Feature +Manager Collection Overview

The Feature Manager collection is a set of classes used to manipulate feature +flags.

Purpose

A +feature is any piece of functionality which can be included in a phone at +ROM build time or excluded from it. An excluded feature is often written to +ROM at build time but excluded from the build by disabling it.

Architecture

The +feature management system uses the standard client server architecture. The +relationship between the components is :

+ Architecture of the feature management system + + +

Feature Manager Client is not supplied with all versions of Symbian +Platform. Feature Discovery, which is always supplied, provides a subset of +the functionality of Feature Manager Client and offers superior performance +under certain circumstances.

The data which the Feature Manager manages +is stored as a collection of XML files in the feature database. These files +define a set of feature flags which can be accessed using the Feature Manager +API. The file featureuid.xml is the master record of +all features in the database. You do not manipulate the feature database directly. +

The feature manager database is also accessed by the tool feat2hdr.pl which +is used at ROM build time to convert the data relating to each feature into +.iby and .h files used by the source code of the components which the features +refer to.

Description

The +Feature Manager provides the functionality to

query features and report +on them,
modify the status of +features, and
set up notification +of changes to features.

Components

Feature Manager Client +provides the complete functionality required for feature management.
Feature Manager Server +maintains the table containing the list of features available on the device.
Feature Discovery provides +the functionality to discover if a feature or feature set is available but +not to enable, disable or modify features.

Feature flags were formerly managed using the Feature Registry component, +which has now been deprecated. The old Feature Registry API calls continue +to be supported, but the old implementation has been scrapped in favour of +wrapper functions which call Feature Manager.

Using Feature Manager

Feature flags, which are +held in the feature database, track changes to the status of features. It +is important to know that modifications through Feature Manager do not modify +the features themselves, though feature flags may be used by other components +which actually modify features.

The Feature Manager provides the functionality +to:

report the availability +of feature flags,
enable and disable feature +flags,
modify the status of +feature flags and the data associated with them, and
set up notification +of changes to the status of feature flags.

The Feature +Manager Tutorial provides detailed instructions on how to perform these +tasks.