// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // XPath expression declaration

 //

 /**

  @file

  @publishedAll

  @released

 */

 #ifndef XMLENGXPATHEXPRESSION_H

 #define XMLENGXPATHEXPRESSION_H

 #include <xml/dom/xmlengxpathresult.h>

 #include <xml/dom/xmlengnamespaceresolver.h>

 class TXmlEngNode;

 /**

 A compiled XPath expression is a textual expression transformed after

 syntactical analysis into some internal representation of the expression.  The

 only missing element for evaluation of the expression is evaluation context:

 the context node (where to start) and an optional set of prefix-to-namespace bindings.

 XPath Expressions are created and instantiated by the Evaluator:

 @see TXmlEngXPathEvaluator

 See the XPath spec here:

 http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226/xpath.html

 */

 class RXmlEngXPathExpression

 {

     friend class TXmlEngXPathEvaluator;

 public:

 	/** XPath expression parts */

     enum TXmlEngXPathExpressionPartType

         {

 	    EFunction,

         EPrefix

         };

 public:

     /** Default constructor */

     IMPORT_C RXmlEngXPathExpression();

 	/** Resets the compiled expression and frees the allocated memory */

     IMPORT_C void Destroy();

     /** Resets the compiled expression and frees the allocated memory */

     inline void Close();

 	// XPath 1.0 methods

     /**

     Evaluates this expression.

     @param aContextNode The node relative to which the expression is evaluated.

     @param aResolver Not supported in current API.  Reserved for future use.

     @return Result of evaluation

     @leave KXmlEngErrXPathResult Error evaluating expression

 	@leave KXmlEngErrXPathSyntax Error compiling expression

 	@leave KErrNoMemory Memory allocation error

 	@leave - Otherwise, any of the system wide errors.

     */

     IMPORT_C RXmlEngXPathResult EvaluateL(TXmlEngNode aContextNode, 

                                     const MXmlEngNamespaceResolver* aResolver = NULL) const;

 	// Extensions to XPath 1.0

 	/**

 	Does the same thing as EvaluateL(), but also calculates the dependency list

 	of the expression.

     @param aContextNode The node relative to which the expression is evaluated.

     @param aDependents After the method has returned, contains set of nodes that

     the expression is dependent on.

     @param aResolver Not supported in current API.  Reserved for future use.

     @return Result of evaluation 

     @leave KXmlEngErrXPathResult Error evaluating expression

 	@leave KXmlEngErrXPathSyntax Error compiling expression

 	@leave KErrNoMemory Memory allocation error

 	@leave - Otherwise, any of the system wide errors.

     */

     IMPORT_C RXmlEngXPathResult EvaluateWithDependenciesL(TXmlEngNode aContextNode, 

                                                     RXmlEngNodeSet& aDependents, 

                                                     const MXmlEngNamespaceResolver* aResolver = NULL) const;

 	/**

 	Set context data for the expression currently being evaluated.

 	Extended Context is data set by API users and available for XPath extension

 	functions.  For more information:

 	@see RXmlEngXPathExpression

 	@param aContext Extended context pointer

     */ 

     IMPORT_C void SetExtendedContext(void* aContext);

 	/**

 	Gets extended context data for the expression currently being evaluated.	 

 	@return Extended context pointer or NULL if not sete

 	@see SetExtendedContext

     */ 

     IMPORT_C void* ExtendedContext() const;

 private:

     RXmlEngXPathExpression(void* aData, void* aData2);

 private:

     void* iInternal;

     void* iInternal2;

     TInt32 reserved1; 

     TAny* reserved2; 

 };  

 #include <xml/dom/xmlengxpathexpression.inl>

 #endif /* XMLENGXPATHEXPRESSION_H */