Diffusion Apple API  6.6.2
Unified Client Library for iOS, tvOS and OS X / macOS
 All Classes Files Functions Variables Enumerations Enumerator Properties Pages
Topic Selectors


A topic selector identifies one or more topics. Topic selectors are created from a pattern expression.


Topic selectors are either evaluated by the Diffusion server or the local client library depending on the method they are passed to.

There exist subtle differences between the regular expression engines used to evaluate topic selectors depending on the evaluation location:

For this reason, topic selector expressions intended to be evaluated by the server are supplied to the local API as NSString objects. They are not parsed or verified by the local client, being passed through to the server 'as is'.

Topic selectors intended to be evaluated by the local client are supplied as PTDiffusionTopicSelector instances. As such, they are parsed and verified for syntax correctness locally on initialisation.