src/xalanc/XPath/XPathEvaluator.hpp - xalan-c - Git at Google

 /*
  * Copyright 1999-2004 The Apache Software Foundation.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 #if !defined(XPATHEVALUATOR_HEADER_GUARD_1357924680)
 #define XPATHEVALUATOR_HEADER_GUARD_1357924680


 #include <xalanc/XPath/XPathDefinitions.hpp>


 #if defined(XALAN_AUTO_PTR_REQUIRES_DEFINITION)
 #include <xalanc/XPath/XObjectFactory.hpp>
 #include <xalanc/XPath/XPathFactoryDefault.hpp>
 #include <xalanc/XPath/XPathConstructionContextDefault.hpp>
 #include <xalanc/XPath/XPathExecutionContextDefault.hpp>
 #endif


 #include <xalanc/Include/XalanAutoPtr.hpp>


 #include <xalanc/XalanDOM/XalanDOMString.hpp>


 XALAN_CPP_NAMESPACE_BEGIN


 #if !defined(XALAN_AUTO_PTR_REQUIRES_DEFINITION)
 class XObjectFactory;
 class XPathFactoryDefault;
 class XPathConstructionContextDefault;
 class XPathExecutionContextDefault;
 #endif


 class DOMSupport;
 class NodeRefList;
 class PrefixResolver;
 class XalanNode;
 class XalanElement;
 class XObjectPtr;
 class XPath;
 class XPathEnvSupport;


 class XALAN_XPATH_EXPORT XPathEvaluator
 {
 public:

 	// Static initializer to be called before any instances are
 	// created.  The call is _not_ thread-safe, you must only call
 	// it once, unless you have called terminate previously, and
 	// you want to re-initialize the library.
 	static void
 	initialize();

 	// Static terminator to be called after all instances
 	// are destroyed.  The call is _not_ thread-safe.  Once
 	// terminated, you can call initialize() again, to
 	// re-initialize the library.
 	static void
 	terminate();


 	XPathEvaluator();

 	~XPathEvaluator();

 	/**
 	 * Evaluate the supplied XPath expression, within the given context.  If
 	 * the expression doesn't select a node, 0 is returned.  If it selects
 	 * more than one node, only the first is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return A pointer to the node selected by the expression, if any.
 	 */
 	XalanNode*
 	selectSingleNode(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const XalanElement*		namespaceNode = 0);

 	/**
 	 * Evaluate the supplied XPath expression, within the given context.  If
 	 * the expression doesn't select a node, 0 is returned.  If it selects
 	 * more than one node, only the first is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return A pointer to the node selected by the expression, if any.
 	 */
 	XalanNode*
 	selectSingleNode(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Evaluate the supplied XPath, within the given context.  If
 	 * the expression doesn't select a node, 0 is returned.  If it selects
 	 * more than one node, only the first is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath A reference to a compiled XPath expression.
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return A pointer to the node selected by the expression, if any.
 	 */
 	XalanNode*
 	selectSingleNode(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const XalanElement*		namespaceNode = 0);

 	/**
 	 * Evaluate the supplied XPath, within the given context.  If
 	 * the expression doesn't select a node, 0 is returned.  If it selects
 	 * more than one node, only the first is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath A reference to a compiled XPath expression.
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return A pointer to the node selected by the expression, if any.
 	 */
 	XalanNode*
 	selectSingleNode(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Evaluate the supplied XPath expression, within the given context.  If
 	 * the expression doesn't select a node, an empty list is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return A list of selected nodes.
 	 */
 	NodeRefList
 	selectNodeList(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const XalanElement*		namespaceNode = 0);

 	/**
 	 * Evaluate the supplied XPath expression, within the given context.  If
 	 * the expression doesn't select a node, an empty list is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return A list of selected nodes.
 	 */
 	NodeRefList
 	selectNodeList(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Evaluate the supplied XPath, within the given context.  If
 	 * the expression doesn't select a node, an empty list is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath A reference to a compiled XPath expression.
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return A list of selected nodes.
 	 */
 	NodeRefList
 	selectNodeList(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const XalanElement*		namespaceNode = 0);

 	/**
 	 * Evaluate the supplied XPath, within the given context.  If
 	 * the expression doesn't select a node, an empty list is returned.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath A reference to a compiled XPath expression.
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return A list of selected nodes.
 	 */
 	NodeRefList
 	selectNodeList(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Evaluate the supplied XPath expression, within the given context.  The
 	 * result is returned as a generalized object.  The object will be
 	 * destroyed when the returned when the user's copy of the returned
 	 * XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
 	 * or another expression is evaluated.
 	 *
 	 * The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
 	 * instance goes out of scope, or another expression is evaluated.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return The result of evaluting the XPath expression.
 	 */
 	XObjectPtr
 	evaluate(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const XalanElement*		namespaceNode = 0);

 	/**
 	 * Evaluate the supplied XPath expression, within the given context.  The
 	 * result is returned as a generalized object.  The object will be
 	 * destroyed when the returned when the user's copy of the returned
 	 * XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
 	 * or another expression is evaluated.
 	 *
 	 * The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
 	 * instance goes out of scope, or another expression is evaluated.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return The result of evaluting the XPath expression.
 	 */
 	XObjectPtr
 	evaluate(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Evaluate the supplied XPath, within the given context.  The
 	 * result is returned as a generalized object.  The object will be
 	 * destroyed when the returned when the user's copy of the returned
 	 * XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
 	 * or another expression is evaluated.
 	 *
 	 * The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
 	 * instance goes out of scope, or another expression is evaluated.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath A reference to a compiled XPath expression.
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return The result of evaluting the XPath expression.
 	 */
 	XObjectPtr
 	evaluate(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const XalanElement*		namespaceNode = 0);

 	/**
 	 * Evaluate the supplied XPath, within the given context.  The
 	 * result is returned as a generalized object.  The object will be
 	 * destroyed when the returned when the user's copy of the returned
 	 * XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
 	 * or another expression is evaluated.
 	 *
 	 * The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
 	 * instance goes out of scope, or another expression is evaluated.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath A reference to a compiled XPath expression.
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return The result of evaluting the XPath expression.
 	 */
 	XObjectPtr
 	evaluate(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Compile an XPath expression into an object which can be used multiple times.
 	 * Call destroyXPath() when finished with the instance.  Otherwise, the object
 	 * will be destroyed when the XPathEvaluator instance goes out of scope.  Since
 	 * no PrefixResolver is supplied, the XPath expression may not contain any
 	 * namespace prefixes.
 	 *
 	 * @param xpathString The XPath expression to evaluate
 	 * @return A pointer to an XPath instance.
 	 */
 	XPath*
 	createXPath(const XalanDOMChar*		xpathString);

 	/**
 	 * Compile an XPath expression into an object which can be used multiple times.
 	 * Call destroyXPath() when finished with the instance.  Otherwise, the object
 	 * will be destroyed when the XPathEvaluator instance goes out of scope.
 	 *
 	 * @param xpathString The XPath expression to evaluate
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param namespaceNode A node to use for namespace prefix resolution.
 	 * @return A pointer to an XPath instance.
 	 */
 	XPath*
 	createXPath(
 			const XalanDOMChar*		xpathString,
 			DOMSupport&				domSupport,
 			const XalanElement*		namespaceNode);

 	/**
 	 * Compile an XPath expression into an object which can be used multiple times.
 	 * Call destroyXPath() when finished with the instance.  Otherwise, the object
 	 * will be destroyed when the XPathEvaluator instance goes out of scope.
 	 *
 	 * @param xpathString The XPath expression to evaluate
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @return A pointer to an XPath instance.
 	 */
 	XPath*
 	createXPath(
 			const XalanDOMChar*		xpathString,
 			const PrefixResolver&	prefixResolver);

 	/**
 	 * Destory a compiled XPath instance.  The instance must have
 	 * been created using createXPath().
 	 *
 	 * @param theXPath The XPath instance to destroy
 	 * @return true if the instance was successfully destroyed
 	 */
 	bool
 	destroyXPath(XPath*		theXPath);

 private:

 	/**
 	 * A helper function to evaluate the supplied XPath expression, within
 	 * the given context.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpathString The XPath expression to evaluate
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @param envSupport The XPathEnvSupport instance to use.
 	 * @return The result of evaluting the XPath expression.
 	 */
 	XObjectPtr
 	evaluate(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XalanDOMChar*		xpathString,
 			const PrefixResolver&	prefixResolver,
 			XPathEnvSupport&		envSupport);

 	/**
 	 * A helper function to evaluate the supplied XPath expression, within
 	 * the given context.
 	 *
 	 * @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
 	 * @param contextNode The source tree context node
 	 * @param xpath The XPath to evaluate
 	 * @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
 	 * @param envSupport The XPathEnvSupport instance to use.
 	 * @return The result of evaluting the XPath expression.
 	 */
 	XObjectPtr
 	evaluate(
 			DOMSupport&				domSupport,
 			XalanNode*				contextNode,
 			const XPath&			xpath,
 			const PrefixResolver&	prefixResolver,
 			XPathEnvSupport&		envSupport);

 	// Data members...
 	const XalanAutoPtr<XObjectFactory>					m_xobjectFactory;

 	const XalanAutoPtr<XPathFactoryDefault>				m_xpathFactory;

 	const XalanAutoPtr<XPathConstructionContextDefault>	m_constructionContext;

 	const XalanAutoPtr<XPathExecutionContextDefault>	m_executionContext;
 };


 XALAN_CPP_NAMESPACE_END


 #endif	// XPATHEVALUATOR_HEADER_GUARD_1357924680
	/*
	* Copyright 1999-2004 The Apache Software Foundation.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	#if !defined(XPATHEVALUATOR_HEADER_GUARD_1357924680)
	#define XPATHEVALUATOR_HEADER_GUARD_1357924680



	#include <xalanc/XPath/XPathDefinitions.hpp>



	#if defined(XALAN_AUTO_PTR_REQUIRES_DEFINITION)
	#include <xalanc/XPath/XObjectFactory.hpp>
	#include <xalanc/XPath/XPathFactoryDefault.hpp>
	#include <xalanc/XPath/XPathConstructionContextDefault.hpp>
	#include <xalanc/XPath/XPathExecutionContextDefault.hpp>
	#endif



	#include <xalanc/Include/XalanAutoPtr.hpp>



	#include <xalanc/XalanDOM/XalanDOMString.hpp>



	XALAN_CPP_NAMESPACE_BEGIN



	#if !defined(XALAN_AUTO_PTR_REQUIRES_DEFINITION)
	class XObjectFactory;
	class XPathFactoryDefault;
	class XPathConstructionContextDefault;
	class XPathExecutionContextDefault;
	#endif



	class DOMSupport;
	class NodeRefList;
	class PrefixResolver;
	class XalanNode;
	class XalanElement;
	class XObjectPtr;
	class XPath;
	class XPathEnvSupport;



	class XALAN_XPATH_EXPORT XPathEvaluator
	{
	public:

	// Static initializer to be called before any instances are
	// created. The call is _not_ thread-safe, you must only call
	// it once, unless you have called terminate previously, and
	// you want to re-initialize the library.
	static void
	initialize();

	// Static terminator to be called after all instances
	// are destroyed. The call is _not_ thread-safe. Once
	// terminated, you can call initialize() again, to
	// re-initialize the library.
	static void
	terminate();


	XPathEvaluator();

	~XPathEvaluator();

	/**
	* Evaluate the supplied XPath expression, within the given context. If
	* the expression doesn't select a node, 0 is returned. If it selects
	* more than one node, only the first is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return A pointer to the node selected by the expression, if any.
	*/
	XalanNode*
	selectSingleNode(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const XalanElement* namespaceNode = 0);

	/**
	* Evaluate the supplied XPath expression, within the given context. If
	* the expression doesn't select a node, 0 is returned. If it selects
	* more than one node, only the first is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return A pointer to the node selected by the expression, if any.
	*/
	XalanNode*
	selectSingleNode(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const PrefixResolver& prefixResolver);

	/**
	* Evaluate the supplied XPath, within the given context. If
	* the expression doesn't select a node, 0 is returned. If it selects
	* more than one node, only the first is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath A reference to a compiled XPath expression.
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return A pointer to the node selected by the expression, if any.
	*/
	XalanNode*
	selectSingleNode(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const XalanElement* namespaceNode = 0);

	/**
	* Evaluate the supplied XPath, within the given context. If
	* the expression doesn't select a node, 0 is returned. If it selects
	* more than one node, only the first is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath A reference to a compiled XPath expression.
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return A pointer to the node selected by the expression, if any.
	*/
	XalanNode*
	selectSingleNode(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const PrefixResolver& prefixResolver);

	/**
	* Evaluate the supplied XPath expression, within the given context. If
	* the expression doesn't select a node, an empty list is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return A list of selected nodes.
	*/
	NodeRefList
	selectNodeList(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const XalanElement* namespaceNode = 0);

	/**
	* Evaluate the supplied XPath expression, within the given context. If
	* the expression doesn't select a node, an empty list is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return A list of selected nodes.
	*/
	NodeRefList
	selectNodeList(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const PrefixResolver& prefixResolver);

	/**
	* Evaluate the supplied XPath, within the given context. If
	* the expression doesn't select a node, an empty list is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath A reference to a compiled XPath expression.
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return A list of selected nodes.
	*/
	NodeRefList
	selectNodeList(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const XalanElement* namespaceNode = 0);

	/**
	* Evaluate the supplied XPath, within the given context. If
	* the expression doesn't select a node, an empty list is returned.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath A reference to a compiled XPath expression.
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return A list of selected nodes.
	*/
	NodeRefList
	selectNodeList(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const PrefixResolver& prefixResolver);

	/**
	* Evaluate the supplied XPath expression, within the given context. The
	* result is returned as a generalized object. The object will be
	* destroyed when the returned when the user's copy of the returned
	* XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
	* or another expression is evaluated.
	*
	* The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
	* instance goes out of scope, or another expression is evaluated.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return The result of evaluting the XPath expression.
	*/
	XObjectPtr
	evaluate(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const XalanElement* namespaceNode = 0);

	/**
	* Evaluate the supplied XPath expression, within the given context. The
	* result is returned as a generalized object. The object will be
	* destroyed when the returned when the user's copy of the returned
	* XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
	* or another expression is evaluated.
	*
	* The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
	* instance goes out of scope, or another expression is evaluated.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return The result of evaluting the XPath expression.
	*/
	XObjectPtr
	evaluate(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const PrefixResolver& prefixResolver);

	/**
	* Evaluate the supplied XPath, within the given context. The
	* result is returned as a generalized object. The object will be
	* destroyed when the returned when the user's copy of the returned
	* XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
	* or another expression is evaluated.
	*
	* The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
	* instance goes out of scope, or another expression is evaluated.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath A reference to a compiled XPath expression.
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return The result of evaluting the XPath expression.
	*/
	XObjectPtr
	evaluate(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const XalanElement* namespaceNode = 0);

	/**
	* Evaluate the supplied XPath, within the given context. The
	* result is returned as a generalized object. The object will be
	* destroyed when the returned when the user's copy of the returned
	* XObjectPtr goes out of scope, or when the XPathEvaluator goes out of scope
	* or another expression is evaluated.
	*
	* The user's XObjectPtr copy _must_ no longer be in scope when the XPathEvaluator
	* instance goes out of scope, or another expression is evaluated.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath A reference to a compiled XPath expression.
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return The result of evaluting the XPath expression.
	*/
	XObjectPtr
	evaluate(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const PrefixResolver& prefixResolver);

	/**
	* Compile an XPath expression into an object which can be used multiple times.
	* Call destroyXPath() when finished with the instance. Otherwise, the object
	* will be destroyed when the XPathEvaluator instance goes out of scope. Since
	* no PrefixResolver is supplied, the XPath expression may not contain any
	* namespace prefixes.
	*
	* @param xpathString The XPath expression to evaluate
	* @return A pointer to an XPath instance.
	*/
	XPath*
	createXPath(const XalanDOMChar* xpathString);

	/**
	* Compile an XPath expression into an object which can be used multiple times.
	* Call destroyXPath() when finished with the instance. Otherwise, the object
	* will be destroyed when the XPathEvaluator instance goes out of scope.
	*
	* @param xpathString The XPath expression to evaluate
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param namespaceNode A node to use for namespace prefix resolution.
	* @return A pointer to an XPath instance.
	*/
	XPath*
	createXPath(
	const XalanDOMChar* xpathString,
	DOMSupport& domSupport,
	const XalanElement* namespaceNode);

	/**
	* Compile an XPath expression into an object which can be used multiple times.
	* Call destroyXPath() when finished with the instance. Otherwise, the object
	* will be destroyed when the XPathEvaluator instance goes out of scope.
	*
	* @param xpathString The XPath expression to evaluate
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @return A pointer to an XPath instance.
	*/
	XPath*
	createXPath(
	const XalanDOMChar* xpathString,
	const PrefixResolver& prefixResolver);

	/**
	* Destory a compiled XPath instance. The instance must have
	* been created using createXPath().
	*
	* @param theXPath The XPath instance to destroy
	* @return true if the instance was successfully destroyed
	*/
	bool
	destroyXPath(XPath* theXPath);

	private:

	/**
	* A helper function to evaluate the supplied XPath expression, within
	* the given context.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpathString The XPath expression to evaluate
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @param envSupport The XPathEnvSupport instance to use.
	* @return The result of evaluting the XPath expression.
	*/
	XObjectPtr
	evaluate(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XalanDOMChar* xpathString,
	const PrefixResolver& prefixResolver,
	XPathEnvSupport& envSupport);

	/**
	* A helper function to evaluate the supplied XPath expression, within
	* the given context.
	*
	* @param domSupport An instance of the corresponding DOMSupport-derived for the DOM implementation being used.
	* @param contextNode The source tree context node
	* @param xpath The XPath to evaluate
	* @param prefixResolver A prefix resolver instance to use for namespace prefix resolution.
	* @param envSupport The XPathEnvSupport instance to use.
	* @return The result of evaluting the XPath expression.
	*/
	XObjectPtr
	evaluate(
	DOMSupport& domSupport,
	XalanNode* contextNode,
	const XPath& xpath,
	const PrefixResolver& prefixResolver,
	XPathEnvSupport& envSupport);

	// Data members...
	const XalanAutoPtr<XObjectFactory> m_xobjectFactory;

	const XalanAutoPtr<XPathFactoryDefault> m_xpathFactory;

	const XalanAutoPtr<XPathConstructionContextDefault> m_constructionContext;

	const XalanAutoPtr<XPathExecutionContextDefault> m_executionContext;
	};



	XALAN_CPP_NAMESPACE_END



	#endif // XPATHEVALUATOR_HEADER_GUARD_1357924680