chapter.of: Extending the Store
created: 20140710184910226
modified: 20140717201408167
sub.num: 1
tags: doc new
title: Event Mechanism

Most of the following mechanisms need a way to get notified, when anything in the wiki store changes.
The core -plug-in adds an event system to the bare wiki store.
The event system provides the ability to listen to events. The most important is the "change" event which notifies the listeners when tiddlers have changed, with a list of the changed tiddlers.
The event mechanism is one of the few mechanisms which needs a hook at the microkernel:
The microkernel contains an empty function "enqueueTiddlerEvent(event)" and calls this function when a tiddler is added or deleted.
The event mechanism from the core plug-in overwrites this function with it's own implementation.
The functions providing the event system are added via the [[wikimethod module type]].