Symbian
Symbian OS Library

SYMBIAN OS V9.3

[Index] [Spacer] [Previous] [Next]



Migrating to Publish and Subscribe

The functionality provided by System Agent has been replaced by Publish & Subscribe, which is now the recommended way of setting and retrieving global information and for requesting notification when such global values are published.

This section deals with some of the issues relating to the migration.

Clients wishing to emulate System Agent exactly to support their own clients who may have already migrated to Publish & Subscribe in an earlier release, and who may be using a property category UID of KUidSystemCategory, will need to have ReadDeviceData & WriteDeviceData capabilities assigned to their binaries and their clients binaries to be able to access these system properties

A client makes a request for notification of changes to property using RProperty::Subscribe() and cancels a notification request using RProperty::Cancel(). There are some important differences between the System Agent notification requests and RProperty notifications requests:

System Agent offers functionality to get and set an array of properties, but RProperty does not provide this functionality.

To speed up the getting and setting of a property's values use RProperty::Attach() and the instance based (non-static) Get() and Set() member functions.