SIP.EventEmitter

SIP.EventEmitter provides an interface for managing event callbacks (via on() and off() methods), as well as triggering those events (via emit()).

Example

// A SIP.js user agent implements the SIP.EventEmitter interface
myUA = new SIP.UA();

myUA.on('invite', function foo(session) {
    session.accept();
});

// Incoming invites will trigger foo() to be called

myUA.off('invite');

// Incoming invites will not trigger foo() to be called

• Example
• Construction
• Instance Methods
  • on(event, callback)
  • once(event, callback)
  • off([event[, callback]])
  • setMaxListeners(listeners)

Construction

The EventEmitter constructor is intended for internal use only.

Instance Methods

on(event, callback)

Register a method to be called each time a particular event is emitted.

Parameters

Name	Type	Description
event	String	The event which must be emitted to trigger the callback
callback	Function	The callback to be called when the event is emitted
bindTarget	Object	(Removed in 0.7.0) Please bind your target explicitly with callback.bind(bindTarget)

Returns

Type	Description
SIP.EventEmitter	This event emitter

once(event, callback)

Register a method to be called the next time a particular event is emitted. The callback will only be called once, even if the event is emitted multiple times.

Parameters

Name	Type	Description
event	String	The event which must be emitted to trigger the callback
callback	Function	The callback to be called when the event is emitted
bindTarget	Object	(Removed in 0.7.0) Please bind your target explicitly with callback.bind(bindTarget)

Returns

Type	Description
SIP.EventEmitter	This event emitter

off([event[, callback]])

Removes callback listeners from a particular event. The specific behavior varies depending on the number of arguments provided:

• off(event, callback) will remove all listeners for that event and callback.
• off(event) will remove all listeners for that event
• off() will remove all listeners for all events on the emitter. Warning: Using off() in this fashion is likely to break things!

Parameters

Name	Type	Description
event	String	The event for which to remove listeners.
callback	Function	The callback to stop calling.
bindTarget	Object	(Removed in 0.7.0) If your callback was bound, you must pass the bound function into off.

Returns

Type	Description
SIP.EventEmitter	This event emitter

setMaxListeners(listeners)

Change the maximum number of listeners per event that are allowed to be registered on this EventEmitter. The initial default is SIP.EventEmitter.C.MAX_LISTENERS: 10.

Parameters

Name	Type	Description
listeners	Number	The new maximum number of listeners per event