📄 libxml2-xpath.html
字号:
<?xml version="1.0" encoding="UTF-8"?><html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>xpath: XML Path Language implementation</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-xmlwriter.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-xpathInternals.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">xpath</span> </h2> <p>xpath - XML Path Language implementation</p> <p>API for the XML Path Language implementation XML Path Language implementation XPath is a language for addressing parts of an XML document, designed to be used by both XSLT and XPointer</p> <p>Author(s): Daniel Veillard </p> <div class="refsynopsisdiv"> <h2>Synopsis</h2> <pre class="synopsis">#define <a href="#xmlXPathNodeSetGetLength">xmlXPathNodeSetGetLength</a>(ns);#define <a href="#XML_XPATH_CHECKNS">XML_XPATH_CHECKNS</a>;#define <a href="#XML_XPATH_NOVAR">XML_XPATH_NOVAR</a>;#define <a href="#xmlXPathNodeSetItem">xmlXPathNodeSetItem</a>(ns, index);#define <a href="#xmlXPathNodeSetIsEmpty">xmlXPathNodeSetIsEmpty</a>(ns);typedef enum <a href="#xmlXPathObjectType">xmlXPathObjectType</a>;typedef <a href="libxml2-xpath.html#xmlXPathVariable">xmlXPathVariable</a> * <a href="#xmlXPathVariablePtr">xmlXPathVariablePtr</a>;typedef struct _xmlXPathContext <a href="#xmlXPathContext">xmlXPathContext</a>;typedef enum <a href="#xmlXPathError">xmlXPathError</a>;typedef struct _xmlXPathFunct <a href="#xmlXPathFunct">xmlXPathFunct</a>;typedef <a href="libxml2-xpath.html#xmlXPathType">xmlXPathType</a> * <a href="#xmlXPathTypePtr">xmlXPathTypePtr</a>;typedef struct _xmlXPathType <a href="#xmlXPathType">xmlXPathType</a>;typedef <a href="libxml2-xpath.html#xmlNodeSet">xmlNodeSet</a> * <a href="#xmlNodeSetPtr">xmlNodeSetPtr</a>;typedef <a href="libxml2-xpath.html#xmlXPathFunct">xmlXPathFunct</a> * <a href="#xmlXPathFuncPtr">xmlXPathFuncPtr</a>;typedef <a href="libxml2-xpath.html#xmlXPathCompExpr">xmlXPathCompExpr</a> * <a href="#xmlXPathCompExprPtr">xmlXPathCompExprPtr</a>;typedef struct _xmlXPathObject <a href="#xmlXPathObject">xmlXPathObject</a>;typedef struct _xmlXPathCompExpr <a href="#xmlXPathCompExpr">xmlXPathCompExpr</a>;typedef <a href="libxml2-xpath.html#xmlXPathContext">xmlXPathContext</a> * <a href="#xmlXPathContextPtr">xmlXPathContextPtr</a>;typedef <a href="libxml2-xpath.html#xmlXPathParserContext">xmlXPathParserContext</a> * <a href="#xmlXPathParserContextPtr">xmlXPathParserContextPtr</a>;typedef struct _xmlNodeSet <a href="#xmlNodeSet">xmlNodeSet</a>;typedef struct _xmlXPathVariable <a href="#xmlXPathVariable">xmlXPathVariable</a>;typedef <a href="libxml2-xpath.html#xmlXPathObject">xmlXPathObject</a> * <a href="#xmlXPathObjectPtr">xmlXPathObjectPtr</a>;typedef struct _xmlXPathAxis <a href="#xmlXPathAxis">xmlXPathAxis</a>;typedef <a href="libxml2-xpath.html#xmlXPathAxis">xmlXPathAxis</a> * <a href="#xmlXPathAxisPtr">xmlXPathAxisPtr</a>;typedef struct _xmlXPathParserContext <a href="#xmlXPathParserContext">xmlXPathParserContext</a>;int <a href="#xmlXPathCastNodeSetToBoolean">xmlXPathCastNodeSetToBoolean</a> (<a href="libxml2-xpath.html#xmlNodeSetPtr">xmlNodeSetPtr</a> ns);typedef <a href="libxml2-xpath.html#xmlXPathFunction">xmlXPathFunction</a> <a href="#xmlXPathFuncLookupFunc">xmlXPathFuncLookupFunc</a> (void * ctxt, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * name, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * ns_uri);<a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * <a href="#xmlXPathCastNodeToString">xmlXPathCastNodeToString</a> (<a href="libxml2-tree.html#xmlNodePtr">xmlNodePtr</a> node);int <a href="#xmlXPathIsNaN">xmlXPathIsNaN</a> (double val);int <a href="#xmlXPathContextSetCache">xmlXPathContextSetCache</a> (<a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctxt, <br/> int active, <br/> int value, <br/> int options);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathConvertString">xmlXPathConvertString</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);int <a href="#xmlXPathCompiledEvalToBoolean">xmlXPathCompiledEvalToBoolean</a> (<a href="libxml2-xpath.html#xmlXPathCompExprPtr">xmlXPathCompExprPtr</a> comp, <br/> <a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctxt);int <a href="#xmlXPathIsInf">xmlXPathIsInf</a> (double val);long <a href="#xmlXPathOrderDocElems">xmlXPathOrderDocElems</a> (<a href="libxml2-tree.html#xmlDocPtr">xmlDocPtr</a> doc);<a href="libxml2-xpath.html#xmlNodeSetPtr">xmlNodeSetPtr</a> <a href="#xmlXPathNodeSetCreate">xmlXPathNodeSetCreate</a> (<a href="libxml2-tree.html#xmlNodePtr">xmlNodePtr</a> val);double <a href="#xmlXPathCastBooleanToNumber">xmlXPathCastBooleanToNumber</a> (int val);double <a href="#xmlXPathCastNodeToNumber">xmlXPathCastNodeToNumber</a> (<a href="libxml2-tree.html#xmlNodePtr">xmlNodePtr</a> node);double <a href="#xmlXPathCastStringToNumber">xmlXPathCastStringToNumber</a> (const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * val);typedef <a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathAxisFunc">xmlXPathAxisFunc</a> (<a href="libxml2-xpath.html#xmlXPathParserContextPtr">xmlXPathParserContextPtr</a> ctxt, <br/> <a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> cur);double <a href="#xmlXPathCastToNumber">xmlXPathCastToNumber</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);int <a href="#xmlXPathCastStringToBoolean">xmlXPathCastStringToBoolean</a> (const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * val);<a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * <a href="#xmlXPathCastNumberToString">xmlXPathCastNumberToString</a> (double val);typedef <a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathVariableLookupFunc">xmlXPathVariableLookupFunc</a> (void * ctxt, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * name, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * ns_uri);void <a href="#xmlXPathFreeObject">xmlXPathFreeObject</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> obj);int <a href="#xmlXPathEvalPredicate">xmlXPathEvalPredicate</a> (<a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctxt, <br/> <a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> res);void <a href="#xmlXPathFreeContext">xmlXPathFreeContext</a> (<a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctxt);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathObjectCopy">xmlXPathObjectCopy</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);void <a href="#xmlXPathFreeNodeSetList">xmlXPathFreeNodeSetList</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> obj);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathEval">xmlXPathEval</a> (const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * str, <br/> <a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctx);<a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * <a href="#xmlXPathCastNodeSetToString">xmlXPathCastNodeSetToString</a> (<a href="libxml2-xpath.html#xmlNodeSetPtr">xmlNodeSetPtr</a> ns);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathCompiledEval">xmlXPathCompiledEval</a> (<a href="libxml2-xpath.html#xmlXPathCompExprPtr">xmlXPathCompExprPtr</a> comp, <br/> <a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctx);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathEvalExpression">xmlXPathEvalExpression</a> (const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * str, <br/> <a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctxt);void <a href="#xmlXPathInit">xmlXPathInit</a> (void);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathConvertBoolean">xmlXPathConvertBoolean</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);typedef int <a href="#xmlXPathConvertFunc">xmlXPathConvertFunc</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> obj, <br/> int type);typedef void <a href="#xmlXPathFunction">xmlXPathFunction</a> (<a href="libxml2-xpath.html#xmlXPathParserContextPtr">xmlXPathParserContextPtr</a> ctxt, <br/> int nargs);int <a href="#xmlXPathCmpNodes">xmlXPathCmpNodes</a> (<a href="libxml2-tree.html#xmlNodePtr">xmlNodePtr</a> node1, <br/> <a href="libxml2-tree.html#xmlNodePtr">xmlNodePtr</a> node2);<a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * <a href="#xmlXPathCastToString">xmlXPathCastToString</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);<a href="libxml2-xpath.html#xmlXPathCompExprPtr">xmlXPathCompExprPtr</a> <a href="#xmlXPathCtxtCompile">xmlXPathCtxtCompile</a> (<a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> ctxt, <br/> const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * str);typedef void <a href="#xmlXPathEvalFunc">xmlXPathEvalFunc</a> (<a href="libxml2-xpath.html#xmlXPathParserContextPtr">xmlXPathParserContextPtr</a> ctxt, <br/> int nargs);<a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * <a href="#xmlXPathCastBooleanToString">xmlXPathCastBooleanToString</a> (int val);int <a href="#xmlXPathCastNumberToBoolean">xmlXPathCastNumberToBoolean</a> (double val);void <a href="#xmlXPathFreeNodeSet">xmlXPathFreeNodeSet</a> (<a href="libxml2-xpath.html#xmlNodeSetPtr">xmlNodeSetPtr</a> obj);void <a href="#xmlXPathFreeCompExpr">xmlXPathFreeCompExpr</a> (<a href="libxml2-xpath.html#xmlXPathCompExprPtr">xmlXPathCompExprPtr</a> comp);<a href="libxml2-xpath.html#xmlXPathContextPtr">xmlXPathContextPtr</a> <a href="#xmlXPathNewContext">xmlXPathNewContext</a> (<a href="libxml2-tree.html#xmlDocPtr">xmlDocPtr</a> doc);<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> <a href="#xmlXPathConvertNumber">xmlXPathConvertNumber</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);<a href="libxml2-xpath.html#xmlXPathCompExprPtr">xmlXPathCompExprPtr</a> <a href="#xmlXPathCompile">xmlXPathCompile</a> (const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> * str);double <a href="#xmlXPathCastNodeSetToNumber">xmlXPathCastNodeSetToNumber</a> (<a href="libxml2-xpath.html#xmlNodeSetPtr">xmlNodeSetPtr</a> ns);int <a href="#xmlXPathCastToBoolean">xmlXPathCastToBoolean</a> (<a href="libxml2-xpath.html#xmlXPathObjectPtr">xmlXPathObjectPtr</a> val);</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="XML_XPATH_CHECKNS">Macro </a>XML_XPATH_CHECKNS</h3><pre class="programlisting">#define <a href="#XML_XPATH_CHECKNS">XML_XPATH_CHECKNS</a>;</pre><p>check namespaces at compilation</p></div> <hr/> <div class="refsect2" lang="en"><h3><a name="XML_XPATH_NOVAR">Macro </a>XML_XPATH_NOVAR</h3><pre class="programlisting">#define <a href="#XML_XPATH_NOVAR">XML_XPATH_NOVAR</a>;</pre><p>forbid variables in expression</p></div> <hr/> <div class="refsect2" lang="en"><h3><a name="xmlXPathNodeSetGetLength">Macro </a>xmlXPathNodeSetGetLength</h3><pre class="programlisting">#define <a href="#xmlXPathNodeSetGetLength">xmlXPathNodeSetGetLength</a>(ns);</pre><p>Implement a functionality similar to the DOM NodeList.length. Returns the number of nodes in the node-set.</p><div class="variablelist"><table border="0"><col align="left"/><tbody><tr><td><span class="term"><i><tt>ns</tt></i>:</span></td><td>a node-set</td></tr></tbody></table></div></div>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -