/*

* Copyright (c) 2002-2005 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:        This abstract class defines the interface for WSF XML

*                fragment classes.

*

*/

#ifndef M_SEN_FRAGMENT_H

#define M_SEN_FRAGMENT_H

//  INCLUDES

#include <e32base.h>

#include <s32strm.h>

#include <xml/attribute.h>

#include <SenXmlReader.h>

#include <MSenElement.h>

// FORWARD DECLARATIONS

class CSenElement;

using namespace Xml;

// CLASS DECLARATION

/**

*  This abstract class defines the interface for XML fragment classes.

*  The subclasses are used to extract certain part of XML document into

*  a separate XML subtree, called fragment. This M-class is typically used

*  when a safe reference to some actual implementation is required.

*  Fragment classes are content handlers for SAX callback events received

*  from CSenXmlReader class. They typically inherit MSenContentHandlerClient

*  to achive this.

*  @lib SenXML.dll

*  @since Series60 3.0

*/

class MSenFragment

    {

    public: // New functions

        /**

         *  Getting the fragment as an XML element. This method will panic if 

         *  element has not been initialized (EFragmentElementNotInitialized).

         *  @since Series60 3.0

         *  @return the current object as element. Ownership is not transferred.

         */

        virtual CSenElement& AsElement() = 0;

        /**

         *  Method extracts the root element (whole data) from this fragment.

         *  After calling this method, the fragment does not have any

         *  internal element. Method is often called before fragment is

         *  destroyed, in order to fetch its content and transfer ownership

         *  to that content to some other object.

         *  @since Series60 3.0

         *  @return the current object as element. May return NULL.

         *          Ownership is transferred to the caller.

         */

        virtual CSenElement* ExtractElement() = 0;

        /**

         *  Sets the XML reader to be used for parsing for the fragment.

         *  @since Series60 3.0

         *  @param aReader:     the reader to be used. 

         *                      Ownership is NOT transferred.

         */

        virtual void SetReader(CSenXmlReader& aReader) = 0;

        /**

         *  Gets the XML reader which this fragment uses for parsing.

         *  @since Series60 3.0

         *  @param aReader:     the reader to be used. 

         *                      Ownerships is not transferred.

         *                      May return NULL.

         */

        virtual CSenXmlReader* Reader() = 0;

        /**

         *  Method to invoke parsing of a UTF-8 form XML data.

         *  Note that SetReader() must be called before this 

         *  method can be used.

         *  Parsing is dependent of preset localname or qualifiedname

         *  and possible namespace for this fragment.

         *  @since Series60 3.0

         *  @param aBuf:    The XML to be parsed.

         */

        virtual void ParseL(const TDesC8& aBuf) = 0;

        /**

         *  Same as ParseL() except that it doesn't leave in case of an error. 

         *  Instead errors are trapped and error is returned.

         *  SetReader() must be called before this method can be used.

         *  @since Series60 3.0

         *  @param aBuf:    The XML to be parsed.

         *  @return KErrNone or other system-wide Symbian error codes

         */

        virtual TInt BuildFrom(const TDesC8& aBuf) = 0;

        /**

         *  Let the delegate MSenFragment handle the following SAX events.

         *  This fragment is made the owner of the delegate and the delegate

         *  is expected to make this MSenFragment the receiver of SAX events

         *  once it has seen the end element for itself. This is achieved by

         *  ResumeParsingFromL(), which delegate will call from his parent.

         *  The currently set XML reader is used to parse XML for the delagate,

         *  too.

         *  @since Series60 3.0

         *  @param aDelegate:   the fragment to start handling the SAX events.

         */

        virtual void DelegateParsingL(MSenFragment& aDelegate) = 0;

        /**

         *  Creates a new delegate (fragment) using the given arguments

         *  and lets it handle the SAX events according

         *  to given localname (or qualifiedname) and possible namespace.

         *  This instance is made the owner of the delegate and the delegate 

         *  is expected to resume parsing to this MSenFragment after it has

         *  finished handling the dedicated part of XML document in question.

         *  at the EndElementL().

         *  The currently set XML reader is used to parse XML for the delagate,

         *  too.

         *  @since Series60 3.0

         *  @param aNsUri:      the namespace URI of the new delegate

         *  @param aLocalName:  the local name of the new delegate

         *  @param aQName:      the qualified name of the new delegate

         *  @param aAttrs:      the attributes which to be set for the new delegate

         */

        virtual void DelegateParsingL(  const TDesC8& aNsUri,

                                        const TDesC8& aLocalName,

                                        const TDesC8& aQName,

                                        const RAttributeArray& aAttrs) = 0;

        /**

         *  Method sets the reader for this fragment and sets this to be the 

         *  content handler for the SAX events according to preset localname

         *  (or qualifiedname) and possible namespace.

         *  @since Series60 3.0

         *  @param aReader: Reader to be used.

         */

        virtual void ParseWithL(CSenXmlReader& aReader) = 0;

        /**

         *  Sets a new owner (parent) for this fragment.

         *  @since Series60 3.0

         *  @param aFragment:   the new parent.

         */

        virtual void SetOwner(MSenFragment& aFragment) = 0;

        /**

         *  Resumes the parsing. Usually called by some delegate 

         *  fragment which was parsing itself through DelegateParsingL()

         *  call from this instance.

         *  @since Series60 3.0

         *  @param aNsUri       The namespace URI of the current element

         *  @param aLocalName   The local name of the current element

         *  @param aQName       The qualified name of the current element

         */

        virtual void ResumeParsingFromL(const TDesC8& aNsUri,

                                        const TDesC8& aLocalName,

                                        const TDesC8& aQName) = 0;

        /**

         *  Sets the attributes for the fragment.

         *  @since Series60 3.0

         *  @param aAttrs:  the array of attributes.

         */

        virtual void SetAttributesL(const RAttributeArray& aAttrs) = 0;

        /**

         *  Writes the start element tag to the content stream. 

         *  Subclasses typically override this.

         *  @since Series60 3.0

         *  @param aNsUri       The namespace URI of the current element

         *  @param aLocalName   The local name of the current element

         *  @param aQName       The qualified name of the current element

         *  @param aAttrs:  the array of attributes.

         */

        virtual void WriteStartElementL(const TDesC8& aNsUri,

                                        const TDesC8& aLocalName,

                                        const TDesC8& aQName,

                                        const RAttributeArray& aAttrs) = 0;

        /**

         *  Writes the end element tag to the content stream. 

         *  Subclasses typically override this

         *  @since Series60 3.0

         *  @param aNsUri       The namespace URI of the current element

         *  @param aLocalName   The local name of the current element

         *  @param aQName       The qualified name of the current element

         */

        virtual void WriteEndElementL(const TDesC8& aNsUri,

                                      const TDesC8& aLocalName,

                                      const TDesC8& aQName) = 0;

        /**

        *   Getter for fragment XML local name.

        *   @since Series60 3.0

        *   @return localname or KNullDesC8 if not set.

        */

        virtual const TDesC8& LocalName() const = 0;

        /**

        *   Getter for fragment XML namespace URI.

        *   @since Series60 3.0

        *   @return namespace URI or KNullDesC8 if not set.

        */

        virtual const TDesC8& NsUri() const = 0;

        /**

         *  Getter for XML namespace prefix of this fragment.

         *  @since Series60 3.0

         *  @return namespace prefix or KNullDesC8 if not set.

         */

        virtual const TDesC8& NsPrefix() const = 0;

        /**

         *  Fragment writes itself to a write stream using UTF-8 encoding.

         *  @since Series60 3.0

         *  @param aWriteStream:    The stream to write to.

         */

        virtual void WriteAsXMLToL(RWriteStream& aWriteStream) = 0;

        /**

         *  Gets the fragment as Unicode (UCS-2) form XML. 

         *  @since Series60 3.0

         *  @return fragment as XML. Caller takes ownership.

         */

        virtual HBufC* AsXmlUnicodeL() = 0;

        /**

         *  Gets the fragment as a UTF-8 form XML.

         *  @since Series60 3.0

         *  @return fragment as XML. Caller takes ownership.

         */

        virtual HBufC8* AsXmlL() = 0;

        /**

         * Checks if fragment matches to another fragment by its content and 

         * child elements. Fragment can contain more data than the given 

         * candidate.

         * @since Series60 3.0

         * @param aCandidate    The pattern to be matched. Must contain same or 

         *                      less data for match to come true.

         * @return ETrue if content and possible children match exactly 

         *          to given pattern. EFalse otherwise.

         */

        virtual TBool ConsistsOfL(MSenFragment& aCandidate) = 0;

    };

#endif // M_SEN_FRAGMENT_H

// End of File