// 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:

// Result of XPath expression

//

/**

 @file

 @publishedAll

 @released

*/

#ifndef XMLENGXPATHRESULT_H

#define XMLENGXPATHRESULT_H

#include <xml/dom/xmlengnodeset.h>

/**

Represents the result of a XPath expression.

The result may be one of the standard types: string, boolean, number (float), 

node set or be undefined in the case of error.

The returned result should be freed after use.

*/

class RXmlEngXPathResult

{

	friend class RXmlEngXPathExpression;

    friend class TXmlEngXPathEvaluationContextImpl;

public:

    /**

	Result types of a XPath expression.

	See http://w3.org/TR/xpath#section-Introduction

    */

    enum TXmlEngXPathResultType

        {

        EUndefined = 0,

        ENodeset = 1,

        EBoolean = 2,

        ENumber = 3,

        EString = 4

        //Other node types defined in XPath are not supported.

	    } ;

public:

	/** Default constructor */

	IMPORT_C RXmlEngXPathResult();

	/** Frees any allocated memory */

	IMPORT_C void Free();

	/** Frees any allocated memory */

	inline void Close();

	/**

	Retrieves the type of the result (e.g. boolean, number, string, etc.).  

	The type of a result should always be checked before using the result.

	If there was an error and no value was set, undefined is returned.

	Otherwise nodeset is returned.	

	@return Type of result.

	@see TXmlEngXPathResultType

	*/

	IMPORT_C TXmlEngXPathResultType Type() const;

	/**

	Retrieves a node-set result.  A Non-RXmlEngNodeSet result will return NULL.

	No conversion is done from other types.

	For more information no NULL nodes:

	@see TXmlEngNode

	@return Node-set result

	*/

	IMPORT_C RXmlEngNodeSet AsNodeSet() const;

	/**

	Retrieves a string copy of result.

	@param A buffer allocated by the caller that holds the result string

	@leave KErrNoMemory if out of memory situation occurs.

	@leave - Otherwise any of the system wide errors.

	*/	

	IMPORT_C void AsStringL(RBuf8& aOutput) const;

	/**

	Retrieves a numeric value result.  Conversion can occur from other types.

	Node sets, strings, and booleans will be cast to numbers.  Anything else

	will return NAN (i.e. not a number).

	@return Numeric value of the result.

	@see Math

	*/	

	IMPORT_C TReal AsNumber() const;

	/**

	Retrieves a boolean result.  Conversion can occur from other types.

	Numbers will be returned as true unless it is not a number or 0.0.

	A string of 0 length will return false, otherwise true.

	If the node exists it will be returned as true, otherwise false.

	@return Boolean value of the result

	*/	

	IMPORT_C TBool AsBoolean() const;

private:

	/**

	Constructor

	@param aData Internal representation of XPath result

	*/

	RXmlEngXPathResult(void* aData);

private: 

	void* iInternal;

    };	

#include <xml/dom/xmlengxpathresult.inl>

#endif /* XMLENGXPATHRESULT_H */