emoney

E$

A lightweight event emitter for clients and servers.

Overview

E$ can be used as a standalone constructor, or to extend prototypical objects.

var emoneyStandalone = E$({
  handleE$: function( e ) { ... }
});

var emoneyExtended = (function() {

  function E$ishConstructor() {
    E$.construct( this );
  }

  E$ishConstructor.prototype = E$.create({
    handleE$: function( e ) { ... }
  });

  return new E$ishConstructor();

}());

E$ provides a clean way to interface with object instances.

emoneyExtended
.$when( 'loading' , function( e , pct ) {
  console.log( 'loading... (' + pct + '%)' );
})
.$when( 'ready' , function( e ) {
  console.log( 'ready!' );
})
.$when( 'error' , function( e , err ) {
  console.error( err.stack );
});

E$ instances can communicate via the handleE$ method.

emoneyExtended.$watch( emoneyStandalone );

// when emoneyStandalone emits an event
emoneyStandalone.$emit( 'gnarly' , [ 'something' , { rad: true }]);

// emoneyExtended.handleE$ is executed with arguments:
// [ event , something , { rad: true }]

Methods

Static Methods

E$.create( prototype )

creates a new object that extends the E$ prototype.

E$ishConstructor.prototype = E$.create({
  method1: function() { ... },
  method2: function() { ... },
  handleE$: function( e ) { ... }
});

E$.construct( instance )

defines required properties for an E$ instance.

function E$ishConstructor() {
  E$.construct( this );
  // ...
}

E$.is( subject )

determines whether subject is E$-ish.

var emoney = E$({ gnarly: true });
var emoneyIsh = new E$ishConstructor();
var somethingElse = new SomethingElse();

emoney instanceof E$;     // true
E$.is( emoney );          // true

emoneyIsh instanceof E$;  // false
E$.is( emoneyIsh );       // true

E$.is( somethingElse );   // false

Public Methods

All public methods can be chained.

.$when( events , [ args ] , [ handler ])

adds an event listener.

Parameter	Type	Description	Required
events	String Array	The event(s) to be handled.	yes
args	Variant Array	The argument(s) to be bound to the event handler.	no
handler	Function E$	The event handler. If E$.is( handler ) == true, the event will be bound to instance.handleE$. If handler is falsy, the event will be bound to emoney.handleE$.	no

// basic use
emoney.$when( 'gnarly' , function( e ) { ... });

// bind an argument to multiple events
emoney.$when([ 'gnarly' , 'rad' ] , 'arg' , function( e , arg ) { ... });

// bind multiple arguments to the wildcard event
emoney.$when( '*' , [ 'arg1' , 'arg2' ] , function( e , arg1 , arg2 ) { ... });

.$once( events , [ args ] , [ handler ])

adds an event listener that is removed after the first time it is invoked.

Parameter	Type	Description	Required
events	String Array	The event(s) to be handled.	yes
args	Variant Array	The argument(s) to be bound to the event handler.	no
handler	Function E$	the event handler	no

// basic use
emoney.$once( 'gnarly' , function( e ) { ... });

// bind an argument to multiple events
emoney.$once([ 'gnarly' , 'rad' ] , 'arg' , function( e , arg ) { ... });

// bind multiple arguments to the wildcard event
emoney.$once( '*' , [ 'arg1' , 'arg2' ] , function( e , arg1 , arg2 ) { ... });

.$emit( events , [ args ] , [ callback ])

emits an event.

Parameter	Type	Description	Required
events	String Array	the event(s) to be emitted	yes
args	Variant Array	the argument(s) to be passed to the event handler	no
callback	Function	a function to be executed at the end of the event chain (see event behavior)	no

// basic use
emoney.$emit( 'gnarly' , function( e ) { ... });

// pass an argument to multiple event handlers
emoney.$emit([ 'gnarly' , 'rad' ] , 'arg' , function( e ) { ... });

// pass multiple arguments to an event handler
emoney.$emit( 'gnarly' , [ 'arg1' , 'arg2' ] , function( e ) { ... });

.$dispel( events , [ wildcard ] , [ handler ])

removes an event listener.

Parameter	Type	Description	Required
events	String Array null	The event(s) to be removed.	yes
wildcard	Boolean	A boolean value denoting whether handlers bound to the wildcard event should be removed.	no
handler	Function E$	the event handler	no

// remove any gnarly listeners bound to handlerFunc
emoney.$dispel( 'gnarly' , handlerFunc );

// remove all gnarly or rad listeners bound to any handler
emoney.$dispel([ 'gnarly' , 'rad' ]);

// remove all listeners bound to handlerFunc except wildcard listeners
emoney.$dispel( null , handlerFunc );

// remove all listeners bound to handlerFunc
emoney.$dispel( null , true , handlerFunc );

// remove all listeners
emoney.$dispel( null , true );

.$watch( emitters )

starts listening to an E$ instance. emitter events will be handled by listener.handleE$.

Parameter	Type	Description	Required
emitters	E$ Array	The target E$ instance(s).	yes

// watch a single emitter
listener.$watch( emitter1 );

// watch multiple emitters
listener.$watch([ emitter1 , emitter2 ]);

.$ignore( emitters )

stops listening to an E$ instance.

Parameter	Type	Description	Required
emitters	E$ Array	The target E$ instance(s).	yes

// ignore a single emitter
listener.$ignore( emitter1 );

// ignore multiple emitters
listener.$ignore([ emitter1 , emitter2 ]);

Events

Properties

Property	Type	Default	Description
target	Object	n/a	The event target.
type	String	n/a	The event type.
defaultPrevented	Boolean	false	A flag denoting whether default was prevented.
cancelBubble	Boolean	false	A flag denoting whether propagation was stopped.
timeStamp	Float	n/a	The time at which the event was first triggered.

Methods

.preventDefault()

prevents the $emit callback from being executed.

emoney
.$when( 'gnarly' , function( e ) {
  e.preventDefault();
  console.log( 'handler1' );
})
.$when( 'gnarly' , function( e ) {
  console.log( 'handler2' );
})
.$emit( 'gnarly' , function( e ) {
  console.log( 'callback' );
});

/*
**  > 'handler1'
**  > 'handler2'
*/

.stopPropagation()

stops execution of the event chain and executes the emit callback.

emoney
.$when( 'gnarly' , function( e ) {
  e.stopPropagation();
  console.log( 'handler1' );
})
.$when( 'gnarly' , function( e ) {
  console.log( 'handler2' );
})
.$emit( 'gnarly' , function( e ) {
  console.log( 'callback' );
});

/*
**  > 'handler1'
**  > 'callback'
*/

Behavior

Build & Test

Build configs can be found in Gruntfile.js

default

Builds dev and prod releases, then runs tests.

grunt

test

Builds dev release and then runs tests.

grunt test

debug

Builds dev release, runs tests, then watches source files for changes.

grunt debug