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These archived docs are for Phaser 2.6.1 Phaser 3 docs can be found on newdocs.phaser.io.
Phaser CE docs can be found on the Phaser CE Documentation site.

Constructor

Phaser. Signal

new Signal()

Signals are what Phaser uses to handle events and event dispatching. You can listen for a Signal by binding a callback / function to it. This is done by using either Signal.add or Signal.addOnce.

For example you can listen for a touch or click event from the Input Manager by using its onDown Signal:

game.input.onDown.add(function() { ... });

Rather than inline your function, you can pass a reference:

game.input.onDown.add(clicked, this); function clicked () { ... }

In this case the second argument (this) is the context in which your function should be called.

Now every time the InputManager dispatches the onDown signal (or event), your function will be called.

Very often a Signal will send arguments to your function. This is specific to the Signal itself. If you're unsure then check the documentation, or failing that simply do:

Signal.add(function() { console.log(arguments); })

and it will log all of the arguments your function received from the Signal.

Sprites have lots of default signals you can listen to in their Events class, such as:

sprite.events.onKilled

Which is called automatically whenever the Sprite is killed. There are lots of other events, see the Events component for a list.

As well as listening to pre-defined Signals you can also create your own:

var mySignal = new Phaser.Signal();

This creates a new Signal. You can bind a callback to it:

mySignal.add(myCallback, this);

and then finally when ready you can dispatch the Signal:

mySignal.dispatch(your arguments);

And your callback will be invoked. See the dispatch method for more details.

Source code: core/Signal.js (Line 60)

Public Properties

active : boolean

Is the Signal active? Only active signals will broadcast dispatched events.

Setting this property during a dispatch will only affect the next dispatch. To stop the propagation of a signal from a listener use halt.

Default Value
  • true
Source code: core/Signal.js (Line 100)

memorize : boolean

Memorize the previously dispatched event?

If an event has been memorized it is automatically dispatched when a new listener is added with add or addOnce. Use forget to clear any currently memorized event.

Source code: core/Signal.js (Line 84)

Public Methods

add(listener, listenerContext, priority, args) → {Phaser.SignalBinding}

Add an event listener for this signal.

An event listener is a callback with a related context and priority.

You can optionally provide extra arguments which will be passed to the callback after any internal parameters.

For example: Phaser.Key.onDown when dispatched will send the Phaser.Key object that caused the signal as the first parameter. Any arguments you've specified after priority will be sent as well:

fireButton.onDown.add(shoot, this, 0, 'lazer', 100);

When onDown dispatches it will call the shoot callback passing it: Phaser.Key, 'lazer', 100.

Where the first parameter is the one that Key.onDown dispatches internally and 'lazer', and the value 100 were the custom arguments given in the call to 'add'.

Parameters
Name Type Argument Default Description
listener function

The function to call when this Signal is dispatched.
listenerContext object <optional>

The context under which the listener will be executed (i.e. the object that should represent the this variable).
priority number <optional>

The priority level of the event listener. Listeners with higher priority will be executed before listeners with lower priority. Listeners with same priority level will be executed at the same order as they were added (default = 0)
args any <optional>
<repeatable>
 (none)

Additional arguments to pass to the callback (listener) function. They will be appended after any arguments usually dispatched.
Returns
Phaser.SignalBinding -

An Object representing the binding between the Signal and listener.

Source code: core/Signal.js (Line 232)

addOnce(listener, listenerContext, priority, args) → {Phaser.SignalBinding}

Add a one-time listener - the listener is automatically removed after the first execution.

If there is as memorized event then it will be dispatched and the listener will be removed immediately.

Parameters
Name Type Argument Default Description
listener function

The function to call when this Signal is dispatched.
listenerContext object <optional>

The context under which the listener will be executed (i.e. the object that should represent the this variable).
priority number <optional>

The priority level of the event listener. Listeners with higher priority will be executed before listeners with lower priority. Listeners with same priority level will be executed at the same order as they were added (default = 0)
args any <optional>
<repeatable>
 (none)

Additional arguments to pass to the callback (listener) function. They will be appended after any arguments usually dispatched.
Returns
Phaser.SignalBinding -

An Object representing the binding between the Signal and listener.

Source code: core/Signal.js (Line 274)

dispatch(params)

Dispatch / broadcast the event to all listeners.

To create an instance-bound dispatch for this Signal, use boundDispatch.

Parameters
Name Type Argument Description
params any <optional>

Parameters that should be passed to each handler.
Source code: core/Signal.js (Line 395)

dispose()

Dispose the signal - no more events can be dispatched.

This removes all event listeners and clears references to external objects. Calling methods on a disposed objects results in undefined behavior.

Source code: core/Signal.js (Line 451)

forget()

Forget the currently memorized event, if any.

Source code: core/Signal.js (Line 437)

getNumListeners() → {integer}

Gets the total number of listeners attached to this Signal.

Returns
integer -

Number of listeners attached to the Signal.

Source code: core/Signal.js (Line 369)

halt()

Stop propagation of the event, blocking the dispatch to next listener on the queue.

This should be called only during event dispatch as calling it before/after dispatch won't affect another broadcast. See active to enable/disable the signal entirely.

Source code: core/Signal.js (Line 381)

has(listener, context) → {boolean}

Check if a specific listener is attached.

Parameters
Name Type Argument Description
listener function

Signal handler function.
context object <optional>

Context on which listener will be executed (object that should represent the this variable inside listener function).
Returns
boolean -

If Signal has the specified listener.

Source code: core/Signal.js (Line 218)

remove(listener, context) → {function}

Remove a single event listener.

Parameters
Name Type Argument Default Description
listener function

Handler function that should be removed.
context object <optional>
 null

Execution context (since you can add the same handler multiple times if executing in a different context).
Returns
function -

Listener handler function.

Source code: core/Signal.js (Line 305)

removeAll(context)

Remove all event listeners.

Parameters
Name Type Argument Default Description
context object <optional>
 null

If specified only listeners for the given context will be removed.
Source code: core/Signal.js (Line 329)

toString() → {string}

A string representation of the object.

Returns
string -

String representation of the object.

Source code: core/Signal.js (Line 471)