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

<!-- Copyright (c) 2007-2010 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: 

-->

<!DOCTYPE task

  PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">

<task id="GUID-9477D9DC-7B89-4D60-A7DF-B89411379A52" xml:lang="en"><title>Use

Agent-Specific Commands</title><shortdesc>This is an extension mechanism to allow a client to perform an

agent-specific function. The application needs to know the extended commands

that the agent supports and the format of the input and output buffers used

in the command. All of this is specified by the CAF agent, not the Content

Access Framework.</shortdesc><prolog><metadata><keywords/></metadata></prolog><taskbody>

<prereq>       <p>The manager object must be created using the <xref href="GUID-7F3D9E35-A8FC-35A6-8036-23396BAADFDC.dita#GUID-7F3D9E35-A8FC-35A6-8036-23396BAADFDC/GUID-2F4CB027-777F-3F16-AE9A-8902F4AE87E7"><apiname>CManager::NewL()</apiname></xref> function. </p> 

   </prereq>

<steps id="GUID-4DD07DEC-6017-4237-BE46-1D69E5FBD744-GENID-1-10-1-25-1-1-6-1-5-1-5-1-6-1-4-1-6-1-3-2">

<step id="GUID-9A69E5AD-E938-4092-A8C2-CB65C37C8962-GENID-1-10-1-25-1-1-6-1-5-1-5-1-6-1-4-1-6-1-3-2-1"><cmd>The buffers allow

agent specific objects to be externalized by an application, passed through

CAF and internalized by the agent. The same principle applies for data returned

from the agent to the application.</cmd>

<info><codeblock xml:space="preserve">TInt FancyApplicationFunction(CManager&amp; aManager, CAgent&amp; aAgent, CFancyAgentInputObject&amp; aInputObject, CFancyAgentOutputObject&amp; aOutputObject)

    {

    // Buffer large enough to hold the expected output object 

    TBuf <1000> outputBuffer; 

    // Dynamic buffer to serialize aInputObject 

    CBufFlat* inputBuffer = CBufFlat::NewL(50); 

    CleanupStack::PushL(inputBuffer); 

    RBufWriteStream streamIn(*inputBuffer); 

    CleanupClosePushL(streamIn); 

    // write aInputObject to the dynamic buffer 

    aInputObject.ExternalizeL(streamIn); 

    CleanupStack::PopAndDestroy(&streamIn); 

    // Call the agent specific function #42 

    aManager.AgentSpecificCommand(aAgent, 42 ,inputBuffer->Ptr(0), outputBuffer); 

    // Don't need the input buffer any longer 

    delete *inputBuffer; 

    inputBuffer = NULL; 

    // Create a stream object to read the output buffer             

    RDesReadStream streamOut(outputBuffer); 

    // Build the output object from the output stream 

    aOutputBuffer.InternalizeL(streamOut); 

    }</codeblock></info>

</step>

</steps>

</taskbody><related-links>

<link href="GUID-E99E0092-5F1D-5715-945E-E83C307357C3.dita"><linktext>Managing

CAF Agents</linktext></link>

</related-links></task>