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<concept id="GUID-F55EAA3A-5D30-5983-9053-7C3935D99802" xml:lang="en"><title>Feature

Registry Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>This document provides an overview of the Feature Registry. </p>

<section><title>Purpose</title> <p>The Feature Registry allows

users to query whether optional Symbian platform features (identified by 32-bit

unique identifiers), are supported on a device prior to using them, and to

request notification of run-time feature changes. </p> </section>

<section><title>Architectural relationships</title> <p>The main input to the

Feature Registry is a configuration file, which is created by the <xref href="GUID-003D2C5B-09DC-5BD1-AF45-A0FCB56F567B.dita">ROMBUILD</xref> tool.

This file defines a set of feature flags, which can be accessed using the

Feature Registry API. </p> <p>The configuration file generated by the <codeph>ROMBUILD</codeph> tool

can be used to produce emulators specific to a particular ROM image using

the <codeph>EMULATORBUILD</codeph> tool. For more information, refer to the <xref href="GUID-6E4EFD1E-9215-55D9-A9B8-C5B9C554A71F.dita">OS Customisation</xref> guide. </p> </section>

<section><title>Description</title> <p>The main purpose of the Feature Registry

is to provide a public API for querying whether managed Symbian platform features

are supported on a device. </p> <p>Feature information is sourced from a configuration

file, which lists the status of features on the device. This configuration

file is created by the <xref href="GUID-003D2C5B-09DC-5BD1-AF45-A0FCB56F567B.dita">ROMBUILD</xref> tool. </p> <p>A

notification API is also provided for future enhancements in which the Feature

Registry is able to be updated during run-time. </p> <p><b>Features</b> </p> <p>A <i>feature</i> is a section of the Symbian platform API and its underlying

implementation, which accomplishes one or more useful tasks. Not all features

are supported on all Symbian platform devices. Some will be absent (unsupported)

because they are designated as optional features (sometimes referred to as

managed features) and device manufacturers have chosen not to include them

on a device. Others will be unavailable because they were added as part of

a later OS release or are UI-specific. </p> <p><b>Feature Management</b> </p> <p> <i>Feature Management</i> is the overall

process, which controls how parts of Symbian platform are designated as <i>features</i>,

given unique identifiers and tracked for inclusion or exclusion during the

ROM-build process. The Feature Registry is an Application Programming Interface

(API) to the Feature Management process, permitting applications to find out

what features are available on the device at run-time. It is used by developers

to find out whether optional features are supported on the device, prior to

using them. </p> </section>

</conbody><related-links>

<link href="GUID-F55EAA3A-5D30-5983-9053-7C3935D99802.dita"><linktext> Feature

Registry Overview </linktext></link>

<link href="GUID-B01EDE29-0861-52B0-97BE-8B41E580817F.dita"><linktext> Identifying

Optional                 Features</linktext></link>

<link href="GUID-747869DD-ECD1-5515-B876-0D7D753B1CD9.dita"><linktext> Optional

Features Query                 API </linktext></link>

<link href="GUID-9F9D6764-D86E-5665-B51A-04A4D3949FB4.dita"><linktext> Optional

Features                 Notification API </linktext></link>

</related-links></concept>