mirror of
https://github.com/moparisthebest/mailiverse
synced 2024-11-06 09:25:01 -05:00
893 lines
97 KiB
HTML
893 lines
97 KiB
HTML
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
|
<title>Accessing document data</title>
|
|
<link rel="stylesheet" href="../pugixml.css" type="text/css">
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
|
|
<link rel="home" href="../manual.html" title="pugixml 1.2">
|
|
<link rel="up" href="../manual.html" title="pugixml 1.2">
|
|
<link rel="prev" href="loading.html" title="Loading document">
|
|
<link rel="next" href="modify.html" title="Modifying document data">
|
|
</head>
|
|
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
|
<table width="100%"><tr>
|
|
<td>
|
|
<a href="http://pugixml.org/">pugixml 1.2</a> manual |
|
|
<a href="../manual.html">Overview</a> |
|
|
<a href="install.html">Installation</a> |
|
|
Document:
|
|
<a href="dom.html">Object model</a> · <a href="loading.html">Loading</a> · <b>Accessing</b> · <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="loading.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="modify.html"><img src="../images/next.png" alt="Next"></a>
|
|
</div></td>
|
|
</tr></table>
|
|
<hr>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
|
<a name="manual.access"></a><a class="link" href="access.html" title="Accessing document data"> Accessing document data</a>
|
|
</h2></div></div></div>
|
|
<div class="toc"><dl>
|
|
<dt><span class="section"><a href="access.html#manual.access.basic"> Basic traversal functions</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.nodedata"> Getting node data</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.attrdata"> Getting attribute data</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.contents"> Contents-based traversal functions</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.rangefor"> Range-based for-loop support</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.iterators"> Traversing node/attribute lists
|
|
via iterators</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.walker"> Recursive traversal with xml_tree_walker</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.predicate"> Searching for nodes/attributes
|
|
with predicates</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.text"> Working with text contents</a></span></dt>
|
|
<dt><span class="section"><a href="access.html#manual.access.misc"> Miscellaneous functions</a></span></dt>
|
|
</dl></div>
|
|
<p>
|
|
pugixml features an extensive interface for getting various types of data from
|
|
the document and for traversing the document. This section provides documentation
|
|
for all such functions that do not modify the tree except for XPath-related
|
|
functions; see <a class="xref" href="xpath.html" title="XPath"> XPath</a> for XPath reference. As discussed in <a class="xref" href="dom.html#manual.dom.cpp" title="C++ interface"> C++ interface</a>,
|
|
there are two types of handles to tree data - <a class="link" href="dom.html#xml_node">xml_node</a>
|
|
and <a class="link" href="dom.html#xml_attribute">xml_attribute</a>. The handles have special
|
|
null (empty) values which propagate through various functions and thus are
|
|
useful for writing more concise code; see <a class="link" href="dom.html#node_null">this description</a>
|
|
for details. The documentation in this section will explicitly state the results
|
|
of all function in case of null inputs.
|
|
</p>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.basic"></a><a class="link" href="access.html#manual.access.basic" title="Basic traversal functions"> Basic traversal functions</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node::parent"></a><a name="xml_node::first_child"></a><a name="xml_node::last_child"></a><a name="xml_node::next_sibling"></a><a name="xml_node::previous_sibling"></a><a name="xml_node::first_attribute"></a><a name="xml_node::last_attribute"></a><a name="xml_attribute::next_attribute"></a><a name="xml_attribute::previous_attribute"></a><p>
|
|
The internal representation of the document is a tree, where each node has
|
|
a list of child nodes (the order of children corresponds to their order in
|
|
the XML representation), and additionally element nodes have a list of attributes,
|
|
which is also ordered. Several functions are provided in order to let you
|
|
get from one node in the tree to the other. These functions roughly correspond
|
|
to the internal representation, and thus are usually building blocks for
|
|
other methods of traversing (i.e. XPath traversals are based on these functions).
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">parent</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">first_child</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">last_child</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">next_sibling</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">previous_sibling</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
|
|
<span class="identifier">xml_attribute</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">first_attribute</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_attribute</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">last_attribute</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_attribute</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">next_attribute</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_attribute</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">previous_attribute</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">parent</span></code> function returns the
|
|
node's parent; all non-null nodes except the document have non-null parent.
|
|
<code class="computeroutput"><span class="identifier">first_child</span></code> and <code class="computeroutput"><span class="identifier">last_child</span></code> return the first and last child
|
|
of the node, respectively; note that only document nodes and element nodes
|
|
can have non-empty child node list. If node has no children, both functions
|
|
return null nodes. <code class="computeroutput"><span class="identifier">next_sibling</span></code>
|
|
and <code class="computeroutput"><span class="identifier">previous_sibling</span></code> return
|
|
the node that's immediately to the right/left of this node in the children
|
|
list, respectively - for example, in <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">/><</span><span class="identifier">b</span><span class="special">/><</span><span class="identifier">c</span><span class="special">/></span></code>,
|
|
calling <code class="computeroutput"><span class="identifier">next_sibling</span></code> for
|
|
a handle that points to <code class="computeroutput"><span class="special"><</span><span class="identifier">b</span><span class="special">/></span></code>
|
|
results in a handle pointing to <code class="computeroutput"><span class="special"><</span><span class="identifier">c</span><span class="special">/></span></code>,
|
|
and calling <code class="computeroutput"><span class="identifier">previous_sibling</span></code>
|
|
results in handle pointing to <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">/></span></code>.
|
|
If node does not have next/previous sibling (this happens if it is the last/first
|
|
node in the list, respectively), the functions return null nodes. <code class="computeroutput"><span class="identifier">first_attribute</span></code>, <code class="computeroutput"><span class="identifier">last_attribute</span></code>,
|
|
<code class="computeroutput"><span class="identifier">next_attribute</span></code> and <code class="computeroutput"><span class="identifier">previous_attribute</span></code> functions behave similarly
|
|
to the corresponding child node functions and allow to iterate through attribute
|
|
list in the same way.
|
|
</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>
|
|
Because of memory consumption reasons, attributes do not have a link to
|
|
their parent nodes. Thus there is no <code class="computeroutput"><span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">parent</span><span class="special">()</span></code> function.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<p>
|
|
Calling any of the functions above on the null handle results in a null handle
|
|
- i.e. <code class="computeroutput"><span class="identifier">node</span><span class="special">.</span><span class="identifier">first_child</span><span class="special">().</span><span class="identifier">next_sibling</span><span class="special">()</span></code>
|
|
returns the second child of <code class="computeroutput"><span class="identifier">node</span></code>,
|
|
and null handle if <code class="computeroutput"><span class="identifier">node</span></code> is
|
|
null, has no children at all or if it has only one child node.
|
|
</p>
|
|
<p>
|
|
With these functions, you can iterate through all child nodes and display
|
|
all attributes like this (<a href="../samples/traverse_base.cpp" target="_top">samples/traverse_base.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">first_child</span><span class="special">();</span> <span class="identifier">tool</span><span class="special">;</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">next_sibling</span><span class="special">())</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">"Tool:"</span><span class="special">;</span>
|
|
|
|
<span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_attribute</span> <span class="identifier">attr</span> <span class="special">=</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">first_attribute</span><span class="special">();</span> <span class="identifier">attr</span><span class="special">;</span> <span class="identifier">attr</span> <span class="special">=</span> <span class="identifier">attr</span><span class="special">.</span><span class="identifier">next_attribute</span><span class="special">())</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">" "</span> <span class="special"><<</span> <span class="identifier">attr</span><span class="special">.</span><span class="identifier">name</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"="</span> <span class="special"><<</span> <span class="identifier">attr</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">cout</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</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.access.nodedata"></a><a class="link" href="access.html#manual.access.nodedata" title="Getting node data"> Getting node data</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node::name"></a><a name="xml_node::value"></a><p>
|
|
Apart from structural information (parent, child nodes, attributes), nodes
|
|
can have name and value, both of which are strings. Depending on node type,
|
|
name or value may be absent. <a class="link" href="dom.html#node_document">node_document</a>
|
|
nodes do not have a name or value, <a class="link" href="dom.html#node_element">node_element</a>
|
|
and <a class="link" href="dom.html#node_declaration">node_declaration</a> nodes always
|
|
have a name but never have a value, <a class="link" href="dom.html#node_pcdata">node_pcdata</a>,
|
|
<a class="link" href="dom.html#node_cdata">node_cdata</a>, <a class="link" href="dom.html#node_comment">node_comment</a>
|
|
and <a class="link" href="dom.html#node_doctype">node_doctype</a> nodes never have a name
|
|
but always have a value (it may be empty though), <a class="link" href="dom.html#node_pi">node_pi</a>
|
|
nodes always have a name and a value (again, value may be empty). In order
|
|
to get node's name or value, you can use the following functions:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">name</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
In case node does not have a name or value or if the node handle is null,
|
|
both functions return empty strings - they never return null pointers.
|
|
</p>
|
|
<a name="xml_node::child_value"></a><p>
|
|
It is common to store data as text contents of some node - i.e. <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">><</span><span class="identifier">description</span><span class="special">></span><span class="identifier">This</span> <span class="identifier">is</span> <span class="identifier">a</span> <span class="identifier">node</span><span class="special"></</span><span class="identifier">description</span><span class="special">></</span><span class="identifier">node</span><span class="special">></span></code>.
|
|
In this case, <code class="computeroutput"><span class="special"><</span><span class="identifier">description</span><span class="special">></span></code> node does not have a value, but instead
|
|
has a child of type <a class="link" href="dom.html#node_pcdata">node_pcdata</a> with value
|
|
<code class="computeroutput"><span class="string">"This is a node"</span></code>. pugixml
|
|
provides several helper functions to parse such data:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">child_value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">child_value</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_text</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">text</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">child_value</span><span class="special">()</span></code>
|
|
returns the value of the first child with type <a class="link" href="dom.html#node_pcdata">node_pcdata</a>
|
|
or <a class="link" href="dom.html#node_cdata">node_cdata</a>; <code class="computeroutput"><span class="identifier">child_value</span><span class="special">(</span><span class="identifier">name</span><span class="special">)</span></code>
|
|
is a simple wrapper for <code class="computeroutput"><span class="identifier">child</span><span class="special">(</span><span class="identifier">name</span><span class="special">).</span><span class="identifier">child_value</span><span class="special">()</span></code>.
|
|
For the above example, calling <code class="computeroutput"><span class="identifier">node</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">(</span><span class="string">"description"</span><span class="special">)</span></code> and <code class="computeroutput"><span class="identifier">description</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">()</span></code> will both produce string <code class="computeroutput"><span class="string">"This is a node"</span></code>. If there is no
|
|
child with relevant type, or if the handle is null, <code class="computeroutput"><span class="identifier">child_value</span></code>
|
|
functions return empty string.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">text</span><span class="special">()</span></code>
|
|
returns a special object that can be used for working with PCDATA contents
|
|
in more complex cases than just retrieving the value; it is described in
|
|
<a class="xref" href="access.html#manual.access.text" title="Working with text contents"> Working with text contents</a> sections.
|
|
</p>
|
|
<p>
|
|
There is an example of using some of these functions <a class="link" href="access.html#code_traverse_base_data">at
|
|
the end of the next section</a>.
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.attrdata"></a><a class="link" href="access.html#manual.access.attrdata" title="Getting attribute data"> Getting attribute data</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_attribute::name"></a><a name="xml_attribute::value"></a><p>
|
|
All attributes have name and value, both of which are strings (value may
|
|
be empty). There are two corresponding accessors, like for <code class="computeroutput"><span class="identifier">xml_node</span></code>:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">name</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
In case the attribute handle is null, both functions return empty strings
|
|
- they never return null pointers.
|
|
</p>
|
|
<a name="xml_attribute::as_string"></a><p>
|
|
If you need a non-empty string if the attribute handle is null (for example,
|
|
you need to get the option value from XML attribute, but if it is not specified,
|
|
you need it to default to <code class="computeroutput"><span class="string">"sorted"</span></code>
|
|
instead of <code class="computeroutput"><span class="string">""</span></code>), you
|
|
can use <code class="computeroutput"><span class="identifier">as_string</span></code> accessor:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">as_string</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">def</span> <span class="special">=</span> <span class="string">""</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
It returns <code class="computeroutput"><span class="identifier">def</span></code> argument if
|
|
the attribute handle is null. If you do not specify the argument, the function
|
|
is equivalent to <code class="computeroutput"><span class="identifier">value</span><span class="special">()</span></code>.
|
|
</p>
|
|
<a name="xml_attribute::as_int"></a><a name="xml_attribute::as_uint"></a><a name="xml_attribute::as_double"></a><a name="xml_attribute::as_float"></a><a name="xml_attribute::as_bool"></a><p>
|
|
In many cases attribute values have types that are not strings - i.e. an
|
|
attribute may always contain values that should be treated as integers, despite
|
|
the fact that they are represented as strings in XML. pugixml provides several
|
|
accessors that convert attribute value to some other type:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">as_int</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">as_uint</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">double</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">as_double</span><span class="special">(</span><span class="keyword">double</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">float</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">as_float</span><span class="special">(</span><span class="keyword">float</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">bool</span> <span class="identifier">xml_attribute</span><span class="special">::</span><span class="identifier">as_bool</span><span class="special">(</span><span class="keyword">bool</span> <span class="identifier">def</span> <span class="special">=</span> <span class="keyword">false</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">as_int</span></code>, <code class="computeroutput"><span class="identifier">as_uint</span></code>,
|
|
<code class="computeroutput"><span class="identifier">as_double</span></code> and <code class="computeroutput"><span class="identifier">as_float</span></code> convert attribute values to numbers.
|
|
If attribute handle is null or attribute value is empty, <code class="computeroutput"><span class="identifier">def</span></code>
|
|
argument is returned (which is 0 by default). Otherwise, all leading whitespace
|
|
characters are truncated, and the remaining string is parsed as a decimal
|
|
number (<code class="computeroutput"><span class="identifier">as_int</span></code> or <code class="computeroutput"><span class="identifier">as_uint</span></code>) or as a floating point number
|
|
in either decimal or scientific form (<code class="computeroutput"><span class="identifier">as_double</span></code>
|
|
or <code class="computeroutput"><span class="identifier">as_float</span></code>). Any extra characters
|
|
are silently discarded, i.e. <code class="computeroutput"><span class="identifier">as_int</span></code>
|
|
will return <code class="computeroutput"><span class="number">1</span></code> for string <code class="computeroutput"><span class="string">"1abc"</span></code>.
|
|
</p>
|
|
<p>
|
|
In case the input string contains a number that is out of the target numeric
|
|
range, the result is undefined.
|
|
</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>
|
|
Number conversion functions depend on current C locale as set with <code class="computeroutput"><span class="identifier">setlocale</span></code>, so may return unexpected results
|
|
if the locale is different from <code class="computeroutput"><span class="string">"C"</span></code>.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">as_bool</span></code> converts attribute
|
|
value to boolean as follows: if attribute handle is null, <code class="computeroutput"><span class="identifier">def</span></code>
|
|
argument is returned (which is <code class="computeroutput"><span class="keyword">false</span></code>
|
|
by default). If attribute value is empty, <code class="computeroutput"><span class="keyword">false</span></code>
|
|
is returned. Otherwise, <code class="computeroutput"><span class="keyword">true</span></code>
|
|
is returned if the first character is one of <code class="computeroutput"><span class="char">'1'</span><span class="special">,</span> <span class="char">'t'</span><span class="special">,</span>
|
|
<span class="char">'T'</span><span class="special">,</span> <span class="char">'y'</span><span class="special">,</span> <span class="char">'Y'</span></code>.
|
|
This means that strings like <code class="computeroutput"><span class="string">"true"</span></code>
|
|
and <code class="computeroutput"><span class="string">"yes"</span></code> are recognized
|
|
as <code class="computeroutput"><span class="keyword">true</span></code>, while strings like
|
|
<code class="computeroutput"><span class="string">"false"</span></code> and <code class="computeroutput"><span class="string">"no"</span></code> are recognized as <code class="computeroutput"><span class="keyword">false</span></code>. For more complex matching you'll have
|
|
to write your own function.
|
|
</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>
|
|
There are no portable 64-bit types in C++, so there is no corresponding
|
|
conversion function. If your platform has a 64-bit integer, you can easily
|
|
write a conversion function yourself.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<a name="code_traverse_base_data"></a><p>
|
|
This is an example of using these functions, along with node data retrieval
|
|
ones (<a href="../samples/traverse_base.cpp" target="_top">samples/traverse_base.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">);</span> <span class="identifier">tool</span><span class="special">;</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">next_sibling</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">))</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">"Tool "</span> <span class="special"><<</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Filename"</span><span class="special">).</span><span class="identifier">value</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">": AllowRemote "</span> <span class="special"><<</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"AllowRemote"</span><span class="special">).</span><span class="identifier">as_bool</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">", Timeout "</span> <span class="special"><<</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Timeout"</span><span class="special">).</span><span class="identifier">as_int</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">", Description '"</span> <span class="special"><<</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">child_value</span><span class="special">(</span><span class="string">"Description"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"'\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.access.contents"></a><a class="link" href="access.html#manual.access.contents" title="Contents-based traversal functions"> Contents-based traversal functions</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node::child"></a><a name="xml_node::attribute"></a><a name="xml_node::next_sibling_name"></a><a name="xml_node::previous_sibling_name"></a><p>
|
|
Since a lot of document traversal consists of finding the node/attribute
|
|
with the correct name, there are special functions for that purpose:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">child</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_attribute</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">attribute</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">next_sibling</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">previous_sibling</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">child</span></code> and <code class="computeroutput"><span class="identifier">attribute</span></code>
|
|
return the first child/attribute with the specified name; <code class="computeroutput"><span class="identifier">next_sibling</span></code>
|
|
and <code class="computeroutput"><span class="identifier">previous_sibling</span></code> return
|
|
the first sibling in the corresponding direction with the specified name.
|
|
All string comparisons are case-sensitive. In case the node handle is null
|
|
or there is no node/attribute with the specified name, null handle is returned.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">child</span></code> and <code class="computeroutput"><span class="identifier">next_sibling</span></code>
|
|
functions can be used together to loop through all child nodes with the desired
|
|
name like this:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">);</span> <span class="identifier">tool</span><span class="special">;</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">next_sibling</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">))</span>
|
|
</pre>
|
|
<a name="xml_node::find_child_by_attribute"></a><p>
|
|
Occasionally the needed node is specified not by the unique name but instead
|
|
by the value of some attribute; for example, it is common to have node collections
|
|
with each node having a unique id: <code class="computeroutput"><span class="special"><</span><span class="identifier">group</span><span class="special">><</span><span class="identifier">item</span> <span class="identifier">id</span><span class="special">=</span><span class="string">"1"</span><span class="special">/></span> <span class="special"><</span><span class="identifier">item</span> <span class="identifier">id</span><span class="special">=</span><span class="string">"2"</span><span class="special">/></</span><span class="identifier">group</span><span class="special">></span></code>. There are two functions for finding
|
|
child nodes based on the attribute values:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">find_child_by_attribute</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">attr_name</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">attr_value</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">find_child_by_attribute</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">attr_name</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">attr_value</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
The three-argument function returns the first child node with the specified
|
|
name which has an attribute with the specified name/value; the two-argument
|
|
function skips the name test for the node, which can be useful for searching
|
|
in heterogeneous collections. If the node handle is null or if no node is
|
|
found, null handle is returned. All string comparisons are case-sensitive.
|
|
</p>
|
|
<p>
|
|
In all of the above functions, all arguments have to be valid strings; passing
|
|
null pointers results in undefined behavior.
|
|
</p>
|
|
<p>
|
|
This is an example of using these functions (<a href="../samples/traverse_base.cpp" target="_top">samples/traverse_base.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Tool for *.dae generation: "</span> <span class="special"><<</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">find_child_by_attribute</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">,</span> <span class="string">"OutputFileMasks"</span><span class="special">,</span> <span class="string">"*.dae"</span><span class="special">).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Filename"</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="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">);</span> <span class="identifier">tool</span><span class="special">;</span> <span class="identifier">tool</span> <span class="special">=</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">next_sibling</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">))</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">"Tool "</span> <span class="special"><<</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Filename"</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="special">}</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.rangefor"></a><a class="link" href="access.html#manual.access.rangefor" title="Range-based for-loop support"> Range-based for-loop support</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node::children"></a><a name="xml_node::attributes"></a><p>
|
|
If your C++ compiler supports range-based for-loop (this is a C++11 feature,
|
|
at the time of writing it's supported by Microsoft Visual Studio 11 Beta,
|
|
GCC 4.6 and Clang 3.0), you can use it to enumerate nodes/attributes. Additional
|
|
helpers are provided to support this; note that they are also compatible
|
|
with <a href="http://www.boost.org/libs/foreach/" target="_top">Boost Foreach</a>,
|
|
and possibly other pre-C++11 foreach facilities.
|
|
</p>
|
|
<pre class="programlisting"><span class="emphasis"><em>implementation-defined type</em></span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">children</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="emphasis"><em>implementation-defined type</em></span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">children</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">name</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="emphasis"><em>implementation-defined type</em></span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">attributes</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">children</span></code> function allows
|
|
you to enumerate all child nodes; <code class="computeroutput"><span class="identifier">children</span></code>
|
|
function with <code class="computeroutput"><span class="identifier">name</span></code> argument
|
|
allows you to enumerate all child nodes with a specific name; <code class="computeroutput"><span class="identifier">attributes</span></code> function allows you to enumerate
|
|
all attributes of the node. Note that you can also use node object itself
|
|
in a range-based for construct, which is equivalent to using <code class="computeroutput"><span class="identifier">children</span><span class="special">()</span></code>.
|
|
</p>
|
|
<p>
|
|
This is an example of using these functions (<a href="../samples/traverse_rangefor.cpp" target="_top">samples/traverse_rangefor.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">tool</span><span class="special">:</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">children</span><span class="special">(</span><span class="string">"Tool"</span><span class="special">))</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">"Tool:"</span><span class="special">;</span>
|
|
|
|
<span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_attribute</span> <span class="identifier">attr</span><span class="special">:</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">attributes</span><span class="special">())</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">" "</span> <span class="special"><<</span> <span class="identifier">attr</span><span class="special">.</span><span class="identifier">name</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"="</span> <span class="special"><<</span> <span class="identifier">attr</span><span class="special">.</span><span class="identifier">value</span><span class="special">();</span>
|
|
<span class="special">}</span>
|
|
|
|
<span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">child</span><span class="special">:</span> <span class="identifier">tool</span><span class="special">.</span><span class="identifier">children</span><span class="special">())</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">", child "</span> <span class="special"><<</span> <span class="identifier">child</span><span class="special">.</span><span class="identifier">name</span><span class="special">();</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="identifier">std</span><span class="special">::</span><span class="identifier">endl</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.access.iterators"></a><a class="link" href="access.html#manual.access.iterators" title="Traversing node/attribute lists via iterators"> Traversing node/attribute lists
|
|
via iterators</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node_iterator"></a><a name="xml_attribute_iterator"></a><a name="xml_node::begin"></a><a name="xml_node::end"></a><a name="xml_node::attributes_begin"></a><a name="xml_node::attributes_end"></a><p>
|
|
Child node lists and attribute lists are simply double-linked lists; while
|
|
you can use <code class="computeroutput"><span class="identifier">previous_sibling</span></code>/<code class="computeroutput"><span class="identifier">next_sibling</span></code> and other such functions for
|
|
iteration, pugixml additionally provides node and attribute iterators, so
|
|
that you can treat nodes as containers of other nodes or attributes:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">xml_node_iterator</span><span class="special">;</span>
|
|
<span class="keyword">class</span> <span class="identifier">xml_attribute_iterator</span><span class="special">;</span>
|
|
|
|
<span class="keyword">typedef</span> <span class="identifier">xml_node_iterator</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">iterator</span><span class="special">;</span>
|
|
<span class="identifier">iterator</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">begin</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">iterator</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">end</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
|
|
<span class="keyword">typedef</span> <span class="identifier">xml_attribute_iterator</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">attribute_iterator</span><span class="special">;</span>
|
|
<span class="identifier">attribute_iterator</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">attributes_begin</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">attribute_iterator</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">attributes_end</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">begin</span></code> and <code class="computeroutput"><span class="identifier">attributes_begin</span></code>
|
|
return iterators that point to the first node/attribute, respectively; <code class="computeroutput"><span class="identifier">end</span></code> and <code class="computeroutput"><span class="identifier">attributes_end</span></code>
|
|
return past-the-end iterator for node/attribute list, respectively - this
|
|
iterator can't be dereferenced, but decrementing it results in an iterator
|
|
pointing to the last element in the list (except for empty lists, where decrementing
|
|
past-the-end iterator results in undefined behavior). Past-the-end iterator
|
|
is commonly used as a termination value for iteration loops (see sample below).
|
|
If you want to get an iterator that points to an existing handle, you can
|
|
construct the iterator with the handle as a single constructor argument,
|
|
like so: <code class="computeroutput"><span class="identifier">xml_node_iterator</span><span class="special">(</span><span class="identifier">node</span><span class="special">)</span></code>.
|
|
For <code class="computeroutput"><span class="identifier">xml_attribute_iterator</span></code>,
|
|
you'll have to provide both an attribute and its parent node.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">begin</span></code> and <code class="computeroutput"><span class="identifier">end</span></code>
|
|
return equal iterators if called on null node; such iterators can't be dereferenced.
|
|
<code class="computeroutput"><span class="identifier">attributes_begin</span></code> and <code class="computeroutput"><span class="identifier">attributes_end</span></code> behave the same way. For
|
|
correct iterator usage this means that child node/attribute collections of
|
|
null nodes appear to be empty.
|
|
</p>
|
|
<p>
|
|
Both types of iterators have bidirectional iterator semantics (i.e. they
|
|
can be incremented and decremented, but efficient random access is not supported)
|
|
and support all usual iterator operations - comparison, dereference, etc.
|
|
The iterators are invalidated if the node/attribute objects they're pointing
|
|
to are removed from the tree; adding nodes/attributes does not invalidate
|
|
any iterators.
|
|
</p>
|
|
<p>
|
|
Here is an example of using iterators for document traversal (<a href="../samples/traverse_iter.cpp" target="_top">samples/traverse_iter.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node_iterator</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">begin</span><span class="special">();</span> <span class="identifier">it</span> <span class="special">!=</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">end</span><span class="special">();</span> <span class="special">++</span><span class="identifier">it</span><span class="special">)</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">"Tool:"</span><span class="special">;</span>
|
|
|
|
<span class="keyword">for</span> <span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_attribute_iterator</span> <span class="identifier">ait</span> <span class="special">=</span> <span class="identifier">it</span><span class="special">-></span><span class="identifier">attributes_begin</span><span class="special">();</span> <span class="identifier">ait</span> <span class="special">!=</span> <span class="identifier">it</span><span class="special">-></span><span class="identifier">attributes_end</span><span class="special">();</span> <span class="special">++</span><span class="identifier">ait</span><span class="special">)</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">" "</span> <span class="special"><<</span> <span class="identifier">ait</span><span class="special">-></span><span class="identifier">name</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"="</span> <span class="special"><<</span> <span class="identifier">ait</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">cout</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
</pre>
|
|
<p>
|
|
</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>
|
|
Node and attribute iterators are somewhere in the middle between const
|
|
and non-const iterators. While dereference operation yields a non-constant
|
|
reference to the object, so that you can use it for tree modification operations,
|
|
modifying this reference by assignment - i.e. passing iterators to a function
|
|
like <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">sort</span></code> - will not give expected results,
|
|
as assignment modifies local handle that's stored in the iterator.
|
|
</p></td></tr>
|
|
</table></div>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.walker"></a><a class="link" href="access.html#manual.access.walker" title="Recursive traversal with xml_tree_walker"> Recursive traversal with xml_tree_walker</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_tree_walker"></a><p>
|
|
The methods described above allow traversal of immediate children of some
|
|
node; if you want to do a deep tree traversal, you'll have to do it via a
|
|
recursive function or some equivalent method. However, pugixml provides a
|
|
helper for depth-first traversal of a subtree. In order to use it, you have
|
|
to implement <code class="computeroutput"><span class="identifier">xml_tree_walker</span></code>
|
|
interface and to call <code class="computeroutput"><span class="identifier">traverse</span></code>
|
|
function:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">xml_tree_walker</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">public</span><span class="special">:</span>
|
|
<span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">begin</span><span class="special">(</span><span class="identifier">xml_node</span><span class="special">&</span> <span class="identifier">node</span><span class="special">);</span>
|
|
<span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">for_each</span><span class="special">(</span><span class="identifier">xml_node</span><span class="special">&</span> <span class="identifier">node</span><span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
|
|
<span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">end</span><span class="special">(</span><span class="identifier">xml_node</span><span class="special">&</span> <span class="identifier">node</span><span class="special">);</span>
|
|
|
|
<span class="keyword">int</span> <span class="identifier">depth</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="special">};</span>
|
|
|
|
<span class="keyword">bool</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">traverse</span><span class="special">(</span><span class="identifier">xml_tree_walker</span><span class="special">&</span> <span class="identifier">walker</span><span class="special">);</span>
|
|
</pre>
|
|
<a name="xml_tree_walker::begin"></a><a name="xml_tree_walker::for_each"></a><a name="xml_tree_walker::end"></a><a name="xml_node::traverse"></a><p>
|
|
The traversal is launched by calling <code class="computeroutput"><span class="identifier">traverse</span></code>
|
|
function on traversal root and proceeds as follows:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
|
|
<li class="listitem">
|
|
First, <code class="computeroutput"><span class="identifier">begin</span></code> function
|
|
is called with traversal root as its argument.
|
|
</li>
|
|
<li class="listitem">
|
|
Then, <code class="computeroutput"><span class="identifier">for_each</span></code> function
|
|
is called for all nodes in the traversal subtree in depth first order,
|
|
excluding the traversal root. Node is passed as an argument.
|
|
</li>
|
|
<li class="listitem">
|
|
Finally, <code class="computeroutput"><span class="identifier">end</span></code> function
|
|
is called with traversal root as its argument.
|
|
</li>
|
|
</ul></div>
|
|
<p>
|
|
If <code class="computeroutput"><span class="identifier">begin</span></code>, <code class="computeroutput"><span class="identifier">end</span></code>
|
|
or any of the <code class="computeroutput"><span class="identifier">for_each</span></code> calls
|
|
return <code class="computeroutput"><span class="keyword">false</span></code>, the traversal
|
|
is terminated and <code class="computeroutput"><span class="keyword">false</span></code> is returned
|
|
as the traversal result; otherwise, the traversal results in <code class="computeroutput"><span class="keyword">true</span></code>. Note that you don't have to override
|
|
<code class="computeroutput"><span class="identifier">begin</span></code> or <code class="computeroutput"><span class="identifier">end</span></code>
|
|
functions; their default implementations return <code class="computeroutput"><span class="keyword">true</span></code>.
|
|
</p>
|
|
<a name="xml_tree_walker::depth"></a><p>
|
|
You can get the node's depth relative to the traversal root at any point
|
|
by calling <code class="computeroutput"><span class="identifier">depth</span></code> function.
|
|
It returns <code class="computeroutput"><span class="special">-</span><span class="number">1</span></code>
|
|
if called from <code class="computeroutput"><span class="identifier">begin</span></code>/<code class="computeroutput"><span class="identifier">end</span></code>, and returns 0-based depth if called
|
|
from <code class="computeroutput"><span class="identifier">for_each</span></code> - depth is
|
|
0 for all children of the traversal root, 1 for all grandchildren and so
|
|
on.
|
|
</p>
|
|
<p>
|
|
This is an example of traversing tree hierarchy with xml_tree_walker (<a href="../samples/traverse_walker.cpp" target="_top">samples/traverse_walker.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">simple_walker</span><span class="special">:</span> <span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_tree_walker</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">for_each</span><span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span><span class="special">&</span> <span class="identifier">node</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">for</span> <span class="special">(</span><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">depth</span><span class="special">();</span> <span class="special">++</span><span class="identifier">i</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">" "</span><span class="special">;</span> <span class="comment">// indentation
|
|
</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">node_types</span><span class="special">[</span><span class="identifier">node</span><span class="special">.</span><span class="identifier">type</span><span class="special">()]</span> <span class="special"><<</span> <span class="string">": name='"</span> <span class="special"><<</span> <span class="identifier">node</span><span class="special">.</span><span class="identifier">name</span><span class="special">()</span> <span class="special"><<</span> <span class="string">"', value='"</span> <span class="special"><<</span> <span class="identifier">node</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="keyword">return</span> <span class="keyword">true</span><span class="special">;</span> <span class="comment">// continue traversal
|
|
</span> <span class="special">}</span>
|
|
<span class="special">};</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">simple_walker</span> <span class="identifier">walker</span><span class="special">;</span>
|
|
<span class="identifier">doc</span><span class="special">.</span><span class="identifier">traverse</span><span class="special">(</span><span class="identifier">walker</span><span class="special">);</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.predicate"></a><a class="link" href="access.html#manual.access.predicate" title="Searching for nodes/attributes with predicates"> Searching for nodes/attributes
|
|
with predicates</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node::find_attribute"></a><a name="xml_node::find_child"></a><a name="xml_node::find_node"></a><p>
|
|
While there are existing functions for getting a node/attribute with known
|
|
contents, they are often not sufficient for simple queries. As an alternative
|
|
for manual iteration through nodes/attributes until the needed one is found,
|
|
you can make a predicate and call one of <code class="computeroutput"><span class="identifier">find_</span></code>
|
|
functions:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Predicate</span><span class="special">></span> <span class="identifier">xml_attribute</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">find_attribute</span><span class="special">(</span><span class="identifier">Predicate</span> <span class="identifier">pred</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Predicate</span><span class="special">></span> <span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">find_child</span><span class="special">(</span><span class="identifier">Predicate</span> <span class="identifier">pred</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Predicate</span><span class="special">></span> <span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">find_node</span><span class="special">(</span><span class="identifier">Predicate</span> <span class="identifier">pred</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
The predicate should be either a plain function or a function object which
|
|
accepts one argument of type <code class="computeroutput"><span class="identifier">xml_attribute</span></code>
|
|
(for <code class="computeroutput"><span class="identifier">find_attribute</span></code>) or
|
|
<code class="computeroutput"><span class="identifier">xml_node</span></code> (for <code class="computeroutput"><span class="identifier">find_child</span></code> and <code class="computeroutput"><span class="identifier">find_node</span></code>),
|
|
and returns <code class="computeroutput"><span class="keyword">bool</span></code>. The predicate
|
|
is never called with null handle as an argument.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">find_attribute</span></code> function iterates
|
|
through all attributes of the specified node, and returns the first attribute
|
|
for which the predicate returned <code class="computeroutput"><span class="keyword">true</span></code>.
|
|
If the predicate returned <code class="computeroutput"><span class="keyword">false</span></code>
|
|
for all attributes or if there were no attributes (including the case where
|
|
the node is null), null attribute is returned.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">find_child</span></code> function iterates
|
|
through all child nodes of the specified node, and returns the first node
|
|
for which the predicate returned <code class="computeroutput"><span class="keyword">true</span></code>.
|
|
If the predicate returned <code class="computeroutput"><span class="keyword">false</span></code>
|
|
for all nodes or if there were no child nodes (including the case where the
|
|
node is null), null node is returned.
|
|
</p>
|
|
<p>
|
|
<code class="computeroutput"><span class="identifier">find_node</span></code> function performs
|
|
a depth-first traversal through the subtree of the specified node (excluding
|
|
the node itself), and returns the first node for which the predicate returned
|
|
<code class="computeroutput"><span class="keyword">true</span></code>. If the predicate returned
|
|
<code class="computeroutput"><span class="keyword">false</span></code> for all nodes or if subtree
|
|
was empty, null node is returned.
|
|
</p>
|
|
<p>
|
|
This is an example of using predicate-based functions (<a href="../samples/traverse_predicate.cpp" target="_top">samples/traverse_predicate.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">small_timeout</span><span class="special">(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">node</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">return</span> <span class="identifier">node</span><span class="special">.</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Timeout"</span><span class="special">).</span><span class="identifier">as_int</span><span class="special">()</span> <span class="special"><</span> <span class="number">20</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
|
|
<span class="keyword">struct</span> <span class="identifier">allow_remote_predicate</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_attribute</span> <span class="identifier">attr</span><span class="special">)</span> <span class="keyword">const</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">return</span> <span class="identifier">strcmp</span><span class="special">(</span><span class="identifier">attr</span><span class="special">.</span><span class="identifier">name</span><span class="special">(),</span> <span class="string">"AllowRemote"</span><span class="special">)</span> <span class="special">==</span> <span class="number">0</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
|
|
<span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">pugi</span><span class="special">::</span><span class="identifier">xml_node</span> <span class="identifier">node</span><span class="special">)</span> <span class="keyword">const</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">return</span> <span class="identifier">node</span><span class="special">.</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"AllowRemote"</span><span class="special">).</span><span class="identifier">as_bool</span><span class="special">();</span>
|
|
<span class="special">}</span>
|
|
<span class="special">};</span>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="comment">// Find child via predicate (looks for direct children only)
|
|
</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">find_child</span><span class="special">(</span><span class="identifier">allow_remote_predicate</span><span class="special">()).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Filename"</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>
|
|
|
|
<span class="comment">// Find node via predicate (looks for all descendants in depth-first order)
|
|
</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">doc</span><span class="special">.</span><span class="identifier">find_node</span><span class="special">(</span><span class="identifier">allow_remote_predicate</span><span class="special">()).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Filename"</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>
|
|
|
|
<span class="comment">// Find attribute via predicate
|
|
</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">last_child</span><span class="special">().</span><span class="identifier">find_attribute</span><span class="special">(</span><span class="identifier">allow_remote_predicate</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>
|
|
|
|
<span class="comment">// We can use simple functions instead of function objects
|
|
</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">tools</span><span class="special">.</span><span class="identifier">find_child</span><span class="special">(</span><span class="identifier">small_timeout</span><span class="special">).</span><span class="identifier">attribute</span><span class="special">(</span><span class="string">"Filename"</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>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.text"></a><a class="link" href="access.html#manual.access.text" title="Working with text contents"> Working with text contents</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_text"></a><p>
|
|
It is common to store data as text contents of some node - i.e. <code class="computeroutput"><span class="special"><</span><span class="identifier">node</span><span class="special">><</span><span class="identifier">description</span><span class="special">></span><span class="identifier">This</span> <span class="identifier">is</span> <span class="identifier">a</span> <span class="identifier">node</span><span class="special"></</span><span class="identifier">description</span><span class="special">></</span><span class="identifier">node</span><span class="special">></span></code>.
|
|
In this case, <code class="computeroutput"><span class="special"><</span><span class="identifier">description</span><span class="special">></span></code> node does not have a value, but instead
|
|
has a child of type <a class="link" href="dom.html#node_pcdata">node_pcdata</a> with value
|
|
<code class="computeroutput"><span class="string">"This is a node"</span></code>. pugixml
|
|
provides a special class, <code class="computeroutput"><span class="identifier">xml_text</span></code>,
|
|
to work with such data. Working with text objects to modify data is described
|
|
in <a class="link" href="modify.html#manual.modify.text" title="Working with text contents">the documentation for modifying document
|
|
data</a>; this section describes the access interface of <code class="computeroutput"><span class="identifier">xml_text</span></code>.
|
|
</p>
|
|
<a name="xml_node::text"></a><p>
|
|
You can get the text object from a node by using <code class="computeroutput"><span class="identifier">text</span><span class="special">()</span></code> method:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_text</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">text</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
If the node has a type <code class="computeroutput"><span class="identifier">node_pcdata</span></code>
|
|
or <code class="computeroutput"><span class="identifier">node_cdata</span></code>, then the node
|
|
itself is used to return data; otherwise, a first child node of type <code class="computeroutput"><span class="identifier">node_pcdata</span></code> or <code class="computeroutput"><span class="identifier">node_cdata</span></code>
|
|
is used.
|
|
</p>
|
|
<a name="xml_text::empty"></a><a name="xml_text::unspecified_bool_type"></a><p>
|
|
You can check if the text object is bound to a valid PCDATA/CDATA node by
|
|
using it as a boolean value, i.e. <code class="computeroutput"><span class="keyword">if</span>
|
|
<span class="special">(</span><span class="identifier">text</span><span class="special">)</span> <span class="special">{</span> <span class="special">...</span>
|
|
<span class="special">}</span></code> or <code class="computeroutput"><span class="keyword">if</span>
|
|
<span class="special">(!</span><span class="identifier">text</span><span class="special">)</span> <span class="special">{</span> <span class="special">...</span>
|
|
<span class="special">}</span></code>. Alternatively you can check it
|
|
by using the <code class="computeroutput"><span class="identifier">empty</span><span class="special">()</span></code>
|
|
method:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">empty</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<a name="xml_text::get"></a><p>
|
|
Given a text object, you can get the contents (i.e. the value of PCDATA/CDATA
|
|
node) by using the following function:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">get</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
In case text object is empty, the function returns an empty string - it never
|
|
returns a null pointer.
|
|
</p>
|
|
<a name="xml_text::as_string"></a><a name="xml_text::as_int"></a><a name="xml_text::as_uint"></a><a name="xml_text::as_double"></a><a name="xml_text::as_float"></a><a name="xml_text::as_bool"></a><p>
|
|
If you need a non-empty string if the text object is empty, or if the text
|
|
contents is actually a number or a boolean that is stored as a string, you
|
|
can use the following accessors:
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">as_string</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">def</span> <span class="special">=</span> <span class="string">""</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">int</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">as_int</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">as_uint</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">double</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">as_double</span><span class="special">(</span><span class="keyword">double</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">float</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">as_float</span><span class="special">(</span><span class="keyword">float</span> <span class="identifier">def</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="keyword">bool</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">as_bool</span><span class="special">(</span><span class="keyword">bool</span> <span class="identifier">def</span> <span class="special">=</span> <span class="keyword">false</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
All of the above functions have the same semantics as similar <code class="computeroutput"><span class="identifier">xml_attribute</span></code> members: they return the
|
|
default argument if the text object is empty, they convert the text contents
|
|
to a target type using the same rules and restrictions. You can <a class="link" href="access.html#xml_attribute::as_int">refer
|
|
to documentation for the attribute functions</a> for details.
|
|
</p>
|
|
<a name="xml_text::data"></a><p>
|
|
<code class="computeroutput"><span class="identifier">xml_text</span></code> is essentially a
|
|
helper class that operates on <code class="computeroutput"><span class="identifier">xml_node</span></code>
|
|
values. It is bound to a node of type <a class="link" href="dom.html#node_pcdata">node_pcdata</a>
|
|
or <a class="link" href="dom.html#node_cdata">node_cdata</a>. You can use the following
|
|
function to retrieve this node:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_node</span> <span class="identifier">xml_text</span><span class="special">::</span><span class="identifier">data</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
Essentially, assuming <code class="computeroutput"><span class="identifier">text</span></code>
|
|
is an <code class="computeroutput"><span class="identifier">xml_text</span></code> object, calling
|
|
<code class="computeroutput"><span class="identifier">text</span><span class="special">.</span><span class="identifier">get</span><span class="special">()</span></code> is
|
|
equivalent to calling <code class="computeroutput"><span class="identifier">text</span><span class="special">.</span><span class="identifier">data</span><span class="special">().</span><span class="identifier">value</span><span class="special">()</span></code>.
|
|
</p>
|
|
<p>
|
|
This is an example of using <code class="computeroutput"><span class="identifier">xml_text</span></code>
|
|
object (<a href="../samples/text.cpp" target="_top">samples/text.cpp</a>):
|
|
</p>
|
|
<p>
|
|
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Project name: "</span> <span class="special"><<</span> <span class="identifier">project</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"name"</span><span class="special">).</span><span class="identifier">text</span><span class="special">().</span><span class="identifier">get</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>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Project version: "</span> <span class="special"><<</span> <span class="identifier">project</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"version"</span><span class="special">).</span><span class="identifier">text</span><span class="special">().</span><span class="identifier">as_double</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>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Project visibility: "</span> <span class="special"><<</span> <span class="special">(</span><span class="identifier">project</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"public"</span><span class="special">).</span><span class="identifier">text</span><span class="special">().</span><span class="identifier">as_bool</span><span class="special">(/*</span> <span class="identifier">def</span><span class="special">=</span> <span class="special">*/</span> <span class="keyword">true</span><span class="special">)</span> <span class="special">?</span> <span class="string">"public"</span> <span class="special">:</span> <span class="string">"private"</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>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Project description: "</span> <span class="special"><<</span> <span class="identifier">project</span><span class="special">.</span><span class="identifier">child</span><span class="special">(</span><span class="string">"description"</span><span class="special">).</span><span class="identifier">text</span><span class="special">().</span><span class="identifier">get</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>
|
|
</pre>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="manual.access.misc"></a><a class="link" href="access.html#manual.access.misc" title="Miscellaneous functions"> Miscellaneous functions</a>
|
|
</h3></div></div></div>
|
|
<a name="xml_node::root"></a><p>
|
|
If you need to get the document root of some node, you can use the following
|
|
function:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">root</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
This function returns the node with type <a class="link" href="dom.html#node_document">node_document</a>,
|
|
which is the root node of the document the node belongs to (unless the node
|
|
is null, in which case null node is returned).
|
|
</p>
|
|
<a name="xml_node::path"></a><a name="xml_node::first_element_by_path"></a><p>
|
|
While pugixml supports complex XPath expressions, sometimes a simple path
|
|
handling facility is needed. There are two functions, for getting node path
|
|
and for converting path to a node:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">string_t</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">path</span><span class="special">(</span><span class="identifier">char_t</span> <span class="identifier">delimiter</span> <span class="special">=</span> <span class="char">'/'</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
<span class="identifier">xml_node</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">first_element_by_path</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">char_t</span><span class="special">*</span> <span class="identifier">path</span><span class="special">,</span> <span class="identifier">char_t</span> <span class="identifier">delimiter</span> <span class="special">=</span> <span class="char">'/'</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
Node paths consist of node names, separated with a delimiter (which is <code class="computeroutput"><span class="special">/</span></code> by default); also paths can contain self
|
|
(<code class="computeroutput"><span class="special">.</span></code>) and parent (<code class="computeroutput"><span class="special">..</span></code>) pseudo-names, so that this is a valid
|
|
path: <code class="computeroutput"><span class="string">"../../foo/./bar"</span></code>.
|
|
<code class="computeroutput"><span class="identifier">path</span></code> returns the path to
|
|
the node from the document root, <code class="computeroutput"><span class="identifier">first_element_by_path</span></code>
|
|
looks for a node represented by a given path; a path can be an absolute one
|
|
(absolute paths start with the delimiter), in which case the rest of the
|
|
path is treated as document root relative, and relative to the given node.
|
|
For example, in the following document: <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">><</span><span class="identifier">b</span><span class="special">><</span><span class="identifier">c</span><span class="special">/></</span><span class="identifier">b</span><span class="special">></</span><span class="identifier">a</span><span class="special">></span></code>,
|
|
node <code class="computeroutput"><span class="special"><</span><span class="identifier">c</span><span class="special">/></span></code> has path <code class="computeroutput"><span class="string">"a/b/c"</span></code>;
|
|
calling <code class="computeroutput"><span class="identifier">first_element_by_path</span></code>
|
|
for document with path <code class="computeroutput"><span class="string">"a/b"</span></code>
|
|
results in node <code class="computeroutput"><span class="special"><</span><span class="identifier">b</span><span class="special">/></span></code>; calling <code class="computeroutput"><span class="identifier">first_element_by_path</span></code>
|
|
for node <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">/></span></code> with path <code class="computeroutput"><span class="string">"../a/./b/../."</span></code>
|
|
results in node <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">/></span></code>; calling <code class="computeroutput"><span class="identifier">first_element_by_path</span></code>
|
|
with path <code class="computeroutput"><span class="string">"/a"</span></code> results
|
|
in node <code class="computeroutput"><span class="special"><</span><span class="identifier">a</span><span class="special">/></span></code> for any node.
|
|
</p>
|
|
<p>
|
|
In case path component is ambiguous (if there are two nodes with given name),
|
|
the first one is selected; paths are not guaranteed to uniquely identify
|
|
nodes in a document. If any component of a path is not found, the result
|
|
of <code class="computeroutput"><span class="identifier">first_element_by_path</span></code>
|
|
is null node; also <code class="computeroutput"><span class="identifier">first_element_by_path</span></code>
|
|
returns null node for null nodes, in which case the path does not matter.
|
|
<code class="computeroutput"><span class="identifier">path</span></code> returns an empty string
|
|
for null 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>
|
|
<code class="computeroutput"><span class="identifier">path</span></code> function returns the
|
|
result as STL string, and thus is not available if <a class="link" href="install.html#PUGIXML_NO_STL">PUGIXML_NO_STL</a>
|
|
is defined.
|
|
</p></td></tr>
|
|
</table></div>
|
|
<a name="xml_node::offset_debug"></a><p>
|
|
pugixml does not record row/column information for nodes upon parsing for
|
|
efficiency reasons. However, if the node has not changed in a significant
|
|
way since parsing (the name/value are not changed, and the node itself is
|
|
the original one, i.e. it was not deleted from the tree and re-added later),
|
|
it is possible to get the offset from the beginning of XML buffer:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">ptrdiff_t</span> <span class="identifier">xml_node</span><span class="special">::</span><span class="identifier">offset_debug</span><span class="special">()</span> <span class="keyword">const</span><span class="special">;</span>
|
|
</pre>
|
|
<p>
|
|
If the offset is not available (this happens if the node is null, was not
|
|
originally parsed from a stream, or has changed in a significant way), the
|
|
function returns -1. Otherwise it returns the offset to node's data from
|
|
the beginning of XML buffer in <a class="link" href="dom.html#char_t">pugi::char_t</a>
|
|
units. For more information on parsing offsets, see <a class="link" href="loading.html#xml_parse_result::offset">parsing
|
|
error handling documentation</a>.
|
|
</p>
|
|
</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 © 2012 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 1.2</a> manual |
|
|
<a href="../manual.html">Overview</a> |
|
|
<a href="install.html">Installation</a> |
|
|
Document:
|
|
<a href="dom.html">Object model</a> · <a href="loading.html">Loading</a> · <b>Accessing</b> · <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="loading.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="modify.html"><img src="../images/next.png" alt="Next"></a>
|
|
</div></td>
|
|
</tr></table>
|
|
</body>
|
|
</html>
|