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

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

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

     5 // which accompanies this distribution, and is available

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

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 // XPath expression declaration

    15 //

    16 

    17 

    18 

    19 /**

    20  @file

    21  @publishedAll

    22  @released

    23 */

    24 #ifndef XMLENGXPATHEXPRESSION_H

    25 #define XMLENGXPATHEXPRESSION_H

    26 

    27 #include <xml/dom/xmlengxpathresult.h>

    28 #include <xml/dom/xmlengnamespaceresolver.h>

    29 

    30 class TXmlEngNode;

    31 

    32 /**

    33 A compiled XPath expression is a textual expression transformed after

    34 syntactical analysis into some internal representation of the expression.  The

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

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

    37 

    38 XPath Expressions are created and instantiated by the Evaluator:

    39 @see TXmlEngXPathEvaluator

    40  

    41 See the XPath spec here:

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

    43 */

    44 class RXmlEngXPathExpression

    45 {

    46     friend class TXmlEngXPathEvaluator;

    47 

    48 public:

    49 	/** XPath expression parts */

    50     enum TXmlEngXPathExpressionPartType

    51         {

    52 	    EFunction,

    53         EPrefix

    54         };

    55 

    56 public:

    57     /** Default constructor */

    58     IMPORT_C RXmlEngXPathExpression();

    59 	

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

    61     IMPORT_C void Destroy();

    62     

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

    64     inline void Close();

    65 

    66 	// XPath 1.0 methods

    67 

    68     /**

    69     Evaluates this expression.

    70     

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

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

    73     @return Result of evaluation

    74     @leave KXmlEngErrXPathResult Error evaluating expression

    75 	@leave KXmlEngErrXPathSyntax Error compiling expression

    76 	@leave KErrNoMemory Memory allocation error

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

    78     */

    79     IMPORT_C RXmlEngXPathResult EvaluateL(TXmlEngNode aContextNode, 

    80                                     const MXmlEngNamespaceResolver* aResolver = NULL) const;

    81 

    82 

    83 	// Extensions to XPath 1.0

    84 

    85 	/**

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

    87 	of the expression.

    88     

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

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

    91     the expression is dependent on.

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

    93     @return Result of evaluation 

    94     @leave KXmlEngErrXPathResult Error evaluating expression

    95 	@leave KXmlEngErrXPathSyntax Error compiling expression

    96 	@leave KErrNoMemory Memory allocation error

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

    98     */

    99     IMPORT_C RXmlEngXPathResult EvaluateWithDependenciesL(TXmlEngNode aContextNode, 

   100                                                     RXmlEngNodeSet& aDependents, 

   101                                                     const MXmlEngNamespaceResolver* aResolver = NULL) const;

   102 

   103 	/**

   104 	Set context data for the expression currently being evaluated.

   105 	 

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

   107 	functions.  For more information:

   108 	@see RXmlEngXPathExpression

   109 	 

   110 	@param aContext Extended context pointer

   111     */ 

   112     IMPORT_C void SetExtendedContext(void* aContext);

   113 

   114 	/**

   115 	Gets extended context data for the expression currently being evaluated.	 

   116 	 

   117 	@return Extended context pointer or NULL if not sete

   118 	 

   119 	@see SetExtendedContext

   120     */ 

   121     IMPORT_C void* ExtendedContext() const;

   122     

   123 private:

   124     RXmlEngXPathExpression(void* aData, void* aData2);

   125 

   126 private:

   127     void* iInternal;

   128     void* iInternal2;

   129     TInt32 reserved1; 

   130     TAny* reserved2; 

   131 };  

   132 

   133 #include <xml/dom/xmlengxpathexpression.inl>

   134 

   135 #endif /* XMLENGXPATHEXPRESSION_H */

   136