The following sections illustrate the most common use cases of OMA DRM CAF Agent API
// allocate a content object, specify that we only want to peek at it
CContent* content = CContent::NewL(fileName, EPeek, EContentShareReadOnly);
TInt value = 0;
if (content->GetAttribute(EFileType, value) == KErrNone)
{
if (value == ENoDcf)
{
// the file is not an OMA DRM file
}
else if (value == EOma1Dcf)
{
// the file is an OMA DRM 1.0 file
}
else if (value == EOma2Dcf)
{
// the file is an OMA DRM 2.0 file
}
}
else
{
// the file type could not be determined
}
// allocate a data object, specify that we only want to peek at it, and
// that we want the default part of the file
CData* data = CData::NewL(TVirtualPathPtr(fileName, KDefaultContentObject),
EPeek, EContentShareReadOnly);
TBuf<256> part;
if (data->GetStringAttribute(EInstantPreviewUri, part) == KErrNone &&
part.Length() > 0)
{
delete data;
// open the part, now with the actual intent
data = CData::NewL(TVirtualPathPtr(fileName, part), EView,
EContentShareReadOnly);
// do something with the data
…
}
else
{
// no preview part available
}
// allocate a content object, specify that we only want to peek at it,
// but we need to be able to write
CContent* content = CContent::NewL(fileName, EPeek, EContentShareReadWrite);
if (content->AgentSpecificCommand(EEmbedDomainRo, KNullDesC, KNullDesC) ==
KErrNone)
{
// embedding succeeded
}
// Import is handling via the CSupplier class
CSupplier* supplier = CSupplier::NewLC();
CMetaDataArray* metaData = CMetaDataArray::NewLC();
// Set the target for the encrypted file
supplier->SetOutputDirectoryL(KEncryptedDir);
// The agent is selected based on the MIME type of the data to be imported
CImportFile* file = supplier->ImportFileL(KOma1DrmMessageContentType,
*metaData, KTempDcfName);
file->WriteData(KDMSimple);
file->WriteDataComplete();
CSupplierOutputFile& output = file->OutputFileL(0);
CSupplier* supplier = CSupplier::NewLC();
CMetaDataArray* metaData = CMetaDataArray::NewLC();
// Tell the agent which MIME type to use for the encrypted data
metaData->AddL(KOmaImportMimeTypeField, _L8("image/gif"));
supplier->SetOutputDirectoryL(KEncryptedDir);
// The KOmaImportContentType is a OMA DRM agent specific MIME type which
// indicates that plain content is to be encrypted
CImportFile* file = supplier->ImportFileL(KOmaImportContentType,
*metaData, KTempDcfName);
file->WriteData(KDMSimple);
file->WriteDataComplete();
CSupplierOutputFile& output = file->OutputFileL(0);
Error handling is defined in relevant CAF operations. In addition to that,
the KErrOverflow error indicates that the given output buffer
is not large enough to hold the result of the requested operation.
The methods returning string attribute values and the agent specific commands
must be called with enough memory allocated in the output parameters. Otherwise,
the function calls fail with the KErrOverflow error code.
CAF API can be extended using agent-specific commands and attributes, and OMA DRM CAF Agent API is such an extension. It is expected that any additional functionality of OMA DRM CAF Agent will be provided by adding new attribute and command enumeration values.