Emitter2

emitter2 is a Titanium port of the EventEmitter2 for node.js. Don't cross the native bridge if you don't have to create and call event emitters from javascript for better performance.

For a more detailed explanation there is a great blog post by David Bankier The Toll on the Kroll Bridge

Features

• Namespaces/Wildcards.
• Times To Listen (TTL), extends the once concept with many.
• Add and fire native events with a simple wrapper

Installation

Clone the github repo and move the module to your apps commonjs module directory

$ tipm install tipm/events2

Add the module to you tiapp.xml

<modules>
  <module version="0.1.0">tipm-emitter2</module>
</modules>

Setup

The Config takes a configuration object.

    var EventEmitter = require('tipm-emitter2');
    var events = new EventEmitter({
      wildcard: true, // should the event emitter use wildcards.
      delimiter: '::', // the delimiter used to segment namespaces, defaults to `.`.
      maxListeners: 20, // the max number of listeners that can be assigned to an event, defaults to 10.
    });

Add a listeners for Native Proxy event with the proxy Namespace

*Only Proxy EventListners are hooked to the native events right now.

*If you manually fire a proxy event listener it will fire your listener but not the native event

    // Inherit from EventEmitter2
    WrappedView.prototype.__proto__ = EventEmitter.prototype;
    WrappedView.prototype.constructor = WrappedView;

    //Create WrapperView Object
    function WrapperView(options) {
      this.proxy = Ti.UI.createView(options);
    }

    var view = new WrapperView({top:10, left:10, height:10, width:10});

    // Add Proxy EventListener
    view.on('proxy.click', function(e){
      //Do something...
    });

    // Fire Proxy EventListner
    view.emit('proxy.click', {/*optional data to pass*/});

Getting the actual event that fired.

    app.on('foo.*', function(value1, value2) {
      console.log(this.event, value1, value2);
    });

Fire an event N times and then remove it, an extension of the once concept.

    app.many('foo', 4, function() {
      console.log('hello');
    });

Pass in a namespaced event as an array rather than a delimited string.

    app.many(['foo', 'bar', 'bazz'], function() {
      console.log('hello');
    });

API

When an EventEmitter instance experiences an error, the typical action is to emit an error event. Error events are treated as a special case. If there is no listener for it, then the default action is to print a stack trace and exit the program.

All EventEmitters emit the event newListener when new listeners are added.

Namespaces with Wildcards To use namespaces/wildcards, pass the wildcard option into the EventEmitter constructor. When namespaces/wildcards are enabled, events can either be strings (foo.bar) separated by a delimiter or arrays (['foo', 'bar']). The delimiter is also configurable as a constructor option.

An event name passed to any event emitter method can contain a wild card (the * character). If the event name is a string, a wildcard may appear as foo.*. If the event name is an array, the wildcard may appear as ['foo', '*'].

If either of the above described events were passed to the on method, subsequent emits such as the following would be observed...

   emitter.emit(['foo.bazz']);
   emitter.emit(['foo', 'bar']);

emitter.on(event, listener)

Adds a listener to the end of the listeners array for the specified event.

    app.on('data', function(value1, value2, value3 /* accepts any number of expected values... */) {
      console.log('The event was raised!');
    });

    app.on('data', function(value) {
      console.log('The event was raised!');
    });

emitter.addListener(event, listener)

Adds a listener to the end of the listeners array for the specified event. Alias of EventEmitter.on

javascript app.addListener('data', function(value1, value2, value3 /* accepts any number of expected values... */) { console.log('The event was raised!'); });

javascript app.addListener('data', function(value) { console.log('The event was raised!'); });

emitter.onAny(listener)

Adds a listener that will be fired when any event is emitted.

    app.onAny(function(value) {
      console.log('All events trigger this.');
    });

emitter.offAny(listener)

Removes the listener that will be fired when any event is emitted.

    app.offAny(function(value) {
      console.log('The event was raised!');
    });

emitter.once(event, listener)

Adds a one time listener for the event. The listener is invoked only the first time the event is fired, after which it is removed.

    app.once('get', function (value) {
      console.log('Ah, we have our first value!');
    });

emitter.many(event, timesToListen, listener)

Adds a listener that will execute n times for the event before being removed. The listener is invoked only the first time the event is fired, after which it is removed.

    app.many('get', 4, function (value) {
      console.log('This event will be listened to exactly four times.');
    });

emitter.off(event, listener)

Remove a listener from the listener array for the specified event. Caution: changes array indices in the listener array behind the listener.

    var callback = function(value) {
      console.log('someone connected!');
    };
    app.on('get', callback);
    // ...
    app.removeListener('get', callback);

emitter.removeListener(event, listener)

Alias of EventEmitter.off Remove a listener from the listener array for the specified event. Caution: changes array indices in the listener array behind the listener.

    var callback = function(value) {
      console.log('someone connected!');
    };
    app.on('get', callback);
    // ...
    app.removeListener('get', callback);

emitter.removeAllListeners([event])

Removes all listeners, or those of the specified event.

emitter.setMaxListeners(n)

By default EventEmitters will print a warning if more than 10 listeners are added to it. This is a useful default which helps finding memory leaks. Obviously not all Emitters should be limited to 10. This function allows that to be increased. Set to zero for unlimited.

emitter.listeners(event)

Returns an array of listeners for the specified event. This array can be manipulated, e.g. to remove listeners.

    app.on('get', function(value) {
      console.log('someone connected!');
    });
    console.log(console.log(app.listeners('get')); // [ [Function] ]

emitter.listenersAny()

Returns an array of listeners that are listening for any event that is specified. This array can be manipulated, e.g. to remove listeners.

    app.onAny(function(value) {
      console.log('someone connected!');
    });
    console.log(console.log(app.listenersAny()[0]); // [ [Function] ] // someone connected!

emitter.emit(event, [arg1], [arg2], [...])

Execute each of the listeners that may be listening for the specified event name in order with the list of arguments.

License

(The MIT License)

Copyright (c) 2012 Christian Sullivan <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.