@xassist/xassist-eventdispatcher NPM

@xassist/xassist-eventdispatcher

This module creates a general EventDispatcher class The class can beused to add listneres, and fire events.

Installation

If you use NPM, you can install the module via npm install xassist-eventdispatcher. Otherwise, you can download the latest minified file. Be aware any dependencies are not installed by default; you should consider downloading them yourself. If you want, you can install the complete library from github xassist, this includes all dependencies you may need.

The module uses UMD and supports AMD, CommonJS and vanilla environments. Using vanilla: the xaglobal is exported:

<script>
xa.EventDispatcher()
</script>

API

EventDispatcher()

The base function is the constructor-function for the class EventDispatcher.

EventDispatcher()
new EventDispatcher()

new is not needed since the constructor checks for the use of the keyword. EventDispatcher() requires no parameters.

Result for EventDispatcher()

EventDispatcher() returns a new class instance of the Class EventDispatcher

EventDispatcher(a).constructor.name===EventDispatcher

EventDispatcher returns 6 method:

registerEvent(): the method to register the events, so listeners can get attached
hasEvent(): a method to check if an event is registered
on(): add a listener to an event
once(): add a listener to an event, which will be removed when the event is fired the first time
fire(): fires an event
off(): removes a specific listener from an event

EventDispatcher has 1 own attributes:

_eventObject:here all registered events and listeners are stored

EventDispatcher().registerEvent()

EventDispatcher().registerEvent() registers events so it can be triggered in the future

EventDispatcher().registerEvent(eventName [,defaultThis])

Parameters for EventDispatcher().registerEvent()

EventDispatcher().registerEvent() takes 2 parameters:

eventName String:a string with the name for the event itself
defaultThis any datatype,defaults to: this:the default execution-context for the listeners

Result for EventDispatcher().registerEvent()

registerEvent returns an error if the event was registered before.

EventDispatcher().hasEvent()

The method EventDispatcher().hasEvent() checks if an event was registered before.

EventDispatcher().hasEvent(eventName)

Parameters for EventDispatcher().hasEvent()

EventDispatcher().hasEvent() takes 1 parameters:

eventName String:a string with the name for the event itself

Result for EventDispatcher().hasEvent()

It returns a boolean indicating if the event was registered.

EventDispatcher().on()

The method EventDispatcher().on() adds a listener for a certain event.

EventDispatcher().on(eventName,callBack [, thisArg])

EventDispatcher().on() returns nothing.

Parameters for EventDispatcher().on()

EventDispatcher().on() takes 3 parameters:

eventName String:a string with the name for the event itself.
callBack Function:the function which needs to be executed when the event is trigered
thisArg any datatype,defaults to: defaultThis:an optional reference for thisArg, the callBack will be binded on trigger of the event (not before, so you could change the callBack if needed)

EventDispatcher().once()

The method EventDispatcher().once() adds a listener for a certain event.

EventDispatcher().once(eventName,callBack [, thisArg])

once() is exactly the same the same as on(), but the listener will only gets executed once, even when the event is trigerred multiple times. EventDispatcher().once() returns nothing.

Parameters for EventDispatcher().once()

EventDispatcher().once() takes 3 parameters:

eventName String:a string with the name for the event itself.
callBack Function:the function which needs to be executed when the event is trigered
thisArg any datatype,defaults to: defaultThis:an optional reference for thisArg, the callBack will be binded on trigger of the event (not before, so you could change the callBack if needed)

EventDispatcher().off()

The method EventDispatcher().off() removes a listener for a certain event.

EventDispatcher().off(eventName,callBack )

EventDispatcher().off() returns nothing.

Parameters for EventDispatcher().off()

EventDispatcher().off() takes 2 parameters:

eventName String:a string with the name for the event itself.
callBack Function:the listener which needs to be removed

EventDispatcher().fire()

The method EventDispatcher().fire() fires an event.

EventDispatcher().fire(eventName /*list of other arguments*/ )

EventDispatcher().fire() returns nothing.

Parameters for EventDispatcher().fire()

EventDispatcher().fire() takes 2 parameters:

eventName String:a string with the name for the event itself.
/list or arguments/ any datatype:all other arguments that will be passed to the listeners as arguments