifier">stream</span><span class="special">);</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.loading.errors"></a><a class="link" href="loading.html#manual.loading.errors" title="Handling parsing errors"> Handling parsing errors</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_parse_result"></a><p>
|
|
All document loading functions return the parsing result via <code class="computeroutput"><span class="identifier">xml_parse_result</span></code> object. It contains parsing
|
|
status, the offset of last successfully parsed character from the beginning
|
|
of the source stream, and the encoding of the source stream:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">xml_parse_result</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">xml_parse_status</span> <span class="identifier">status</span><span class="special">;</span>
|
|
<span class="identifier">ptrdiff_t</span> <span class="identifier">offset</span><span class="special">;</span>
|
|
<span class="identifier">xml_encoding</span> <span class="identifier">encoding</span><span class="special">;</span>
|
|
|
|
<span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">description</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="special">};</span>
|
|
</pre>
|
|
<a name="xml_parse_status"></a><a name="xml_parse_result::status"></a><p>
|
|
Parsing status is represented as the <code class="computeroutput"><span class="identifier">xml_parse_status</span></code>
|
|
enumeration and can be one of the following:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
|
<li class="listitem">
|
|
<a name="status_ok"></a><code class="literal">status_ok</code> means that no error was encountered
|
|
during parsing; the source stream represents the valid XML document which
|
|
was fully parsed and converted to a tree. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_file_not_found"></a><code class="literal">status_file_not_found</code> is only
|
|
returned by <code class="computeroutput"><span class="identifier">load_file</span></code>
|
|
function and means that file could not be opened.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_io_error"></a><code class="literal">status_io_error</code> is returned by <code class="computeroutput"><span class="identifier">load_file</span></code> function and by <code class="computeroutput"><span class="identifier">load</span></code> functions with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span></code>/<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">wstream</span></code> arguments; it means that some
|
|
I/O error has occurred during reading the file/stream.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_out_of_memory"></a><code class="literal">status_out_of_memory</code> means that
|
|
there was not enough memory during some allocation; any allocation failure
|
|
during parsing results in this error.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_internal_error"></a><code class="literal">status_internal_error</code> means that
|
|
something went horribly wrong; currently this error does not occur <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_unrecognized_tag"></a><code class="literal">status_unrecognized_tag</code> means
|
|
that parsing stopped due to a tag with either an empty name or a name
|
|
which starts with incorrect character, such as <code class="literal">#</code>.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_bad_pi"></a><code class="literal">status_bad_pi</code> means that parsing stopped
|
|
due to incorrect document declaration/processing instruction
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_bad_comment"></a><code class="literal">status_bad_comment</code>, <a name="status_bad_cdata"></a><code class="literal">status_bad_cdata</code>,
|
|
<a name="status_bad_doctype"></a><code class="literal">status_bad_doctype</code> and <a name="status_bad_pcdata"></a><code class="literal">status_bad_pcdata</code>
|
|
mean that parsing stopped due to the invalid construct of the respective
|
|
type
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_bad_start_element"></a><code class="literal">status_bad_start_element</code> means
|
|
that parsing stopped because starting tag either had no closing <code class="computeroutput"><span class="special">></span></code> symbol or contained some incorrect
|
|
symbol
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_bad_attribute"></a><code class="literal">status_bad_attribute</code> means that
|
|
parsing stopped because there was an incorrect attribute, such as an
|
|
attribute without value or with value that is not quoted (note that
|
|
<code class="computeroutput"><span class="special"><</span><span class="identifier">node</span>
|
|
<span class="identifier">attr</span><span class="special">=</span><span class="number">1</span><span class="special">></span></code> is
|
|
incorrect in XML)
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_bad_end_element"></a><code class="literal">status_bad_end_element</code> means
|
|
that parsing stopped because ending tag had incorrect syntax (i.e. extra
|
|
non-whitespace symbols between tag name and <code class="computeroutput"><span class="special">></span></code>)
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_end_element_mismatch"></a><code class="literal">status_end_element_mismatch</code>
|
|
means that parsing stopped because the closing tag did not match the
|
|
opening one (i.e. <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">></</span><span class="identifier">nedo</span><span class="special">></span></code>) or because some tag was not closed
|
|
at all
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="status_no_document_element"></a><code class="literal">status_no_document_element</code>
|
|
means that no element nodes were discovered during parsing; this usually
|
|
indicates an empty or invalid document
|
|
</li>
|
|
</ul></div>
|
|
<a name="xml_parse_result::description"></a><p>
|
|
<code class="computeroutput"><span class="identifier">description</span><span class="special">()</span></code>
|
|
member function can be used to convert parsing status to a string; the returned
|
|
message is always in English, so you'll have to write your own function if
|
|
you need a localized string. However please note that the exact messages
|
|
returned by <code class="computeroutput"><span class="identifier">description</span><span class="special">()</span></code>
|
|
function may change from version to version, so any complex status handling
|
|
should be based on <code class="computeroutput"><span class="identifier">status</span></code>
|
|
value. Note that <code class="computeroutput"><span class="identifier">description</span><span class="special">()</span></code> returns a <code class="computeroutput"><span class="keyword">char</span></code>
|
|
string even in <code class="computeroutput"><span class="identifier">PUGIXML_WCHAR_MODE</span></code>;
|
|
you'll have to call <a class="link" href="dom.html#as_wide">as_wide</a> to get the <code class="computeroutput"><span class="keyword">wchar_t</span></code> string.
|
|
</p>
|
|
<p>
|
|
If parsing failed because the source data was not a valid XML, the resulting
|
|
tree is not destroyed - despite the fact that load function returns error,
|
|
you can use the part of the tree that was successfully parsed. Obviously,
|
|
the last element may have an unexpected name/value; for example, if the attribute
|
|
value does not end with the necessary quotation mark, like in <code class="literal"><node
|
|
attr="value>some data</node></code> example, the value of
|
|
attribute <code class="computeroutput"><span class="identifier">attr</span></code> will contain
|
|
the string <code class="computeroutput"><span class="identifier">value</span><span class="special">></span><span class="identifier">some</span> <span class="identifier">data</span><span class="special"></</span><span class="identifier">node</span><span class="special">></span></code>.
|
|
</p>
|
|
<a name="xml_parse_result::offset"></a><p>
|
|
In addition to the status code, parsing result has an <code class="computeroutput"><span class="identifier">offset</span></code>
|
|
member, which contains the offset of last successfully parsed character if
|
|
parsing failed because of an error in source data; otherwise <code class="computeroutput"><span class="identifier">offset</span></code> is 0. For parsing efficiency reasons,
|
|
pugixml does not track the current line during parsing; this offset is in
|
|
units of <a class="link" href="dom.html#char_t">pugi::char_t</a> (bytes for character
|
|
mode, wide characters for wide character mode). Many text editors support
|
|
'Go To Position' feature - you can use it to locate the exact error position.
|
|
Alternatively, if you're loading the document from memory, you can display
|
|
the error chunk along with the error description (see the example code below).
|
|
</p>
|
|
<div class="caution"><table border="0" summary="Caution">
|
|
<tr>
|
|
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Caution]" src="../images/caution.png"></td>
|
|
<th align="left">Caution</th>
|
|
</tr>
|
|
<tr><td align="left" valign="top"><p>
|
|
Offset is calculated in the XML buffer in native encoding; if encoding
|
|
conversion is performed during parsing, offset can not be used to reliably
|
|
track the error position.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<a name="xml_parse_result::encoding"></a><p>
|
|
Parsing result also has an <code class="computeroutput"><span class="identifier">encoding</span></code>
|
|
member, which can be used to check that the source data encoding was correctly
|
|
guessed. It is equal to the exact encoding used during parsing (i.e. with
|
|
the exact endianness); see <a class="xref" href="loading.html#manual.loading.encoding" title="Encodings"> Encodings</a> for more information.
|
|
</p>
|
|
<a name="xml_parse_result::bool"></a><p>
|
|
Parsing result object can be implicitly converted to <code class="computeroutput"><span class="keyword">bool</span></code>;
|
|
if you do not want to handle parsing errors thoroughly, you can just check
|
|
the return value of load functions as if it was a <code class="computeroutput"><span class="keyword">bool</span></code>:
|
|
<code class="computeroutput"><span class="keyword">if</span> <span class="special">(</span><span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_file</span><span class="special">(</span><span class="string">"file.xml"</span><span class="special">))</span> <span class="special">{</span> <span class="special">...</span>
|
|
<span class="special">}</span> <span class="keyword">else</span> <span class="special">{</span> <span class="special">...</span> <span class="special">}</span></code>.
|
|
</p>
|
|
<p>
|
|
This is an example of handling loading errors (<a href="../samples/load_error_handling.cpp" target="_top">samples/load_error_handling.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_document</span> <span class="identifier">doc</span><span class="special">;</span>
|
|
<span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_parse_result</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_string</span><span class="special">(</span><span class="identifier">source</span><span class="special">);</span>
|
|
|
|
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">result</span><span class="special">)</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"XML ["</span> <span class="special"><<</span> <span class="identifier">source</span> <span class="special"><<</span> <span class="string">"] parsed without errors, attr value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"node"</span><span class="special">).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"attr"</span><span class="special">).</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"]\n\n"</span><span class="special">;</span>
|
|
<span class="keyword">else</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"XML ["</span> <span class="special"><<</span> <span class="identifier">source</span> <span class="special"><<</span> <span class="string">"] parsed with errors, attr value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"node"</span><span class="special">).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"attr"</span><span class="special">).</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"]\n"</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Error description: "</span> <span class="special"><<</span> <span class="identifier">result</span><span class="special">.</span><span class="identifier">description</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"\n"</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Error offset: "</span> <span class="special"><<</span> <span class="identifier">result</span><span class="special">.</span><span class="identifier">offset</span> <span class="special"><<</span> <span class="string">" (error at [..."</span> <span class="special"><<</span> <span class="special">(</span><span class="identifier">source</span> <span class="special">+</span> <span class="identifier">result</span><span class="special">.</span><span class="identifier">offset</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"]\n\n"</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.loading.options"></a><a class="link" href="loading.html#manual.loading.options" title="Parsing options"> Parsing options</a>
|
|
</h3></div></div></div>
|
|
<p>
|
|
All document loading functions accept the optional parameter <code class="computeroutput"><span class="identifier">options</span></code>. This is a bitmask that customizes
|
|
the parsing process: you can select the node types that are parsed and various
|
|
transformations that are performed with the XML text. Disabling certain transformations
|
|
can improve parsing performance for some documents; however, the code for
|
|
all transformations is very well optimized, and thus the majority of documents
|
|
won't get any performance benefit. As a rule of thumb, only modify parsing
|
|
flags if you want to get some nodes in the document that are excluded by
|
|
default (i.e. declaration or comment nodes).
|
|
</p>
|
|
<div class="note"><table border="0" summary="Note">
|
|
<tr>
|
|
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../images/note.png"></td>
|
|
<th align="left">Note</th>
|
|
</tr>
|
|
<tr><td align="left" valign="top"><p>
|
|
You should use the usual bitwise arithmetics to manipulate the bitmask:
|
|
to enable a flag, use <code class="computeroutput"><span class="identifier">mask</span> <span class="special">|</span> <span class="identifier">flag</span></code>;
|
|
to disable a flag, use <code class="computeroutput"><span class="identifier">mask</span> <span class="special">&</span> <span class="special">~</span><span class="identifier">flag</span></code>.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<p>
|
|
These flags control the resulting tree contents:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
|
<li class="listitem">
|
|
<a name="parse_declaration"></a><code class="literal">parse_declaration</code> determines if XML
|
|
document declaration (node with type <a class="link" href="dom.html#node_declaration">node_declaration</a>)
|
|
is to be put in DOM tree. If this flag is off, it is not put in the tree,
|
|
but is still parsed and checked for correctness. This flag is <span class="bold"><strong>off</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_doctype"></a><code class="literal">parse_doctype</code> determines if XML document
|
|
type declaration (node with type <a class="link" href="dom.html#node_doctype">node_doctype</a>)
|
|
is to be put in DOM tree. If this flag is off, it is not put in the tree,
|
|
but is still parsed and checked for correctness. This flag is <span class="bold"><strong>off</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_pi"></a><code class="literal">parse_pi</code> determines if processing instructions
|
|
(nodes with type <a class="link" href="dom.html#node_pi">node_pi</a>) are to be put
|
|
in DOM tree. If this flag is off, they are not put in the tree, but are
|
|
still parsed and checked for correctness. Note that <code class="computeroutput"><span class="special"><?</span><span class="identifier">xml</span> <span class="special">...?></span></code>
|
|
(document declaration) is not considered to be a PI. This flag is <span class="bold"><strong>off</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_comments"></a><code class="literal">parse_comments</code> determines if comments
|
|
(nodes with type <a class="link" href="dom.html#node_comment">node_comment</a>) are
|
|
to be put in DOM tree. If this flag is off, they are not put in the tree,
|
|
but are still parsed and checked for correctness. This flag is <span class="bold"><strong>off</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_cdata"></a><code class="literal">parse_cdata</code> determines if CDATA sections
|
|
(nodes with type <a class="link" href="dom.html#node_cdata">node_cdata</a>) are to
|
|
be put in DOM tree. If this flag is off, they are not put in the tree,
|
|
but are still parsed and checked for correctness. This flag is <span class="bold"><strong>on</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_trim_pcdata"></a><code class="literal">parse_trim_pcdata</code> determines if leading
|
|
and trailing whitespace characters are to be removed from PCDATA nodes.
|
|
While for some applications leading/trailing whitespace is significant,
|
|
often the application only cares about the non-whitespace contents so
|
|
it's easier to trim whitespace from text during parsing. This flag is
|
|
<span class="bold"><strong>off</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_ws_pcdata"></a><code class="literal">parse_ws_pcdata</code> determines if PCDATA
|
|
nodes (nodes with type <a class="link" href="dom.html#node_pcdata">node_pcdata</a>)
|
|
that consist only of whitespace characters are to be put in DOM tree.
|
|
Often whitespace-only data is not significant for the application, and
|
|
the cost of allocating and storing such nodes (both memory and speed-wise)
|
|
can be significant. For example, after parsing XML string <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">></span> <span class="special"><</span><span class="identifier">a</span><span class="special">/></span> <span class="special"></</span><span class="identifier">node</span><span class="special">></span></code>, <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">></span></code>
|
|
element will have three children when <code class="computeroutput"><span class="identifier">parse_ws_pcdata</span></code>
|
|
is set (child with type <a class="link" href="dom.html#node_pcdata">node_pcdata</a>
|
|
and value <code class="computeroutput"><span class="string">" "</span></code>,
|
|
child with type <a class="link" href="dom.html#node_element">node_element</a> and
|
|
name <code class="computeroutput"><span class="string">"a"</span></code>, and another
|
|
child with type <a class="link" href="dom.html#node_pcdata">node_pcdata</a> and value
|
|
<code class="computeroutput"><span class="string">" "</span></code>), and only
|
|
one child when <code class="computeroutput"><span class="identifier">parse_ws_pcdata</span></code>
|
|
is not set. This flag is <span class="bold"><strong>off</strong></span> by default.
|
|
<br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_ws_pcdata_single"></a><code class="literal">parse_ws_pcdata_single</code> determines
|
|
if whitespace-only PCDATA nodes that have no sibling nodes are to be
|
|
put in DOM tree. In some cases application needs to parse the whitespace-only
|
|
contents of nodes, i.e. <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">></span>
|
|
<span class="special"></</span><span class="identifier">node</span><span class="special">></span></code>, but is not interested in whitespace
|
|
markup elsewhere. It is possible to use <a class="link" href="loading.html#parse_ws_pcdata">parse_ws_pcdata</a>
|
|
flag in this case, but it results in excessive allocations and complicates
|
|
document processing in some cases; this flag is intended to avoid that.
|
|
As an example, after parsing XML string <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">></span>
|
|
<span class="special"><</span><span class="identifier">a</span><span class="special">></span> <span class="special"></</span><span class="identifier">a</span><span class="special">></span> <span class="special"></</span><span class="identifier">node</span><span class="special">></span></code> with <code class="computeroutput"><span class="identifier">parse_ws_pcdata_single</span></code>
|
|
flag set, <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">></span></code> element will have one child <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">></span></code>, and <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">></span></code>
|
|
element will have one child with type <a class="link" href="dom.html#node_pcdata">node_pcdata</a>
|
|
and value <code class="computeroutput"><span class="string">" "</span></code>.
|
|
This flag has no effect if <a class="link" href="loading.html#parse_ws_pcdata">parse_ws_pcdata</a>
|
|
is enabled. This flag is <span class="bold"><strong>off</strong></span> by default.
|
|
<br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_fragment"></a><code class="literal">parse_fragment</code> determines if document
|
|
should be treated as a fragment of a valid XML. Parsing document as a
|
|
fragment leads to top-level PCDATA content (i.e. text that is not located
|
|
inside a node) to be added to a tree, and additionally treats documents
|
|
without element nodes as valid. This flag is <span class="bold"><strong>off</strong></span>
|
|
by default.
|
|
</li>
|
|
</ul></div>
|
|
<div class="caution"><table border="0" summary="Caution">
|
|
<tr>
|
|
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Caution]" src="../images/caution.png"></td>
|
|
<th align="left">Caution</th>
|
|
</tr>
|
|
<tr><td align="left" valign="top"><p>
|
|
Using in-place parsing (<a class="link" href="loading.html#xml_document::load_buffer_inplace">load_buffer_inplace</a>)
|
|
with <code class="computeroutput"><span class="identifier">parse_fragment</span></code> flag
|
|
may result in the loss of the last character of the buffer if it is a part
|
|
of PCDATA. Since PCDATA values are null-terminated strings, the only way
|
|
to resolve this is to provide a null-terminated buffer as an input to
|
|
<code class="computeroutput"><span class="identifier">load_buffer_inplace</span></code> - i.e.
|
|
<code class="computeroutput"><span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_buffer_inplace</span><span class="special">(</span><span class="string">"test\0"</span><span class="special">,</span>
|
|
<span class="number">5</span><span class="special">,</span> <span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_default</span> <span class="special">|</span>
|
|
<span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_fragment</span><span class="special">)</span></code>.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<p>
|
|
These flags control the transformation of tree element contents:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
|
<li class="listitem">
|
|
<a name="parse_escapes"></a><code class="literal">parse_escapes</code> determines if character
|
|
and entity references are to be expanded during the parsing process.
|
|
Character references have the form <code class="literal">&#...;</code> or
|
|
<code class="literal">&#x...;</code> (<code class="literal">...</code> is Unicode numeric
|
|
representation of character in either decimal (<code class="literal">&#...;</code>)
|
|
or hexadecimal (<code class="literal">&#x...;</code>) form), entity references
|
|
are <code class="literal">&lt;</code>, <code class="literal">&gt;</code>, <code class="literal">&amp;</code>,
|
|
<code class="literal">&apos;</code> and <code class="literal">&quot;</code> (note
|
|
that as pugixml does not handle DTD, the only allowed entities are predefined
|
|
ones). If character/entity reference can not be expanded, it is left
|
|
as is, so you can do additional processing later. Reference expansion
|
|
is performed on attribute values and PCDATA content. This flag is <span class="bold"><strong>on</strong></span> by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_eol"></a><code class="literal">parse_eol</code> determines if EOL handling (that
|
|
is, replacing sequences <code class="computeroutput"><span class="number">0x0d</span> <span class="number">0x0a</span></code> by a single <code class="computeroutput"><span class="number">0x0a</span></code>
|
|
character, and replacing all standalone <code class="computeroutput"><span class="number">0x0d</span></code>
|
|
characters by <code class="computeroutput"><span class="number">0x0a</span></code>) is to
|
|
be performed on input data (that is, comments contents, PCDATA/CDATA
|
|
contents and attribute values). This flag is <span class="bold"><strong>on</strong></span>
|
|
by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_wconv_attribute"></a><code class="literal">parse_wconv_attribute</code> determines
|
|
if attribute value normalization should be performed for all attributes.
|
|
This means, that whitespace characters (new line, tab and space) are
|
|
replaced with space (<code class="computeroutput"><span class="char">' '</span></code>).
|
|
New line characters are always treated as if <a class="link" href="loading.html#parse_eol">parse_eol</a>
|
|
is set, i.e. <code class="computeroutput"><span class="special">\</span><span class="identifier">r</span><span class="special">\</span><span class="identifier">n</span></code>
|
|
is converted to a single space. This flag is <span class="bold"><strong>on</strong></span>
|
|
by default. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_wnorm_attribute"></a><code class="literal">parse_wnorm_attribute</code> determines
|
|
if extended attribute value normalization should be performed for all
|
|
attributes. This means, that after attribute values are normalized as
|
|
if <a class="link" href="loading.html#parse_wconv_attribute">parse_wconv_attribute</a>
|
|
was set, leading and trailing space characters are removed, and all sequences
|
|
of space characters are replaced by a single space character. <a class="link" href="loading.html#parse_wconv_attribute">parse_wconv_attribute</a>
|
|
has no effect if this flag is on. This flag is <span class="bold"><strong>off</strong></span>
|
|
by default.
|
|
</li>
|
|
</ul></div>
|
|
<div class="note"><table border="0" summary="Note">
|
|
<tr>
|
|
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../images/note.png"></td>
|
|
<th align="left">Note</th>
|
|
</tr>
|
|
<tr><td align="left" valign="top"><p>
|
|
<code class="computeroutput"><span class="identifier">parse_wconv_attribute</span></code> option
|
|
performs transformations that are required by W3C specification for attributes
|
|
that are declared as <code class="literal">CDATA</code>; <a class="link" href="loading.html#parse_wnorm_attribute">parse_wnorm_attribute</a>
|
|
performs transformations required for <code class="literal">NMTOKENS</code> attributes.
|
|
In the absence of document type declaration all attributes should behave
|
|
as if they are declared as <code class="literal">CDATA</code>, thus <a class="link" href="loading.html#parse_wconv_attribute">parse_wconv_attribute</a>
|
|
is the default option.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<p>
|
|
Additionally there are three predefined option masks:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
|
<li class="listitem">
|
|
<a name="parse_minimal"></a><code class="literal">parse_minimal</code> has all options turned
|
|
off. This option mask means that pugixml does not add declaration nodes,
|
|
document type declaration nodes, PI nodes, CDATA sections and comments
|
|
to the resulting tree and does not perform any conversion for input data,
|
|
so theoretically it is the fastest mode. However, as mentioned above,
|
|
in practice <a class="link" href="loading.html#parse_default">parse_default</a> is usually
|
|
equally fast. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_default"></a><code class="literal">parse_default</code> is the default set of flags,
|
|
i.e. it has all options set to their default values. It includes parsing
|
|
CDATA sections (comments/PIs are not parsed), performing character and
|
|
entity reference expansion, replacing whitespace characters with spaces
|
|
in attribute values and performing EOL handling. Note, that PCDATA sections
|
|
consisting only of whitespace characters are not parsed (by default)
|
|
for performance reasons. <br><br>
|
|
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="parse_full"></a><code class="literal">parse_full</code> is the set of flags which adds
|
|
nodes of all types to the resulting tree and performs default conversions
|
|
for input data. It includes parsing CDATA sections, comments, PI nodes,
|
|
document declaration node and document type declaration node, performing
|
|
character and entity reference expansion, replacing whitespace characters
|
|
with spaces in attribute values and performing EOL handling. Note, that
|
|
PCDATA sections consisting only of whitespace characters are not parsed
|
|
in this mode.
|
|
</li>
|
|
</ul></div>
|
|
<p>
|
|
This is an example of using different parsing options (<a href="../samples/load_options.cpp" target="_top">samples/load_options.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">source</span> <span class="special">=</span> <span class="string">"<!--comment--><node>&lt;</node>"</span><span class="special">;</span>
|
|
|
|
<span class="comment">// Parsing with default options; note that comment node is not added to the tree, and entity reference &lt; is expanded
|
|
</span><span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_string</span><span class="special">(</span><span class="identifier">source</span><span class="special">);</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"First node value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">first_child</span><span class="special">().</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"], node child value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">(</span><span class="string">"node"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"]\n"</span><span class="special">;</span>
|
|
|
|
<span class="comment">// Parsing with additional parse_comments option; comment node is now added to the tree
|
|
</span><span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_string</span><span class="special">(</span><span class="identifier">source</span><span class="special">,</span> <span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_default</span> <span class="special">|</span> <span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_comments</span><span class="special">);</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"First node value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">first_child</span><span class="special">().</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"], node child value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">(</span><span class="string">"node"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"]\n"</span><span class="special">;</span>
|
|
|
|
<span class="comment">// Parsing with additional parse_comments option and without the (default) parse_escapes option; &lt; is not expanded
|
|
</span><span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_string</span><span class="special">(</span><span class="identifier">source</span><span class="special">,</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_default</span> <span class="special">|</span> <span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_comments</span><span class="special">)</span> <span class="special">&</span> <span class="special">~</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_escapes</span><span class="special">);</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"First node value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">first_child</span><span class="special">().</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"], node child value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">(</span><span class="string">"node"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"]\n"</span><span class="special">;</span>
|
|
|
|
<span class="comment">// Parsing with minimal option mask; comment node is not added to the tree, and &lt; is not expanded
|
|
</span><span class="identifier">doc</span><span class="special">.</span><span class="identifier">load_string</span><span class="special">(</span><span class="identifier">source</span><span class="special">,</span> <span class="identifier">pugi</span><span class="special">::</span><span class="identifier">parse_minimal</span><span class="special">);</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"First node value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">first_child</span><span class="special">().</span><span class="identifier">value</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"], node child value: ["</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">(</span><span class="string">"node"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"]\n"</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.loading.encoding"></a><a class="link" href="loading.html#manual.loading.encoding" title="Encodings"> Encodings</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_encoding"></a><p>
|
|
pugixml supports all popular Unicode encodings (UTF-8, UTF-16 (big and little
|
|
endian), UTF-32 (big and little endian); UCS-2 is naturally supported since
|
|
it's a strict subset of UTF-16) and handles all encoding conversions. Most
|
|
loading functions accept the optional parameter <code class="computeroutput"><span class="identifier">encoding</span></code>.
|
|
This is a value of enumeration type <code class="computeroutput"><span class="identifier">xml_encoding</span></code>,
|
|
that can have the following values:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
|
<li class="listitem">
|
|
<a name="encoding_auto"></a><code class="literal">encoding_auto</code> means that pugixml will
|
|
try to guess the encoding based on source XML data. The algorithm is
|
|
a modified version of the one presented in Appendix F.1 of XML recommendation;
|
|
it tries to match the first few bytes of input data with the following
|
|
patterns in strict order: <br><br>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; ">
|
|
<li class="listitem">
|
|
If first four bytes match UTF-32 BOM (Byte Order Mark), encoding
|
|
is assumed to be UTF-32 with the endianness equal to that of BOM;
|
|
</li>
|
|
<li class="listitem">
|
|
If first two bytes match UTF-16 BOM, encoding is assumed to be
|
|
UTF-16 with the endianness equal to that of BOM;
|
|
</li>
|
|
<li class="listitem">
|
|
If first three bytes match UTF-8 BOM, encoding is assumed to be
|
|
UTF-8;
|
|
</li>
|
|
<li class="listitem">
|
|
If first four bytes match UTF-32 representation of <code class="literal"><</code>,
|
|
encoding is assumed to be UTF-32 with the corresponding endianness;
|
|
</li>
|
|
<li class="listitem">
|
|
If first four bytes match UTF-16 representation of <code class="literal"><?</code>,
|
|
encoding is assumed to be UTF-16 with the corresponding endianness;
|
|
</li>
|
|
<li class="listitem">
|
|
If first two bytes match UTF-16 representation of <code class="literal"><</code>,
|
|
encoding is assumed to be UTF-16 with the corresponding endianness
|
|
(this guess may yield incorrect result, but it's better than UTF-8);
|
|
</li>
|
|
<li class="listitem">
|
|
Otherwise encoding is assumed to be UTF-8. <br><br>
|
|
|
|
</li>
|
|
</ul></div>
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf8"></a><code class="literal">encoding_utf8</code> corresponds to UTF-8 encoding
|
|
as defined in the Unicode standard; UTF-8 sequences with length equal
|
|
to 5 or 6 are not standard and are rejected.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf16_le"></a><code class="literal">encoding_utf16_le</code> corresponds to
|
|
little-endian UTF-16 encoding as defined in the Unicode standard; surrogate
|
|
pairs are supported.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf16_be"></a><code class="literal">encoding_utf16_be</code> corresponds to
|
|
big-endian UTF-16 encoding as defined in the Unicode standard; surrogate
|
|
pairs are supported.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf16"></a><code class="literal">encoding_utf16</code> corresponds to UTF-16
|
|
encoding as defined in the Unicode standard; the endianness is assumed
|
|
to be that of the target platform.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf32_le"></a><code class="literal">encoding_utf32_le</code> corresponds to
|
|
little-endian UTF-32 encoding as defined in the Unicode standard.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf32_be"></a><code class="literal">encoding_utf32_be</code> corresponds to
|
|
big-endian UTF-32 encoding as defined in the Unicode standard.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_utf32"></a><code class="literal">encoding_utf32</code> corresponds to UTF-32
|
|
encoding as defined in the Unicode standard; the endianness is assumed
|
|
to be that of the target platform.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_wchar"></a><code class="literal">encoding_wchar</code> corresponds to the encoding
|
|
of <code class="computeroutput"><span class="keyword">wchar_t</span></code> type; it has
|
|
the same meaning as either <code class="computeroutput"><span class="identifier">encoding_utf16</span></code>
|
|
or <code class="computeroutput"><span class="identifier">encoding_utf32</span></code>, depending
|
|
on <code class="computeroutput"><span class="keyword">wchar_t</span></code> size.
|
|
</li>
|
|
<li class="listitem">
|
|
<a name="encoding_latin1"></a><code class="literal">encoding_latin1</code> corresponds to ISO-8859-1
|
|
encoding (also known as Latin-1).
|
|
</li>
|
|
</ul></div>
|
|
<p>
|
|
The algorithm used for <code class="computeroutput"><span class="identifier">encoding_auto</span></code>
|
|
correctly detects any supported Unicode encoding for all well-formed XML
|
|
documents (since they start with document declaration) and for all other
|
|
XML documents that start with <code class="literal"><</code>; if your XML document
|
|
does not start with <code class="literal"><</code> and has encoding that is different
|
|
from UTF-8, use the specific encoding.
|
|
</p>
|
|
<div class="note"><table border="0" summary="Note">
|
|
<tr>
|
|
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../images/note.png"></td>
|
|
<th align="left">Note</th>
|
|
</tr>
|
|
<tr><td align="left" valign="top"><p>
|
|
The current behavior for Unicode conversion is to skip all invalid UTF
|
|
sequences during conversion. This behavior should not be relied upon; moreover,
|
|
in case no encoding conversion is performed, the invalid sequences are
|
|
not removed, so you'll get them as is in node/attribute contents.
|
|
</p></td></tr>
|
|
</table></div>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.loading.w3c"></a><a class="link" href="loading.html#manual.loading.w3c" title="Conformance to W3C specification"> Conformance to W3C specification</a>
|
|
</h3></div></div></div>
|
|
<p>
|
|
pugixml is not fully W3C conformant - it can load any valid XML document,
|
|
but does not perform some well-formedness checks. While considerable effort
|
|
is made to reject invalid XML documents, some validation is not performed
|
|
because of performance reasons.
|
|
</p>
|
|
<p>
|
|
There is only one non-conformant behavior when dealing with valid XML documents:
|
|
pugixml does not use information supplied in document type declaration for
|
|
parsing. This means that entities declared in DOCTYPE are not expanded, and
|
|
all attribute/PCDATA values are always processed in a uniform way that depends
|
|
only on parsing options.
|
|
</p>
|
|
<p>
|
|
As for rejecting invalid XML documents, there are a number of incompatibilities
|
|
with W3C specification, including:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
|
<li class="listitem">
|
|
Multiple attributes of the same node can have equal names.
|
|
</li>
|
|
<li class="listitem">
|
|
All non-ASCII characters are treated in the same way as symbols of English
|
|
alphabet, so some invalid tag names are not rejected.
|
|
</li>
|
|
<li class="listitem">
|
|
Attribute values which contain <code class="literal"><</code> are not rejected.
|
|
</li>
|
|
<li class="listitem">
|
|
Invalid entity/character references are not rejected and are instead
|
|
left as is.
|
|
</li>
|
|
<li class="listitem">
|
|
Comment values can contain <code class="literal">--</code>.
|
|
</li>
|
|
<li class="listitem">
|
|
XML data is not required to begin with document declaration; additionally,
|
|
document declaration can appear after comments and other nodes.
|
|
</li>
|
|
<li class="listitem">
|
|
Invalid document type declarations are silently ignored in some cases.
|
|
</li>
|
|
</ul></div>
|
|
</div>
|
|
</div>
|
|
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
|
<td align="left"></td>
|
|
<td align="right"><div class="copyright-footer">Copyright © 2014 Arseny Kapoulkine<p>
|
|
Distributed under the MIT License
|
|
</p>
|
|
</div></td>
|
|
</tr></table>
|
|
<hr>
|
|
<table width="100%"><tr>
|
|
<td>
|
|
<a href="http://pugixml.org/">pugixml 1.5</a> manual |
|
|
<a href="../manual.html">Overview</a> |
|
|
<a href="install.html">Installation</a> |
|
|
Document:
|
|
<a href="dom.html">Object model</a> · <b>Loading</b> · <a href="access.html">Accessing</a> · <a href="modify.html">Modifying</a> · <a href="saving.html">Saving</a> |
|
|
<a href="xpath.html">XPath</a> |
|
|
<a href="apiref.html">API Reference</a> |
|
|
<a href="toc.html">Table of Contents</a>
|
|
</td>
|
|
<td width="*" align="right"><div class="spirit-nav">
|
|
<a accesskey="p" href="dom.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../manual.html"><img src="../images/up.png" alt="Up"></a><a accesskey="h" href="../manual.html"><img src="../images/home.png" alt="Home"></a><a accesskey="n" href="access.html"><img src="../images/next.png" alt="Next"></a>
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|
</div></td>
|
|
</tr></table>
|
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</body>
|
|
</html>
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