--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xml/xmldomandxpath/inc/xpath/xmlengxpathevaluationcontext.h	Thu Dec 17 09:29:21 2009 +0200
@@ -0,0 +1,154 @@
+// 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 evaluation context interface
+//
+
+
+
+/**
+ @file
+ @publishedAll
+ @released
+*/
+#ifndef XMLENGXPATHEVALCTXT_H
+#define XMLENGXPATHEVALCTXT_H
+
+#include <xml/dom/xmlengxpathresult.h>
+#include <xml/dom/xmlengelement.h>
+
+/** 
+Provides the XPath evaluation context interface.  An object of this type
+provides the argument values to an extension function to be evalutated 
+and stores the result of evalutation.
+
+@see MXmlEngXPathExtensionFunction
+@see MXmlEngXPathExtensionFunction::Evaluate()
+
+Objects of this type are not registered with the XPath library and must
+be destroyed by their owner.
+
+Any memory allocated by this object must be freed when the object is
+destroyed.
+*/
+class MXmlEngXPathEvaluationContext
+    {
+public:
+    /** 
+    Gets the number of arguments provided.
+    @return The number of arguments provided
+    */
+    virtual TUint ArgCount() = 0;
+
+	/** 
+	Gets an argument by index. Does not transfer ownership. Index starts at 0.
+	@pre 0 <= aIndex < ArgCount().  Function panics if precondition not met.
+    @return The n-th argument of the function
+    */
+    virtual const RXmlEngXPathResult Argument(TUint aIndex) = 0;
+
+    /** 
+    Gets the result written so far.  The result is undefined before SetResult(),
+	InitializeNodeSetResult() or AppendToResult() have been called.
+    
+	@pre SetResult() or InitializeNodeSetResult() and AppendToResult() have
+	been previously called.
+    @return The result evaluated by the function so far.
+    */
+    virtual const RXmlEngXPathResult Result() = 0;
+    
+	/** 
+	Sets the type of result to node set and initializes a new node set.  Any
+	existing result node set is replaced.  
+
+	@see AppendToResult(const TXmlEngNode)
+	@see AppendToResult(const RXmlEngNodeSet)
+	@see AppendToResult(const TXmlEngNamespace, const TXmlEngElement)
+    */ 
+	virtual void InitializeNodeSetResult() = 0;  
+
+	/** 
+	Appends a node to the node set result.  InitializeNodeSetResult() should be
+	called prior to the first call to an AppendToResult() method.
+	
+	This method will return and do nothing if a previous OOM condition in the
+    underlying libxml2 library has not been cleared. See libxml2_modules.h.
+     
+	@pre OOM_FLAG==0, otherwise method returns and does nothing.
+    @param aNode Node to be added
+    */ 
+    virtual void AppendToResult(const TXmlEngNode aNode) = 0;
+
+	/**
+	Appends a namespace node to the node set result.  InitializeNodeSetResult()
+	should be called prior to the first call to an AppendToResult() method.
+
+	A namespace node is the representation of an existing namespace declaration
+	within an element node.  This function cannot be used to add a new namespace
+	declaration, rather it adds an existing namespace declaration attached to
+	aNsParentNode.
+
+	@see TXmlEngNamespace
+
+	This method will return and do nothing if a previous OOM condition in the
+    underlying libxml2 library has not been cleared. See libxml2_modules.h.
+     
+	@pre OOM_FLAG==0, otherwise method returns and does nothing.
+    @param aAppendedNsNode A namspace node to add to the node set result.
+	@param aNsParentNode An element node that holds the namespace declaration
+	represented by aAppendedNsNode.
+    */
+    virtual void AppendToResult(const TXmlEngNamespace aAppendedNsNode, 
+                                const TXmlEngElement aNsParentNode) = 0;
+
+	/** 
+	Appends a node set to the node set result.  Nodes are merged into a
+	resulting node set.  InitializeNodeSetResult() should be called prior to
+	the first call to an AppendToResult() method.
+    
+    This method will return and do nothing if a previous OOM condition in the
+    underlying libxml2 library has not been cleared. See libxml2_modules.h.
+     
+	@pre OOM_FLAG==0, otherwise method returns and does nothing.
+    @param aNodeSet The node set to be appended
+    */
+    virtual void AppendToResult(const RXmlEngNodeSet aNodeSet) = 0;
+    
+	/** 
+	Sets the type of result to floating point number and stores the number as
+	the result.
+    @param aNumber The number to store as the result
+    */ 
+    virtual void SetResult(TReal aNumber) = 0;
+    
+    /** 
+	Sets the type of result to boolean and stores the value as the result.
+    @param aBoolean The value to store as the result
+    */
+    virtual void SetResult(TBool aBoolean) = 0;
+
+    /** 
+	Sets the type of result to string and stores the string as the result.
+    @param aString The string to store as the result
+    */
+    virtual void SetResultL(const TDesC8& aString) = 0;
+    
+    /** 
+    Gets the data specified in RXmlEngXPathExpression::SetExtendedContext() 
+    for the expression currently being evaluated.
+    */    
+    virtual void* ExtendedContext() = 0;
+    };
+
+#endif /* XMLENGXPATHEVALCTXT_H */
+