EventEmitter.addEventListener

This method add a new listener or promotes existing one.

Usage

emitter.addEventListener(event, listener, dependencies);

Synonyms

• on
• addListener

Arguments

Argument	Type	Required	Description
event	string	✓	The name of the event.
listener	function	✓	The listener function added for that event.
dependencies	array or array-like object of functions		List of dependencies for that listener.

Return

The this EventEmitter instance.

Exceptions

• Throws a TypeError when listener is not a function.
• Throws a TypeError when dependencies is array or array-like objects, but contain other than function.
• Throws a ReferenceError when dependencies contain the listener (e.g. attempt to make listener dependency of itself).

Remarks

If a dependency is not added for as a listener for the given event, it'll be added as long as there are dependent listeners for it.

If listener already added for the specified event, following operation might happen:

• If a listener is not a normal listener (e.g. added either as dependency or with once), it'll be promoted to normal listener.
• If a list of dependencies is specified, it'll merged with current dependencies.