Symbian3/PDK/Source/GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita
author Dominic Pinkman <Dominic.Pinkman@Nokia.com>
Tue, 30 Mar 2010 11:56:28 +0100
changeset 5 f345bda72bc4
parent 3 46218c8b8afa
child 14 578be2adaf3e
permissions -rw-r--r--
Week 12 contribution of PDK documentation_content. See release notes for details. Fixes Bug 2054, Bug 1583, Bug 381, Bug 390, Bug 463, Bug 1897, Bug 344, Bug 1319, Bug 394, Bug 1520, Bug 1522, Bug 1892"

<?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 concept
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C" xml:lang="en"><title>Supplier
API Tutorial </title><shortdesc>The Supplier API handles the delivery and transformation of Digital
Rights Management (DRM) protected content. It transforms imported DRM content
in a device into a secure format for storage. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>Supplier API comprises of <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CSupplier</apiname></xref> and <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CImportFile</apiname></xref>. </p>
<section id="GUID-17D59A99-1491-513C-BC41-BB4ECA22B931"><title>Introduction</title> <p>The
Supplier API allows Content Access (CA) agents to publish the supported content
MIME types that can be handled by Content Access Framework (CAF). When a file
arrive on a device (for example, through a browser), applications check for
its MIME types and import the file into CAF. The agent transforms the file
into a secure format for using it in the device. </p> <p>The transformation
may not be required because the files arrive in a format fit for use in the
device. However, some agents might require to protect (encrypt) the content
at the moment it arrives, and Supplier API manages this protection. </p> </section>
<section><title>Procedure</title><p>The following steps illustrate how to
use Supplier API: </p> <ol id="GUID-A2CD1699-28D5-530C-9552-59277385E353">
<li id="GUID-DF9A5E76-B282-568C-A5A1-654A88698B0B"><p><xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita#GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C/GUID-7501DF89-76B6-52A2-AD3A-6391832F3C5A">Start a new import session</xref>  </p> </li>
<li id="GUID-2E539668-4A7B-5F55-83D2-1A092ECBCE7E"><p><xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita#GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C/GUID-74C3F4CF-2D85-568D-B935-B93E1F857F78">Prepare to import a file</xref>  </p> </li>
<li id="GUID-CAAA7C49-B8FD-51CF-9973-2676B3E01837"><p><xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita#GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C/GUID-4023F3AD-6CA3-59E3-8148-F9D76480A05E">Import the file</xref>  </p> </li>
<li id="GUID-5D182213-F5AF-5052-BDB4-D940F61BCDFA"><p><xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita#GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C/GUID-52D00B05-3EB5-5C10-A3BC-8AC12B968FF0">Transfer the file to the Content Access Agent</xref>  </p> </li>
<li id="GUID-3078BA87-4D9D-5707-8F7F-107EFD372CD0"><p><xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita#GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C/GUID-5436E5BC-793C-5373-B9A9-404D6ECC2EBA">Complete the import</xref>  </p> </li>
<li id="GUID-A74B75B3-3A21-5BC0-A24C-186A915C5EAC"><p><xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita#GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C/GUID-EDAB286B-FBC9-5DAF-A466-7B07F2A2FC29"> Check the output file, if necessary</xref>. </p> </li>
</ol> </section>
<section id="GUID-7501DF89-76B6-52A2-AD3A-6391832F3C5A"><title>Start a new
import session</title> <p>Use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CSupplier</apiname></xref> to
import files into CAF. </p> <p>Create an instance of <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CSupplier</apiname></xref> to
start an import session and set the output path according to an application's
requirements. </p> <codeblock id="GUID-BCD346E6-9077-546A-81DA-E4CE1706CB88" xml:space="preserve">// Create Supplier 
CSupplier *mySupplier = CSupplier::NewL(); 

// Set output path for DRM protected content 
_LIT(KPath,"C:\\myOutputFiles");
mySupplier-&gt;SetOutputDirectoryL(KPath());</codeblock><note><ul>
<li id="GUID-25C5C79D-B6C9-59FE-82D7-A5A04950D94A"><p>It is not necessary
to set the output path if the application provides output file handles to
the CA agent. </p> </li>
<li id="GUID-B4029DD4-9A76-5647-9DBB-18A2D64E6089"><p> <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CSupplier</apiname></xref> uses
its <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CAgentResolver</apiname></xref> member
to determine which CA agent must be used to import each file. For more information,
see <xref href="GUID-9993D750-9116-55B2-812A-7A92C50F467F.dita">Apparc Recognizer
for CAF</xref>. </p> </li>
</ul></note> </section>
<section id="GUID-74C3F4CF-2D85-568D-B935-B93E1F857F78"><title>Prepare to
import the file</title> <p>Preparing to import a DRM protected file includes
the following steps: </p> <ol id="GUID-5EEA53C8-1B3F-50A9-8C22-8D61B11CE28B">
<li id="GUID-960C7AB2-5241-521C-BBBE-5B09294F43C0"><p>Checking for supported
MIME types </p> </li>
<li id="GUID-C949EF2E-7B80-5E30-9D0A-AD912579E595"><p>Creating a <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CMetaDataList</apiname></xref> object </p> </li>
</ol> <p><b>Checking for supported MIME types</b> </p> <p>Before importing
a file into the content access framework, an application must check if the
MIME type of the file is supported. Each agent publishes a list of supported
MIME types and the list is configured in the agent's resource file. Use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CSupplier::IsImportSupported()</apiname></xref> to
check the list of supported MIME type of files. </p> <codeblock id="GUID-EB6353F1-D53C-578A-BE4C-B569C4719960" xml:space="preserve">if(!mySupplier-&gt;IsImportSupported(myMimeType)) 
    { 
    return; 
    }</codeblock> <p><b>Creating a CMetaDataList object </b> </p> <p>The <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CMetaDataList</apiname></xref> object stores information
associated with an import file, and it is passed to the CA agent. For example,
OMA DRM 1.0 files might contain HTTP header<codeph>              X-Oma-Drm-Separate-Delivery</codeph>,
which informs the agent about the time duration within which rights are expected
for the content. </p> <p>The following code snippet shows creating a <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CMetaDataList</apiname></xref> object and information
about the duration (for example, 12 seconds) in which rights are expected </p> <codeblock id="GUID-A371B670-1E6D-5513-8D5D-D6559170ED1F" xml:space="preserve">// Create meta-data array 
CMetaDataArray *metaDataArray = new (ELeave) CMetaDataArray(); 
CleanupStack::PushL(metaDataArray);

// Add any useful information we can think of.... 
metaDataArray-&gt;AddL(_L("Content Type"),_L("application/vnd.oma.drm.dm")); 
metaDataArray-&gt;AddL(_L("X-Oma-Drm-Separate-Delivery"),_L("12"));</codeblock> </section>
<section id="GUID-4023F3AD-6CA3-59E3-8148-F9D76480A05E"><title>Import a file</title> <ol id="GUID-8FC14D51-FB3B-5FC2-A24D-72AB9244CC93">
<li id="GUID-D1491E70-F9DF-5697-810A-9C91EFF5FF21"><p>Create the <codeph>CImportFile</codeph> object </p> </li>
<li id="GUID-F178800B-A2D5-50BC-B2D7-C363FBDDF43E"><p>Generate output files </p> </li>
</ol> <p><b>Creating the CImportFile object</b> </p> <p> <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CImportFile()</apiname></xref> allows
to write a file to CAF. Use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CSupplier::ImportFileL()</apiname></xref> to
create a <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile</apiname></xref> object
for importing a file. The parameters supplied must indicate whether the agent
generates the output files or if the application generates the output files
for the agents on demand. </p> <codeblock id="GUID-D5A84DF4-6175-5F56-97EE-2EDEA2E772B9" xml:space="preserve">// Create the import object, passing in the metaDataArray created earlier 
// The application must supply the output files 
            
CImportFile *import = mySupplier-&gt;ImportFileL(sourceMimeType, *metaDataArray);</codeblock> <p>Applications
use the <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile</apiname></xref> object
to transfer the content to CAF. </p> <p> <b>Note</b>: </p> <ul>
<li id="GUID-8B63B854-B857-5AC9-90BC-4A777B31A1E5"><p>You must create new <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile</apiname></xref> objects to import multiple
files. </p> </li>
<li id="GUID-FC33D732-6026-56DC-9047-A25188E4384A"><p>You can transfer only
one file in an instance, even if multiple output files are produced. </p> </li>
</ul> <p><b>Generating output files</b> </p> <p>Use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CSupplier::ImportFileL()</apiname></xref> to
generate the output files and specify the appropriate parameters. By default,
application generates the output file. Otherwise, the agent or application
can generate the output file based on the specified parameters. </p> <p><i>Agents
generating output files</i> </p> <p>Applications must specify the following
information if they require agents to generate the output files: </p> <ul>
<li id="GUID-E5B68249-133C-5C82-97AA-D47EFD73D984"><p>Specify the file name
in <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CSupplier::ImportFileL()</apiname></xref> indicating
that agent must generate output files. </p> </li>
<li id="GUID-3AEBE53D-B67F-58EA-A51E-E608851EA15B"><p>Use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CSupplier::SetOutputDirectoryL()</apiname></xref> to
specify the directory for the files to be generated. Optionally, applications
can decide to store the output files in their private directory. </p> </li>
<li id="GUID-9A4FA11A-CA72-5D46-89DE-8D086F788892"><p>Check for the number
of generated output files and their stored location, when the import operation
is complete. </p> </li>
</ul> <p><i>Applications generating output files</i></p> <p>If the filename
is not passed to the agent, applications provide output files to the agents.
This allows applications to open files in their own private directory and
ask the CAF agent to store the output in those files. This involves the following
considerations: </p> <ul>
<li id="GUID-F48701C5-8FAA-5B36-BF87-118B2D7D6784"><p>If an agent requires
a new output file handle in order to continue during import, a call to <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile::WriteData()</apiname></xref> or <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile::WriteDataComplete()</apiname></xref> returns
an error code of <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>KErrCANewFileHandleRequired</apiname></xref>. </p> </li>
<li id="GUID-CD957292-7438-53D2-9960-9648F07F017C"><p>Applications must open
a new output file with write access and call <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile::ContinueWithNewOutputFile()</apiname></xref> to
supply the new handle to the agent. IF handles are required further, <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile::ContinueWithNewOutputFile()</apiname></xref> returns <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>KErrCANewFileHandleRequired</apiname></xref> and the
application must repeat this step with another file. </p> <p>The agent must
cache its state before returning <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>KErrCANewFileHandleRequired</apiname></xref>. </p> </li>
<li id="GUID-CC0B5AF5-C1F0-5AFE-ACA9-5365CA3DAA45"><p>The application must
not resend the same <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile::WriteData()</apiname></xref> or <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>CImportFile::WriteDataComplete()</apiname></xref> call. </p> </li>
</ul><note> At the end of the import operation the output files are listed
irrespective of whether they were supplied by the application or the agent.</note> </section>
<section id="GUID-52D00B05-3EB5-5C10-A3BC-8AC12B968FF0"><title>Transfer the
file to the Content Access Agent</title><p>Use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CImportFile</apiname></xref> to
write the file data to CAF. <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CSupplier</apiname></xref> creates <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CImportFile</apiname></xref> which
only imports a single file. An application must call <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>WriteData()</apiname></xref> to
transfer a field in chunks to the CAF. </p> <p>The following code snippet
explains this. </p> <codeblock id="GUID-513744BC-F54A-55F5-A9BD-CA5463CB9DB1" xml:space="preserve">// importing the file data
ImportFile *import; 
TFileName fileName; 
TPath outputfileName; 
TBuf8 data &lt;128&gt; 
_LIT(KDirectoryPath, "C:\\private\\12345678\\");
... 

while(!endofsource) 
    {
    source.read(data); 
    err = import-&gt;WriteData(data); 

    // When application supplies file handles it must always check to see if 
    // the agent needs a new file handle 

    while(err == KErrCANewFileHandleRequired) 
        {               
        RFile newFile; 
        import-&gt;GetSuggestedOutputFileName(fileName); 
        outputFileName.Copy(KDirectoryPath); 
        outputFileName.Append(fileName);
        newFile.Open(outputFileName, EFileWrite); 
        err = import-&gt;ContinueWithNewOutputFile(newFile, outputFileName); 

        // It is possible that the agent needs yet another file handle
        newFile.Close(); // agent makes a copy so we don't need to keep our file handle 
        }
    }</codeblock> </section>
<section id="GUID-5436E5BC-793C-5373-B9A9-404D6ECC2EBA"><title>Complete the
import</title> <p>When the data is written, use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CImportFile::WriteDataComplete()</apiname></xref> to
inform the agent that data transfer is complete, allowing it to perform any
final processing. </p> <p>The following code snippet explains this step: </p> <codeblock id="GUID-1843B2F1-A862-52DB-998F-AE6224726EFB" xml:space="preserve">err = import-&gt;WriteDataComplete(); 

// When the application supplies file handles it must always check to see if 
// the agent needs a new file handle 
while(err == KErrCANewFileHandleRequired) 
    {
    RFile newFile; 
    import-&gt;GetSuggestedOutputFileName(fileName); 
    outputFileName.Copy(KDirectoryPath); 
    outputFileName.Append(fileName);  
    newFile.Open(outputFileName, EFileWrite);  
    err = import-&gt;ContinueWithNewOutputFile(newFile, outputFileName);
    // It is possible that the agent needs yet another file handle 
    newFile.Close(); // agent makes a copy so we don't need to keep our file handle
    }

// Finished
//At this stage all the agent's work is done and the CImportFile object can be deleted. </codeblock> </section>
<section id="GUID-EDAB286B-FBC9-5DAF-A466-7B07F2A2FC29"><title>Check the output
file</title> <p>When import is complete, use <xref href="GUID-E6562DDC-C872-3ADA-BF1C-4A04291E8CF9.dita"><apiname>ContentAccess::CImportFile::OutputFileL()</apiname></xref> to
list all the output files produced. The output files can be either content
files or receipts for DRM rights. </p> <codeblock id="GUID-A4C87E1E-719D-53CF-9A2F-7EEE8A16919D" xml:space="preserve">// loop over all the output files produced 
for(TInt I =0; I &lt; import-&gt;OutputFileCountL(); I++) 
    {
    // Can now retrieve filename, type of file (receipt or content) and MIME type for the file produced
    TPtr filename = import-&gt;OutputFileL(I).FileName(); 
    TOutputType type = import-&gt;OutputFileL(I).OutputType();
    TPtr8 mimetype = import-&gt;OutputFileL(I).MimeType(); 
    }</codeblock> <p> <b>Note</b>: </p> <p>The MIME type and the file extension
of the output files can be different to the MIME type and file extension of
the imported file. </p> </section>
</conbody><related-links>
<link href="GUID-84B6389A-55CC-53EB-8725-65F753FD7217.dita"><linktext> CAF Overview</linktext>
</link>
</related-links></concept>