1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

     3 <!-- This component and the accompanying materials are made available under the terms of the License 

     4 "Eclipse Public License v1.0" which accompanies this distribution, 

     5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

     9 -->

    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-8C5A65E6-D753-472F-B885-FD0409589036" xml:lang="en"><title>HTTP

    13 Whole Message Filter Example</title><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>The following diagram illustrates the class relationship between the <codeph>MHTTPDataOptimiser</codeph> interface

    15 and the <codeph>RHTTPSession</codeph> class: </p>

    16 <fig id="GUID-25859A19-F3C8-5FBD-B491-C58E5C973424">

    17 <title>              Class relationship between MHTTPDataOptimiser and   

    18           RHTTPSession            </title>

    19 <image href="GUID-9DCAB1DC-D085-576C-A0B9-713E3BF2CAD5_d0e214846_href.png" placement="inline"/>

    20 </fig>

    21 <p>For more information about <xref href="GUID-F34F7481-00CF-3A1B-8D45-D053AD6769A8.dita"><apiname>MHTTPTransactionCallback</apiname></xref>,

    22 see <xref href="GUID-1D32D093-1B7B-5CE8-B57D-5469C1E8E4B9.dita">A simple HTTP Client

    23 session</xref>. </p>

    24 <p>The following code segment illustrates how to define the header file required

    25 for implementing the HTTP Whole Message Filter APIs: </p>

    26 <codeblock id="GUID-1D7FA528-68D6-5AEE-B9F3-CBACC03855AB" xml:space="preserve">#include &lt;http.h&gt;

    27 

    28 class CMyHTTPClient: public CBase,

    29                     public MHTTPTransactionCallback,

    30                     public MHttpDataOptimiser

    31 {

    32 public: // methods from MHTTPTransactionCallback

    33     virtual void MHFRunL(RHTTPTransaction aTransaction, const THTTPEvent& aEvent);

    34     virtual TInt MHFRunError(TInt aError, RHTTPTransaction aTransaction, const THTTPEvent& aEvent);

    35     

    36 public: // methods from MHttpDataOptimiser

    37     virtual void EncodeL (const TDesC8& aHttpData, HBufC8*& aEncodedData);

    38     virtual void DecodeL (const TDesC8& aData, HBufC8*& aHttpData, TBool& aTransFail);

    39 };</codeblock>

    40 <p>The following code segment illustrates how HTTP Whole Message Filter APIs

    41 can be used to enable support for Web Acceleration: </p>

    42 <codeblock id="GUID-2F062305-2D15-534C-8239-FAE4002DB79E" xml:space="preserve">#include "CMyHTTPClient.h"

    43 

    44 //    CMyHTTPClient.cpp

    45 //

    46 //    defines CMyHTTPClient class: CMyHTTPClient

    47 // Literals used in the file

    48 _LIT8(KHttpAuthenticationUrl,        "http://remix.kwed.org");

    49 

    50 

    51 void CMyHTTPClient::CreateTransactionL()

    52     {

    53     TUriParser8 up;

    54     up.Parse(KHttpAuthenticationUrl);

    55 

    56     RHTTPSession session;

    57     RHTTPTransaction trans;

    58     

    59     // Open the HTTP session

    60     session.OpenL();

    61     CleanupClosePushL(session);

    62 

    63     RStringPool strP = session.StringPool();

    64 

    65   //To enable MHTTPDataOptimiser for transaction

    66 

    67     // Open a GET transaction, specifying this object as the request body data supplier

    68     trans = session.OpenTransactionL(up, *this, strP.StringF(HTTP::EGET,RHTTPSession::GetTable()));

    69     CleanupClosePushL(trans);

    70     trans.SetupHttpDataOptimiser(*this);

    71 

    72  trans.SubmitL();

    73     CleanupStack::PopAndDestroy(&trans);

    74     CActiveScheduler::Start();

    75     

    76     CleanupStack::PopAndDestroy(&session); //Closes the session

    77 

    78     }

    79 

    80 TInt CMyHTTPClient::MHFRunError(TInt aError, RHTTPTransaction aTransaction, const THTTPEvent& aEvent)

    81     {

    82     // Handle Error appropriately

    83     }

    84 

    85 void CMyHTTPClient::MHFRunL(RHTTPTransaction aTransaction, const THTTPEvent& aEvent)

    86     {

    87     // Handle events from the framework.

    88     switch (aEvent.iStatus)

    89         {

    90         case KErrHttpOptimiserFailsTrans:

    91             {

    92             INFO_PRINTF1(_L("Cancelling/Failing Transaction\n"));

    93             aTransaction.Fail(THTTPFilterHandle::EProtocolHandler);

    94             } break;

    95 

    96         }

    97     return;

    98     //The following statement is used to eliminate leavescan errors

    99     User::Leave(KErrGeneral);

   100     }

   101 

   102 void CMyHTTPClient::EncodeL (const TDesC8& aHttpData, HBufC8* &aEncodedData)

   103     {

   104     //Provide your own custom encoding implementation

   105     }

   106 

   107 void CMyHTTPClient::DecodeL (const TDesC8& aData, HBufC8*& aHttpData, TBool& aTransFail)

   108     {

   109     //Provide your own custom decoding implementation

   110     }</codeblock>

   111 <p>This code enables the <codeph>MHTTPDataOptimiser</codeph> for a transaction

   112 by using <codeph>RHTTPTransaction::SetupHTTPDataOptimiser()</codeph> and also

   113 illustrates where custom encoding and decoding mechanisms are implemented. </p>

   114 <p> <b>Note:</b> Alternatively, in this code, you can use the following code

   115 segment to enable <codeph>MHTTPDataOptimiser</codeph> for a particular session. </p>

   116 <p> <codeph>session.SetupHttpDataOptimiser(*this); </codeph>  </p>

   117 </conbody></concept>