NOTE: This is release marks a very large change to LucidJS, becoming fully prototypal, aswell as matching node's EventEmitter api. Don't worry, all of the functionallity of the 2.x.x releases can be found in this release aswell. The benifits of this release is that the emitter can now be inherited from, and you can use it in projects that currently use node's emitter by simply changing your require statement.
##Decouple components, make them lucid.
LucidJS is an event emitter library offering several unique features such as set events, emitter piping, sub events, along with the usual event triggering and binding. LucidJS emitters also feature meta events that allow listening for event binding and event triggering.
It works with AMD loaders, on NodeJS, and with the good old script tag.
###Set Events
LucidJS emitters have a method called .set()
.
Set allows you to bind to an event even after it
has happened.
var emitter = new lucidJS.EventEmitter();
emitter.flag('ready');
console.log('fired ready event');
setTimeout(function() {
emitter.bind('ready', function() {
console.log('listener bound and executed after ready event');
});
}, 2000);
>>> fired ready event
>>> listener bound and executed after ready event
Set is extremely useful for events that only happen
once and indicate state. Its the perfect solution
for load
, complete
or ready
events.
###Emitter Piping
Sometimes its nice to have a collection of emitters and a central emitter to aggregate them. This is possible with LucidJS emitters.
var centralEmitter = new lucidJS.EventEmitter();
var emitterA = new lucidJS.EventEmitter();
var emitterB = new lucidJS.EventEmitter();
var emitterC = new lucidJS.EventEmitter();
//pipe the foo event from emitter A
emitterA.pipe('foo', centralEmitter);
//pipe the bar and baz event from emitter B
emitterB.pipe(['bar', 'baz'], centralEmitter);
//pipe all events from emitter C
emitterC.pipe(centralEmitter);
###Sub Events
Ever wish you could have events with sub events?
LucidJS makes this possible. Trigger an event called
foo.bar.baz
will trigger foo.bar.baz
, foo.bar
,
and foo
.
var emitter = new lucidJS.EventEmitter();
emitter.bind('foo.bar', function() {
console.log('foo.bar');
});
emitter.bind('foo', function() {
console.log('foo');
});
emitter.emit('foo.bar.baz');
>>> 'foo.bar'
>>> 'foo'
###Simple Events
Along with all the tasty bits above LucidJS emitters are also very good at good old regular event passing.
var emitter = new lucidJS.EventEmitter();
emitter.bind('foo', function(arg1, arg2, arg3, arg4, arg5, arg6, arg7) {
console.log([arg1, arg2, arg3, arg4, arg5, arg6, arg7].join(' '));
});
emitter.emit('foo', 'any', 'number', 'of', 'arguments', 'can', 'be', 'passed');
>>> 'any number of arguments can be passed'
###Meta Events
LucidJS each emitter also emits a set of meta events that let you listen for new listeners on an emitter.
var emitter = new lucidJS.EventEmitter();
emitter.bind('emitter.listener', function(listener) {
console.log('captured listener', listener, 'on event ' + this.event);
});
emitter.bind('foo', function() { console.log('bar'); });
>>> 'captured listeners' function() { console.log('bar'); } 'on event foo'
You can event listen to all of the events emitted by an emitter.
var emitter = new lucidJS.EventEmitter();
emitter.bind('emitter.event', function(event) {
console.log('captured event ' + event);
});
emitter.emit('foo');
>>> 'captured event foo'
var eventEmitter = new lucidJS.EventEmitter();
EventEmitter is a drop in replacement for node's
event emitter. An event emitter can be created by
simply using the new
keyword.
To bind to an event you can use bind()
, or its
aliases addListener()
and addListener()
.
It accepts two arguments; An event, or array
of events, and a callback, or an array of
callbacks. Listeners are always triggered in the
order they are registered. The eventEmitter is
returned.
- eventEmitter.addListener
- eventEmitter.on
eventEmitter.bind(String event, Function listener([arg[, arg[, ...]])) => EventEmitter eventEmitter
eventEmitter.bind(Array events, Function listener([arg[, arg[, ...]])) => EventEmitter eventEmitter
eventEmitter.bind(String event, Array listeners) => EventEmitter eventEmitter
eventEmitter.bind(Array events, Array listeners) => EventEmitter eventEmitter
Argument Name | Allowed Types | Description |
---|---|---|
event | String | An event name to bind too. |
listener | String | A function to call when the event(s) are dispatched. |
events | Array | An array of event names to bind to. |
listeners | Array | An array of functions to call when the event(s) are dispatched. |
Similar to bind()
, weakBind()
binds a listener
to an event, however, weakBind()
automatically
unbinds its listener after its event is fired just
once. Listeners are always triggered in the order
they are registered. The eventEmitter is returned.
- eventEmitter.once
eventEmitter.weakBind(String event, Function listener([arg[, arg[, ...]])) => EventEmitter eventEmitter
eventEmitter.weakBind(Array events, Function listener([arg[, arg[, ...]])) => EventEmitter eventEmitter
eventEmitter.weakBind(String event, Array listeners) => EventEmitter eventEmitter
eventEmitter.weakBind(Array events, Array listeners) => EventEmitter eventEmitter
Argument Name | Allowed Types | Description |
---|---|---|
event | String | An event name to bind too. |
listener | String | A function to call when the event(s) are dispatched. |
events | Array | An array of event names to listen for. |
listeners | Array | An array of functions to call when the event(s) are dispatched. |
Unbinds a listener, or an array of listeners from an event, or events. Once a listener is unbound from an event, it will no longer fire when the event is dispatched. The eventEmitter is returned.
- eventEmitter.removeListener
- eventEmitter.off
eventEmitter.unbind(String event, Function listener([arg[, arg[, ...]])) => EventEmitter eventEmitter
eventEmitter.unbind(Array events, Function listener([arg[, arg[, ...]])) => EventEmitter eventEmitter
eventEmitter.unbind(String event, Array listeners) => EventEmitter eventEmitter
eventEmitter.unbind(Array events, Array listeners) => EventEmitter eventEmitter
Argument Name | Allowed Types | Description |
---|---|---|
event | String | An event the listener is bound to. |
listener | String | A listener to unbind from the event. |
events | Array | An array of events the listener is bound to. |
listeners | Array | An array of functions to unbind from the event. |
Dispatching events is done with emit()
, or its
alias trigger()
. Any listeners bound to the
event passed will be triggered immediately. Any
additional arguments are passed to the listeners.
Listeners are always triggered in the order they
are registered. The eventEmitter is returned.
- eventEmitter.trigger
eventEmitter.emit(String event, [* arg[, * arg[, ...]]]) => EventEmitter eventEmitter
eventEmitter.emit(Array events, [* arg[, * arg[, ...]]]) => EventEmitter eventEmitter
Argument Name | Allowed Types | Description |
---|---|---|
event | String | An event to trigger. |
events | Array | An array of events to trigger. |
arg | * | Any argument to be passed to all bound event listeners. |
Flags an event on an emitter. A setting a flag
will immediately trigger any event listeners bound
prior to calling flag
. Any listeners bound after
the flag is set will be triggered immediately
after they are bound. Any additional arguments are
passed to the listeners. The eventEmitter is
returned.
eventEmitter.flag(String event, [* arg[, * arg[, ...]]]) => EventEmitter eventEmitter
eventEmitter.flag(Array events, [* arg[, * arg[, ...]]]) => EventEmitter eventEmitter
Argument Name | Allowed Types | Description |
---|---|---|
event | String | An event the flag is bound to. |
events | Array | An array of events the flag is bound to. |
arg | * | Any argument to be passed to bound or future listeners. |
Argument Name | Allowed Types | Description |
---|
Argument Name | Allowed Types | Description |
---|
Argument Name | Allowed Types | Description |
---|
Argument Name | Allowed Types | Description |
---|
- eventEmitter.removeAllListeners
Argument Name | Allowed Types | Description |
---|
If you like my library feel free to use it however you want. If you wish to contribute to LucidJS please feel free to send me a pull request or make your own fork. Commentary is welcome on any of my projects.
Cheers and happy coding.