/*

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

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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:  Misc. libxml2 related utilities.

*

*/

#ifndef XML_UTILS_H

#define XML_UTILS_H

// INCLUDES

#include <e32std.h>

#include <xmlengdom.h>

// CONSTANTS

// MACROS

// DATA TYPES

// FUNCTION PROTOTYPES

// FORWARD DECLARATIONS

class CXmlEncoding;

class CXmlEntity;

class RXmlEngDocument;

class TXmlEngElement;

// CLASS DECLARATION

/**

*  Misc. libxml2 related utilities.

*

*  \b Library: FeedsEngine.lib

*

*  @since 3.0

*/

class CXmlUtils: public CBase

    {

    public: // Constructors and destructor

        /**

        * Two-phased constructor.

        */

        static CXmlUtils* NewL();

        /**

        * Destructor.

        */        

        virtual ~CXmlUtils();

    public:  // New methods

        /**

        * Returns a document from the provided buffer.

        *

        * @since 3.0

        * @param aBuffer A buffer in any char-encoding.

        * @param aCharSet The char-set.

        * @return A document.

        */

        RXmlEngDocument ParseBufferL(const TDesC8& aBuffer,

                const TDesC& aCharSet) const;

        /**

        * Resolves any entities and escaped chars in the given url.

        *

        * @since 3.0

        * @param aUrl The url to clean up.

        * @return void.

        */

        void CleanupUrlL(TDes& aUrl) const;

        /**

        * Remove any markup found in the given descriptor.

        *

        * @since 3.0

        * @param aBuffer The buffer to clean up.

        * @param aNewLineChar The char used to insert a newline.

        * @return ETrue if markup was found in aOrig.

        */

        TBool CleanupMarkupL(TDes& aBuffer, TInt aNewLineChar) const;

        /**

        * Resolves any entities found in aOrig the named entity into its char-value.

        *

        * @since 3.0

        * @param aBuffer The buffer to clean up.

        * @return ETrue if entities were found in aOrig.

        */

        TBool ResolveEntitiesL(TDes& aBuffer) const;

        /**

        * Performs a deep extraction of the text children of the given node.  The result

        * is returned as a 16-bit descriptor.  The char encoding is always ucs2.

        *

        * @since 3.0

        * @param aElement A element.

        * @return The text or NULL.

        */

        HBufC* ExtractTextL(TXmlEngElement aElement) const;

        /**

        * Performs a deep extraction of the text children of the given node.  The result

        * is returned as a 16-bit descriptor.    The char encoding is always ucs2.  This

        * method is different from ExtractTextL in that it doesn't resolve entities or

        * do any other clean up.  It also has a length param.

        *

        * @since 3.1

        * @param aElement A element.

        * @param aMaxLength The max length to extract or 0 to extract the entire string.

        * @param aFromEnd If ETrue the aMaxLength chars are taken from the end of the string.

        * @return The text or NULL.

        */

        HBufC* ExtractSimpleTextL(TXmlEngElement aElement, TInt aMaxLength,

                TBool aFromEnd = EFalse) const;

        /**

        * Returns the first element in the given document.

        *

        * @since 3.0

        * @param aDocument A document.

        * @return A element or NULL-Element.

        */

        TXmlEngElement GetDocumentFirstElement(RXmlEngDocument aDocument) const;

        /**

        * Returns the first child of the given node.

        *

        * @since 3.0

        * @param aElement A element.

        * @return A element or NULL-Element.

        */

        TXmlEngElement GetFirstElementChild(TXmlEngElement aElement) const;

        /**

        * Returns the first child of the given node with the provided name.  aUtf8Name

        * MUST be null terminated.

        *

        * @since 3.0

        * @param aElement A element.

        * @param aName The name of the node.

        * @return A element or NULL-Element.

        */

        TXmlEngElement GetFirstNamedChild(TXmlEngElement aElement, const TDesC8& aUtf8Name) const;

        /**

        * Returns the next sibling of the given node.

        *

        * @since 3.0

        * @param aNode A element.

        * @return A element or NULL-Element.

        */

        TXmlEngElement GetNextSiblingElement(TXmlEngElement aElement);

        /**

        * Returns true if the given node has a name of aName.  This method doesn't 

        * compare the namespace.

        *

        * @since 3.0

        * @param aElement A element.

        * @param aName The name of the node.

        * @return ETrue if they match.

        */

        TBool IsNamed(TXmlEngElement aElement, const TDesC8& aUtf8Name) const;

        /**

        * Returns true if the given node has match the given namespace and name.

        *

        * @since 3.0

        * @param aElement A element.

        * @param aNameSpace The namespace of the node.

        * @param aName The name of the node.

        * @return ETrue if they match.

        */

        TBool IsNamed(TXmlEngElement aElement, const TDesC8& aUtf8NameSpace, 

                const TDesC8& aUtf8Name) const;

        /**

        * Returns the attribute's value or NULL if the attribute wasn't present.

        *

        * @since 3.0

        * @param aElement A element.

        * @param aAttribute The attribute to extract.

        * @return The value or NULL.

        */

        HBufC* AttributeL(TXmlEngElement aElement, const TDesC8& aAttribute) const;

    private:  // New methods

        /**

        * C++ default constructor.

        */

        CXmlUtils();

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

        /**

        * Cleanup stack callback method to cleanup ParseBufferL.

        *

        * @since 3.0

        * @param aPtr A libxml2 parser context ptr.

        * @return void.

        */

        static void CleanupParseBuffer(TAny *aPtr);

        /**

        * Skip any chars before the XML-prolog.

        *

        * @since 3.0

        * @param aBuffer A xml buffer.

        * @param aLen The length of the xml buffer.

        * @return void.

        */

        void SkipCharsBeforeXmlProlog(const TUint8** aString, TInt& aLen) const;

        /**

        * Remove any markup found in the given descriptor.

        *

        * @since 3.0

        * @param aBuffer The string to be stripped of markup.

        * @param aNewLineChar The char used to insert a newline.

        * @return ETrue if markup was found in aBuffer.

        */

        TBool StripMarkupL(TDes& aBuffer, TInt aNewLineChar) const;        

        /**

        * Remove any CDATA markers in the given descriptor.

        *

        * @since 3.1

        * @param aBuffer The string to be stripped of markup.

        * @return ETrue if CDATA markers were found in aBuffer.

        */

        TBool StripCDataMarkers(TDes& aBuffer) const;

    private:  // Data

        TLeakTracker  iLeakTracker;

        RXmlEngDOMImplementation iImpl;

        CXmlEncoding*  iXmlEncoding;

        CXmlEntity*    iXmlEntity;

    };

#endif      // XML_UTILS_H

// End of File