CAF Recogniser Config Overview

Purpose

The CAF Recogniser Config component includes a configuration file for the CAF Recogniser. The CAF Recogniser is a plug-in for the Apparc recogniser framework. It indicates to Apparc which MIME types must be associated with CAF. The CAF Recogniser config file contains the list of MIME types for the recogniser.

Key concepts

Recogniser

A recogniser is an ECom plug-in located under \sys\bin\ and loaded by the Application Architecture (Apparc) server. It identifies the data type of a file or a stream and associates it with an application that can handle the data. A data type is known as a MIME type. For more information about MIME and recognisers, see MIME Recognition Framework.

The CAF recogniser (reccaf.dll) determines whether data in a file or stream can be handled by CAF.

Apparc

Apparc contains a plug-in recogniser framework which locates all installed applications and associates them with the correct document and MIME types. Each application is stored in its own directory under \system\apps\ along with its associated icon, language-dependent binary resource file and application information file (.AIF). The .AIF file describes the application's capabilities and its UIDs. For more information, see Apparc Overview.

Open Mobile Alliance (OMA) DRM

The OMA DRM is a specification for Digital Rights Management. The OMA 2.0 standards define formats for storing DRM protected content in archive files. For more information, see http://www.openmobilealliance.org/

Description

The CAF Recogniser Config is a component which contains a single configuration file (RecCafMimeTypes.txt) for use by the CAF Recogniser (reccaf.dll). The recogniser uses this file and returns only MIME types listed in the file, when CApaCafRecognizer::SupportedDataTypeL() is called.

CAF Recogniser

The CAF Recogniser determines whether a file is recognized by CAF and if so, retrieves the file and content MIME types. The mapping of these two MIME types returned by CAF to a single APPARC MIME type is based on the following rules:

For more information about determining the MIME type of files used in Symbian platform, see Apparc Recognizer for CAF.

Application Registration Files

Applications must update their registration resource files (for example AppName_reg.rss) to include the new CAF MIME types.

For example, an image viewer may have only included image/jpeg in the list of MIME types it could open. If the application is updated to use CAF, it must support image/jpeg and x-caf-image/jpeg to support both unprotected and protected content respectively.

Registration file that uses CAF

...
    datatype_list =     
    {           
    DATATYPE { priority= EDataTypePriorityHigh ; type="image/jpeg"; },         
    DATATYPE { priority= EDataTypePriorityHigh ; type="x-caf-image/jpeg"; },     
    }
...

Registration file that does not use CAF

...
    datatype_list =     
    {           
    DATATYPE { priority= EDataTypePriorityHigh ; type="image/jpeg"; },         
    }
...

For more information see, Application Registration Files.

Configuration file

The configuration file is stored as \private\10003a3f\RecCaf\RecCafMimeTypes.txt in the Apparc server. The default implementation looks like this:

text/plain
text/html
image/jpeg
application/java-archive

Device creators must do the following during ROM build time and also see Considerations for Device Creators using CAF.

• Customize the configuration file to include all MIME types supported by CAF.

• Ensure all supported MIME types are included in the file, when post-production agent plug-ins are added in the CAF recogniser.

  By default, CAF loads all agents in the ROM drive. If post-production agent plug-ins are to be included, configure a macro CAF_LOAD_POST_PRODUCTION_AGENTS at ROM build time. This enables CAF to load all agents visible to ECom. For more information, see Content Access Agent ECom Resource File.

Typical uses

CAF recogniser (reccaf.dll) for DRM-protected content uses this configuration file to get the list of supported content MIME types.