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<head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>pattern: pattern expression handling</title> <meta name="generator" content="Libxml2 devhelp stylesheet"/> <link rel="start" href="index.html" title="libxml2 Reference Manual"/> <link rel="up" href="general.html" title="API"/> <link rel="stylesheet" href="style.css" type="text/css"/> <link rel="chapter" href="general.html" title="API"/> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table class="navigation" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"> <tr valign="middle"> <td> <a accesskey="p" href="libxml2-parserInternals.html"> <img src="left.png" width="24" height="24" border="0" alt="Prev"/> </a> </td> <td> <a accesskey="u" href="general.html"> <img src="up.png" width="24" height="24" border="0" alt="Up"/> </a> </td> <td> <a accesskey="h" href="index.html"> <img src="home.png" width="24" height="24" border="0" alt="Home"/> </a> </td> <td> <a accesskey="n" href="libxml2-relaxng.html"> <img src="right.png" width="24" height="24" border="0" alt="Next"/> </a> </td> <th width="100%" align="center">libxml2 Reference Manual</th> </tr> </table> <h2> <span class="refentrytitle">pattern</span> </h2> <p>pattern - pattern expression handling</p> <p>allows to compile and test pattern expressions for nodes either in a tree or based on a parser state. </p> <p>Author(s): Daniel Veillard </p> <div class="refsynopsisdiv"> <h2>Synopsis</h2> <pre class="synopsis">typedef <a href="libxml2-pattern.html#xmlStreamCtxt">xmlStreamCtxt</a> * <a href="#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a>;
typedef enum <a href=“#xmlPatternFlags”>xmlPatternFlags</a>; typedef struct _xmlStreamCtxt <a href=“#xmlStreamCtxt”>xmlStreamCtxt</a>; typedef struct _xmlPattern <a href=“#xmlPattern”>xmlPattern</a>; typedef <a href=“libxml2-pattern.html#xmlPattern”>xmlPattern</a> * <a href=“#xmlPatternPtr”>xmlPatternPtr</a>; int <a href=“#xmlPatternMinDepth”>xmlPatternMinDepth</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); <a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> <a href=“#xmlPatternGetStreamCtxt”>xmlPatternGetStreamCtxt</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); int <a href=“#xmlPatternFromRoot”>xmlPatternFromRoot</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); void <a href=“#xmlFreePatternList”>xmlFreePatternList</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); int <a href=“#xmlPatternStreamable”>xmlPatternStreamable</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); int <a href=“#xmlStreamPushAttr”>xmlStreamPushAttr</a> (<a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> stream, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * name, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * ns); int <a href=“#xmlPatternMatch”>xmlPatternMatch</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp, <br/> <a href=“libxml2-tree.html#xmlNodePtr”>xmlNodePtr</a> node); int <a href=“#xmlStreamWantsAnyNode”>xmlStreamWantsAnyNode</a> (<a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> streamCtxt); int <a href=“#xmlStreamPop”>xmlStreamPop</a> (<a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> stream); void <a href=“#xmlFreePattern”>xmlFreePattern</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); int <a href=“#xmlStreamPush”>xmlStreamPush</a> (<a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> stream, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * name, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * ns); int <a href=“#xmlPatternMaxDepth”>xmlPatternMaxDepth</a> (<a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> comp); <a href=“libxml2-pattern.html#xmlPatternPtr”>xmlPatternPtr</a> <a href=“#xmlPatterncompile”>xmlPatterncompile</a> (const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * pattern, <br/> <a href=“libxml2-dict.html#xmlDict”>xmlDict</a> * dict, <br/> int flags, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> ** namespaces); int <a href=“#xmlStreamPushNode”>xmlStreamPushNode</a> (<a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> stream, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * name, <br/> const <a href=“libxml2-xmlstring.html#xmlChar”>xmlChar</a> * ns, <br/> int nodeType); void <a href=“#xmlFreeStreamCtxt”>xmlFreeStreamCtxt</a> (<a href=“libxml2-pattern.html#xmlStreamCtxtPtr”>xmlStreamCtxtPtr</a> stream); </pre>
</div> <div class="refsect1" lang="en"> <h2>Description</h2> </div> <div class="refsect1" lang="en"> <h2>Details</h2> <div class="refsect2" lang="en"> <div class="refsect2" lang="en"><h3><a name="xmlPattern">Structure </a>xmlPattern</h3><pre class="programlisting">struct _xmlPattern {
The content of this structure is not made public by the API. } xmlPattern; </pre><p/> </div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternFlags">Enum </a>xmlPatternFlags</h3><pre class="programlisting">enum <a href="#xmlPatternFlags">xmlPatternFlags</a> { <a name="XML_PATTERN_DEFAULT">XML_PATTERN_DEFAULT</a> = 0 simple pattern match <a name="XML_PATTERN_XPATH">XML_PATTERN_XPATH</a> = 1 standard XPath pattern <a name="XML_PATTERN_XSSEL">XML_PATTERN_XSSEL</a> = 2 /* XPath subset for schema selector */ <a name="XML_PATTERN_XSFIELD">XML_PATTERN_XSFIELD</a> = 4 /* XPath subset for schema field */
}; </pre><p/> </div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternPtr">Typedef </a>xmlPatternPtr</h3><pre class="programlisting"><a href="libxml2-pattern.html#xmlPattern">xmlPattern</a> * xmlPatternPtr;
</pre><p/> </div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamCtxt">Structure </a>xmlStreamCtxt</h3><pre class="programlisting">struct _xmlStreamCtxt {
The content of this structure is not made public by the API. } xmlStreamCtxt; </pre><p/> </div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamCtxtPtr">Typedef </a>xmlStreamCtxtPtr</h3><pre class="programlisting"><a href="libxml2-pattern.html#xmlStreamCtxt">xmlStreamCtxt</a> * xmlStreamCtxtPtr;
</pre><p/> </div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlFreePattern"/>xmlFreePattern ()</h3><pre class="programlisting">void xmlFreePattern (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Free up the memory allocated by @comp</p>
<div class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>an
XSLT
comp</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlFreePatternList"/>xmlFreePatternList ()</h3><pre class="programlisting">void xmlFreePatternList (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Free up the memory allocated by all the elements of
@comp</p> <div class=“variablelist”><table
border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>an
XSLT comp
list</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlFreeStreamCtxt"/>xmlFreeStreamCtxt ()</h3><pre class="programlisting">void xmlFreeStreamCtxt (<a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> stream)<br/>
</pre><p>Free the stream context</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>stream
:</span></td><td>the
stream
context</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternFromRoot"/>xmlPatternFromRoot ()</h3><pre class="programlisting">int xmlPatternFromRoot (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Check if the pattern must be looked at from the
root.</p> <div class=“variablelist”><table
border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>the
precompiled pattern</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>1
if true, 0 if false and -1 in case of
error</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternGetStreamCtxt"/>xmlPatternGetStreamCtxt ()</h3><pre class="programlisting"><a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> xmlPatternGetStreamCtxt (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Get a streaming context for that pattern Use <a
href=“libxml2-pattern.html#xmlFreeStreamCtxt”>xmlFreeStreamCtxt</a>
to free the context.</p> <div class=“variablelist”><table
border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>the
precompiled pattern</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>a
pointer to the context or NULL in case of
failure</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternMatch"/>xmlPatternMatch ()</h3><pre class="programlisting">int xmlPatternMatch (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp, <br/> <a href="libxml2-tree.html#xmlNodePtr">xmlNodePtr</a> node)<br/>
</pre><p>Test whether the node matches the pattern</p>
<div class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>the
precompiled pattern</td></tr><tr><td><span
class=“term”>node
:</span></td><td>a
node</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>1
if it matches, 0 if it doesn't and -1 in case of
failure</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternMaxDepth"/>xmlPatternMaxDepth ()</h3><pre class="programlisting">int xmlPatternMaxDepth (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Check the maximum depth reachable by a
pattern</p> <div class=“variablelist”><table
border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>the
precompiled pattern</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>-2
if no limit (using //), otherwise the depth, and -1 in case of
error</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternMinDepth"/>xmlPatternMinDepth ()</h3><pre class="programlisting">int xmlPatternMinDepth (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Check the minimum depth reachable by a pattern, 0 mean
the / or . are part of the set.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>the
precompiled pattern</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>-1
in case of error otherwise the
depth,</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatternStreamable"/>xmlPatternStreamable ()</h3><pre class="programlisting">int xmlPatternStreamable (<a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> comp)<br/>
</pre><p>Check if the pattern is streamable i.e.
xmlPatternGetStreamCtxt() should work.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>comp
:</span></td><td>the
precompiled pattern</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>1
if streamable, 0 if not and -1 in case of
error.</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlPatterncompile"/>xmlPatterncompile ()</h3><pre class="programlisting"><a href="libxml2-pattern.html#xmlPatternPtr">xmlPatternPtr</a> xmlPatterncompile (const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * pattern, <br/> <a href="libxml2-dict.html#xmlDict">xmlDict</a> * dict, <br/> int flags, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> ** namespaces)<br/>
</pre><p>Compile a pattern.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>pattern
:</span></td><td>the
pattern to compile</td></tr><tr><td><span
class=“term”>dict
:</span></td><td>an
optional dictionary for interned
strings</td></tr><tr><td><span
class=“term”>flags
:</span></td><td>compilation
flags, see <a
href=“libxml2-pattern.html#xmlPatternFlags”>xmlPatternFlags</a></td></tr><tr><td><span
class=“term”>namespaces
:</span></td><td>the
prefix definitions, array of [URI, prefix] or
NULL</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>the
compiled form of the pattern or NULL in case of
error</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamPop"/>xmlStreamPop ()</h3><pre class="programlisting">int xmlStreamPop (<a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> stream)<br/>
</pre><p>push one level from the stream.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>stream
:</span></td><td>the
stream context</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>-1
in case of error, 0
otherwise.</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamPush"/>xmlStreamPush ()</h3><pre class="programlisting">int xmlStreamPush (<a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> stream, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * name, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * ns)<br/>
</pre><p>Push new data onto the stream. NOTE: if the call
xmlPatterncompile() indicated a dictionary, then strings for name and ns
will be expected to come from the dictionary. Both @name and @ns being NULL
means the / i.e. the root of the document. This can also act as a reset.
Otherwise the function will act as if it has been given an
element-node.</p> <div class=“variablelist”><table
border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>stream
:</span></td><td>the
stream context</td></tr><tr><td><span
class=“term”>name
:</span></td><td>the
current name</td></tr><tr><td><span
class=“term”>ns
:</span></td><td>the
namespace name</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>-1
in case of error, 1 if the current state in the stream is a match and 0
otherwise.</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamPushAttr"/>xmlStreamPushAttr ()</h3><pre class="programlisting">int xmlStreamPushAttr (<a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> stream, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * name, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * ns)<br/>
</pre><p>Push new <a
href=“libxml2-SAX.html#attribute”>attribute</a> data onto the
stream. NOTE: if the call xmlPatterncompile() indicated a dictionary, then
strings for name and ns will be expected to come from the dictionary. Both
@name and @ns being NULL means the / i.e. the root of the document. This
can also act as a reset. Otherwise the function will act as if it has been
given an attribute-node.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>stream
:</span></td><td>the
stream context</td></tr><tr><td><span
class=“term”>name
:</span></td><td>the
current name</td></tr><tr><td><span
class=“term”>ns
:</span></td><td>the
namespace name</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>-1
in case of error, 1 if the current state in the stream is a match and 0
otherwise.</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamPushNode"/>xmlStreamPushNode ()</h3><pre class="programlisting">int xmlStreamPushNode (<a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> stream, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * name, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * ns, <br/> int nodeType)<br/>
</pre><p>Push new data onto the stream. NOTE: if the call
xmlPatterncompile() indicated a dictionary, then strings for name and ns
will be expected to come from the dictionary. Both @name and @ns being NULL
means the / i.e. the root of the document. This can also act as a reset.
Different from xmlStreamPush() this function can be fed with nodes of type:
element-, attribute-, text-, cdata-section-, comment- and
processing-instruction-node.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>stream
:</span></td><td>the
stream context</td></tr><tr><td><span
class=“term”>name
:</span></td><td>the
current name</td></tr><tr><td><span
class=“term”>ns
:</span></td><td>the
namespace name</td></tr><tr><td><span
class=“term”>nodeType
:</span></td><td>the
type of the node being
pushed</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>-1
in case of error, 1 if the current state in the stream is a match and 0
otherwise.</td></tr></tbody></table></div></div>
<hr/> <div class="refsect2" lang="en"><h3><a name="xmlStreamWantsAnyNode"/>xmlStreamWantsAnyNode ()</h3><pre class="programlisting">int xmlStreamWantsAnyNode (<a href="libxml2-pattern.html#xmlStreamCtxtPtr">xmlStreamCtxtPtr</a> streamCtxt)<br/>
</pre><p>Query if the streaming pattern additionally needs to
be fed with text-, cdata-section-, comment- and
processing-instruction-nodes. If the result is 0 then only element-nodes
and attribute-nodes need to be pushed.</p> <div
class=“variablelist”><table border=“0”><col
align=“left”/><tbody><tr><td><span
class=“term”>streamCtxt
:</span></td><td>the
stream context</td></tr><tr><td><span
class=“term”>Returns
:</span></td><td>1
in case of need of nodes of the above described types, 0 otherwise. -1 on
API
errors.</td></tr></tbody></table></div></div>
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