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Difference between revisions of "Events"

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(Why do we need events?)
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==Why do we need events?==
 
==Why do we need events?==
They link the identifiers to the point where the code needs modifying and as such they are vital.
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Events allow extensions to execute code in many locations within core phpBB code, without modifying any of the code. That way extensions can add features, remove functionality or modify behaviour easily and while maintaing easy compatability and simple update procedures.
  
 
== Naming ==
 
== Naming ==

Revision as of 22:55, 18 March 2012

What are events?

Events are triggered in various places of the core phpBB code. Listeners in extensions can be subscribed to these events. They are able to execute code whenever the respective event has occured. For more information, see the wiki article for listeners.

Former names for events are "hook location" and "ledge".

Why do we need events?

Events allow extensions to execute code in many locations within core phpBB code, without modifying any of the code. That way extensions can add features, remove functionality or modify behaviour easily and while maintaing easy compatability and simple update procedures.

Naming

Name Explanation
Events Events are triggered in various places of the core phpBB code. Listeners in extensions can be subscribed to these events. They are able to execute code whenever the respective event has occured. For more information, see the wiki article for listeners.
Listeners Listeners are triggered by events. They can process incoming data and manipulate variables in the scope of the event. So they can change phpBB's behaviour, add new functionality or if used in the context of templates, modify the output. An alternative name for listeners are "hooks".
Subscriber A subscriber takes care of letting the dispatcher know about listeners and which events they want to listen to.
Dispatcher The event dispatcher takes care of passing control flow to the listeners when an event occurs that they have been subscribed to by a subscriber.