Event Emitter

Examples

var eventEmitter = new hx.EventEmitter;

eventEmitter.on('my-event', function(d){ console.log(d) });

// this will result in the object {x: 0, y: 123} being logged to the console
eventEmitter.emit('my-event', {
  x: 0,
  y: 123
});

Api

Change Log

Prototypes

hx.EventEmitter

A class that can be extended or used standalone to provide a way of emitting events to named registered callbacks. This is generally used internally to give objects the .on method for listening for events, but can be used as a standalone object if desired.

Constructors

hx.EventEmitter

Creates a new EventEmitter instance.

Methods

emitnameStringdataObjectEventEmitter

Emits an event to all listeners registered under the name supplied.

Arguments

nameString

The event type to emit.

data

Any data that should be sent along with the event

Returns

EventEmitter

This event emitter

hasnameStringBoolean

Checks if there are any callbacks registered for an event type.

Arguments

nameString

The event type to check.

Returns

Boolean

True if the event type has some callbacks registered.

offnameStringnamespaceStringcallbackFunctionEventEmitter

De-register a callback that was registered under the given name. If called with no arguments, all handlers will be removed from the event emitter for all names and namespaces.

Arguments

nameString

The event type this callback was registered under.

namespaceString

The namespace to remove handlers from. If not specified handlers will be removed from all namespaces. To remove handlers from the default handler supply "default" for the namespace name.

callback

The callback function to remove.

Returns

EventEmitter

This event emitter

onnameStringnamespaceStringcallbackFunctionEventEmitter

Arguments

nameString

The event type to listen out for

namespaceString

The namespace to register the handler under. Namespaces isolate groups of handlers. Handlers can be removed by namespace without affecting handlers in other namespaces. The value "default" is reserved and may not be used as a namespace name.

callbackdataEventData

The function to call when the event occurs

Arguments

dataEventData

The data sent along with the event

Returns

EventEmitter

This event emitter

pipeeventEmitterEventEmitterprefixStringfilterArray[String]EventEmitter

Pipes events from this event emitter into another. This makes it possible to chain multiple event emitters together if wanted.

Arguments

eventEmitterEventEmitter

The event emitter to send events to.

prefixString

A string to append to the names of events that get piped through

var ee1 = new hx.EventEmitter;
var ee2 = new hx.EventEmitter;

// pipe events from ee1 into ee2 with prefix `my-prefix`
ee1.pipe(ee2, 'my-prefix');

// listen for events from ee1 being piped through
ee2.on('my-prefix.click', function(){
  console.log('got here');
});

// will cause 'got here' to be logged
ee1.emit('click');

filterArray[String]

An array of event names to pipe through

var ee1 = new hx.EventEmitter;
var ee2 = new hx.EventEmitter;

// only pipe the 'click' and 'move' events from ee1 into ee2. ignore the rest
ee1.pipe(ee2, undefined, ['click', 'move']);

Returns

EventEmitter

This event emitter

suppressednameStringsuppressedBooleanEventEmitter

Sets whether events of a particular name should be suppressed (not emitted).

Arguments

nameString

The event name to change the suppression state of.

suppressedBoolean

True to prevent any events of the given name from being emitted, false to re-enable emission (which is the default behaviour).

Returns

EventEmitter