/*

* Copyright (c) 2002 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:  Http filter for handling dynamic accept headers

*

*/

#ifndef HTTPFILTERACCEPTHEADER_H

#define HTTPFILTERACCEPTHEADER_H

//  INCLUDES

#include <apgcli.h>

#include "httpfilteracceptheaderinterface.h"

const TUint KLanguageBufSize = 256;

class RSharedDataClient;

// CLASS DECLARATION

/**

*  Http filter for handling dynamic accept headers.

*  This filter reads the supported MIME types from the system

*  and constructs the accept headers accordingly. Some optimization

*  is also provided. The filter stores the list of the types in memory 

*  to avoid unnecessary client-server communication to the system.

*

*  The client can also define which subset of the MIME types

*  it needs in the request headers. The following enum defines

*  the parameters that the client can deliver in the transactino

*  properties.

*  <pre>

*

*  typedef enum

*      {

*      EAcceptAll,     

*      EAcceptImages,  

*      EAcceptCss,     

*      EAcceptNone     

*      } ELoadTypes;

*

*  </pre>

*  The filter can be constructed like this:

*  <pre>

*

*    CHttpFilterAcceptHeader* filter = 

*        (CHttpFilterAcceptHeader*) REComSession::CreateImplementationL(

*			 KUidHttpFilterAcceptHeader, 

*			_FOFF(CHttpFilterAcceptHeader, iEcomDtorID),

*			&iSess );

*

*  </pre>

*

*

*  @lib ECOM plugins are not meant to be linked against.

*  @since 2.0

*/

class CHttpFilterAcceptHeader: public CHttpFilterAcceptHeaderInterface, private MHTTPFilter

    {

    public:   // Constructors and destructor

        /**

        * Two-phased constructor.

        */

        static CHttpFilterAcceptHeader* InstallFilterL(TAny* aSession);

        /**

        * Destructor.

        */

        virtual ~CHttpFilterAcceptHeader();

    public:  // Functions from base classes

        // Methods from MHTTPFilterBase

        /**

        * From MHTTPFilterBase. Leaves if error occures. The only possible

        * error can be no memory situation.

        * @since 2.0

        * @param aTransaction An instance of HTTP transaction

        * @param aEvent An instance of THTTPEvent.

        */

        virtual void MHFRunL(

            RHTTPTransaction aTransaction, 

            const THTTPEvent& aEvent);

        /**

        * From MHTTPFilterBase. Empty implementation.

        * @since 2.0

        * @param aEvent An instance of THTTPEvent.

        */

        virtual void MHFSessionRunL(const THTTPSessionEvent& aEvent);

        /**

        * From MHTTPFilterBase. Empty implementation. Not a fatal error so the

        * transaction can continue.

        * @since 2.0

        * @param aTransaction An instance of HTTP transaction

        * @param aEvent An instance of THTTPEvent.

        */

        virtual TInt MHFRunError(TInt aError, RHTTPTransaction aTransaction,

                                 const THTTPEvent& aEvent);

        /**

        * From MHTTPFilterBase. Empty implementation.

        * @since 2.0

        * @param aEvent An instance of THTTPEvent.

        */

        virtual TInt MHFSessionRunError(TInt aError, 

                                        const THTTPSessionEvent& aEvent);

        // Methods from MHTTPFilter

        /**

        * From MHTTPFilter. Deletes itself if the reference 

        * counter reaches zero.

        * @since 2.0

        * @param aEvent An instance of THTTPEvent.

        */

        virtual void MHFUnload(RHTTPSession aSession, 

                               THTTPFilterHandle aHandle);

        /**

        * From MHTTPFilter. Increments the reference counter by one.

        * @since 2.0

        * @param aEvent An instance of THTTPEvent.

        */

        virtual void MHFLoad(RHTTPSession aSession, 

                             THTTPFilterHandle aHandle);

    protected:   // New functions

    protected:   // Functions from base classes

    private:

        /**

        * C++ constructor.

        */

        CHttpFilterAcceptHeader(RHTTPSession* aSession);

        /**

        * Prohibit copy contructor

        */

        CHttpFilterAcceptHeader(const CHttpFilterAcceptHeader&) {};

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

        /**

        * Decide which accept headers must be added to the transaction

        * @since 2.0

        * @param aTransaction An instance of HTTP transaction

        */

        void AddHeadersL(RHTTPTransaction aTransaction);

		/**

		* Add transaction property to inform if we already added

		* all accept headers. This is to avoid adding headers 

		* multiple times in case of redirect.

		*/

		void AllHeadersSetL(RHTTPTransactionPropertySet& aProperties);

        /**

        * Add all supported MIME types

        * @since 2.0

        * @param aHeaders An instance of RHTTPHeaders from the current 

        *        transaction.

        * @param aAcceptStr Ready to use string representing "accept".

        */

        void AddAllHeadersL( RHTTPHeaders& aHeaders, RStringF aAcceptStr );

        /**

        * Add all image MIME types

        * @since 2.5

        * @param aHeaders An instance of RHTTPHeaders from the current 

        *        transaction.

        * @param aAcceptStr Ready to use string representing "accept".

        */

        void AddNpiHeadersL( RHTTPHeaders& aHeaders, RStringF aAcceptStr );

        /**

        * Add all image MIME types

        * @since 2.0

        * @param aHeaders An instance of RHTTPHeaders from the current 

        *        transaction.

        * @param aAcceptStr Ready to use string representing "accept".

        */

        void AddImageHeadersL( RHTTPHeaders& aHeaders, RStringF aAcceptStr );

        /**

        * Add text/css

        * @since 2.0

        * @param aHeaders An instance of RHTTPHeaders from the current 

        *        transaction.

        * @param aAcceptStr Ready to use string representing "accept".

        */

        void AddCssHeadersL( RHTTPHeaders& aHeaders, RStringF aAcceptStr );

        /**

        * CHttpFilterAcceptHeader::AddJavaScriptHeadersL

        * Add "application/x-javascript"

        */

        void AddJavaScriptHeadersL(RHTTPHeaders& aHeaders,RStringF aAcceptStr );

        /**

        * Utility class to actually add a key/value pair to the headers

        * @since 2.0

        * @param aKey RString containing the key sting. E.g. "accept"

        * @param aValue A value for the aKey.

        */

        void SetHeaderL( RHTTPHeaders aHeaders,

                         const RStringF aKey,

                         const TPtrC8& aValue );

        /**

        * Add Language Header based on KHttpAcceptMultipleAcceptLanguagesSupport feature

        * @since 2.6

        * @param aTransaction An instance of HTTP transaction

        */

		void AddLanguageHeaderL(RHTTPTransaction aTransaction);

        /**

        * Add Compose Multiple Languages String

        * @since 2.6

        */

		void ComposeMultipleLanguagesStringL();

        /**

        * Read the featurebitmask from Shared Data

        * @since 2.6

        * @param aSDClient Initialized SharedData client

        */

        void ReadFeatureBitmaskL();

        /**

        * Add hardcoded MIME types that the browser supports itself

        * @since 2.6

        */

        void AddBrowserSupportedTypesL();

        /**

        * Read MIME types for external applications from Shared Data

        * @since 2.6

        * @param aSDClient Initialized SharedData client

        */

        void ReadMimeTypesL();

        /**

        * Add individual entries to MIME type array. Performs

        * white space clean up before adding.

        * @since 2.6

        * @param aPtr A pointer to descriptor containing a mime type

        */

        void AddToArrayL( TPtr8& aPtr );

        /**

        * Parse comma separated list of MIME types and places them to 

        * MIME type array

        * @since 2.6

        * @param aPtr A pointer to descriptor containing a mime type list

        */

        void ParseAndStoreMimeListL( TPtr8& aPtr );

    public:      // Data

    protected:   // Data

    private:     // Data

        TInt iLoadCount;

        RHTTPSession* iSession;

        CDataTypeArray* iDataTypes;

        RStringF iLoadTypeStr;

        RStringF iAcceptStr;

		RStringF iDone;

        TInt     iFeatureBitmask; // Refer HttpFilterAcceptHeaderVariant.hrh for mask definition

		TLanguage iUserSelectedLang;

		RStringF  iUserSelectedLangString;

		TBuf8<KLanguageBufSize> iInstalledLangBuf;

    };

#endif      // CHTTPFILTERACCEPTHEADER_H

// End of File