Managing +Files

Introduction

Some agents may choose to store content +files inside their server private directories. In the file system the private +directories have the following format:

\private\<process +SID>\protectedfile.ext

If an agent want to publish the +existence of its private directory, it specify the name of the private directory +(the SecureID of the process) in the opaque_data section +of the agent's ECom resource file. See Content +Access Agent ECOM Resource File.

CAF maps the path to the agent +name, so that it is human-readable. For example:

\private\<agent_name>\protectedfile.ext

The +agents can advertise the existence of files to applications through their +implementation of the ContentAccess::CAgentManager::GetDir() function. +When an application opens a file stored in the private directory, CAF selects +the agent which handles that content based upon the name in the path. If the +file is not stored in a private directory, CAF checks each of the agents whether +they support the file. If no agent supports the file, it reads as plaintext +using F32Agent.

Required background

Before you start, you must +understand:

Content +Access Framework for DRM
Content +Object Attributes

Procedure

Create a manager object +using the CManager::NewL() function.
Perform one or more +of the following tasks as per your requirement:
- Copy a file
- Move or rename a file
- Delete a file
- Create a directory
- List the contents of +a directory
- Find the real MIME type +of the file
- Get the attributes of +the content object
- Remove a directory

Copy a file

ContentAccess::CManager::CopyFile() allows +a user to make a copy of the file. For example, the user may wish to make +a copy of the file onto removable media. When copying content managed by a +DRM agent, the agent only copies the content, it does not copy the rights. + // create a manager object +CManager *manager = CManager::NewL(); + +// Use the manager to copy a file +TInt result = manager->CopyFile(source, destination);

Move or rename a file

ContentAccess::CManager::RenameFile() allows +a user to move or rename a file. For example, the user may wish to move the +file to removable media. TInt result = manager->RenameFile(oldFilename, newFilename);

Delete a file

ContentAccess::CManager::DeleteFileL() allows +a client to delete a specified file managed by a DRM agent.

The agent +responsible for the content can display a dialog to confirm that the user +wants to delete the file. This is particularly important if the content still +has valid rights.

The agent implementation must decide whether to +delete the rights or only the content.

TFileName filename; + +// Use the manager to delete a file +// CAF asks the agent which actually owns the file to delete it. +TInt result = manager->DeleteFile(filename);

Create a directory

ContentAccess::CManager::MkDir() allows +a user to create a directory.

TInt result = manager->MkDir(fullpath);

If one or more of the sub-directories do not exist they are created too using +the ContentAccess::CManager::MkDirAll() function.

TInt result = manager->MkDirAll(fullpath);

List the contents of a directory

There are three +variations of the ContentAccess::CManager::GetDir() function. +They each allow a client to list the contents of an agent's private directory.

As +mentioned earlier, it is optional for agents to provide this information.

CDir *aDir; +TInt result = manager->GetDir (aName, aEntryAttMask, aEntrySortKey, aDir);

Find the real MIME type of the file

The CAF Apparc +recognizer provides a MIME type that is a combination of the file MIME type +and the content within the file. In some cases, such as forwarding DRM content +to another device, it is important to make sure the content is sent with the +correct MIME type.

Using the "" empty string UniqueId allows +an application to determine the MIME type of the file.

TBuf <256> mimeType; +TInt result = manager->GetStringAttribute(EMimeType, mimeType, TVirtualPathPtr(aURI,KNullDesC16()));

Get the attributes of the content object

The CManager API +allows applications to retrieve attributes or string attributes from a content +object as described in Content +Object Attributes.

Remove a directory

ContentAccess::CManager::RmDir() allows +a user to remove a directory.

TInt result = manager->RmDir(fullpath);