Class YAHOO.ext.util.Observable

Package:	YAHOO.ext.util
Class:	Observable
Extends:	Object
Subclasses:	BasicDialog, Button, ContentPanel, LayoutManager, LayoutRegion, Resizable, SplitBar, TabPanel, TabPanelItem, UpdateManager, View, AbstractColumnModel, AbstractDataModel, DefaultSelectionModel, Grid
Defined In:	yutil.js

Abstract base class that provides a common interface for publishing events. Subclasses are expected to to have a property "events" with all the events defined.
For example:

var Employee = function(name){
    this.name = name;
    this.events = {
        'fired' : new YAHOO.util.CustomEvent('fired'),
        'quit' : true // lazy initialize the CustomEvent
    }
 }
 YAHOO.extend(Employee, YAHOO.ext.util.Observable);

Public Properties

This class has no public properties.

Public Methods

Method		Defined By
	addListener(`String eventName`, `Function handler`, [`Object scope`], [`boolean override`]) : void	Observable
	Appends an event handler to this component	Observable
	bufferedListener(`String eventName`, `Function handler`, [`Object scope`], [`Number millis`]) : Function	Observable
	Appends an event handler to this component that is buffered. If the event is triggered more than once in the specifie...	Observable
	delayedListener(`String eventName`, `Function handler`, [`Object scope`], [`Number delay`]) : Function	Observable
	Appends an event handler to this component that is delayed the specified number of milliseconds. This is useful for e...	Observable
	fireEvent(`String eventName`, `Object... args`) : Boolean	Observable
	Fires the specified event with the passed parameters (minus the event name).	Observable
	on(`String eventName`, `Function handler`, [`Object scope`], [`boolean override`]) : void	Observable
	Appends an event handler to this element (shorthand for addListener)	Observable
	purgeListeners() : void	Observable
	Removes all listeners for this object	Observable
	removeListener(`String eventName`, `Function handler`, [`Object scope`]) : void	Observable
	Removes a listener	Observable

Public Events

This class has no public events.

Method Details

addListener

public function addListener(String eventName, Function handler, [Object scope], [boolean override])

Appends an event handler to this component

Parameters:

eventName : String
The type of event to listen for
handler : Function
The method the event invokes
scope : Object
(optional) The scope (this object) for the handler
override : boolean
(optional) If true, scope becomes the scope

Returns:

void

This method is defined by Observable.

bufferedListener

public function bufferedListener(String eventName, Function handler, [Object scope], [Number millis])

Appends an event handler to this component that is buffered. If the event is triggered more than once in the specified time-frame, only the last one actually fires.

Parameters:

eventName : String
The type of event to listen for
handler : Function
The method the event invokes
scope : Object
(optional) The scope (this object) for the handler
millis : Number
(optional) The number of milliseconds to buffer (defaults to 250)

Returns:

Function
The wrapped function that was created (can be used to remove the listener)

This method is defined by Observable.

delayedListener

public function delayedListener(String eventName, Function handler, [Object scope], [Number delay])

Appends an event handler to this component that is delayed the specified number of milliseconds. This is useful for events that modify the DOM and need to wait for the browser to catch up.

Parameters:

eventName : String
The type of event to listen for
handler : Function
The method the event invokes
scope : Object
(optional) The scope (this object) for the handler
delay : Number
(optional) The number of milliseconds to delay (defaults to 1 millisecond)

Returns:

Function
The wrapped function that was created (can be used to remove the listener)

This method is defined by Observable.

fireEvent

public function fireEvent(String eventName, Object... args)

Fires the specified event with the passed parameters (minus the event name).

Parameters:

eventName : String
args : Object...
Variable number of parameters are passed to handlers

Returns:

Boolean
returns false if any of the handlers return false otherwise it returns true

This method is defined by Observable.

on

public function on(String eventName, Function handler, [Object scope], [boolean override])

Appends an event handler to this element (shorthand for addListener)

Parameters:

eventName : String
The type of event to listen for
handler : Function
The method the event invokes
scope : Object
(optional) The scope (this object) for the handler
override : boolean
(optional) If true, scope becomes the scope

Returns:

void

This method is defined by Observable.

purgeListeners

public function purgeListeners()

Removes all listeners for this object

Parameters:

None.

Returns:

void

This method is defined by Observable.

removeListener

public function removeListener(String eventName, Function handler, [Object scope])

Removes a listener

Parameters:

eventName : String
The type of event to listen for
handler : Function
The handler to remove
scope : Object
(optional) The scope (this object) for the handler

Returns:

void

This method is defined by Observable.