Ext.util.Observable
Subclasses
Files
Base class that provides a common interface for publishing events. Subclasses are expected to
to have a property "events" with all the events defined, and, optionally, a property "listeners"
with configured listeners defined.
For example:
Employee = Ext.extend(Ext.util.Observable, {
constructor: function(config){
this.name = config.name;
this.addEvents({
"fired" : true,
"quit" : true
});
// Copy configured listeners into *this* object so that the base class's
// constructor will add them.
this.listeners = config.listeners;
// Call our superclass constructor to complete construction process.
Employee.superclass.constructor.call(this, config)
}
});
This could then be used like this:
var newEmployee = new Employee({
name: employeeName,
listeners: {
quit: function() {
// By default, "this" will be the object that fired the event.
alert(this.name + " has quit!");
}
}
});
Available since: 1.1.0
Config options
(optional)
A config object containing one or more event handlers to be added to this object during initialization. This should be a valid listeners config object as specified in the addListener example for attaching multiple handlers at once.
DOM events from ExtJs Components
While some ExtJs Component classes export selected DOM events (e.g. "click", "mouseover" etc), this
is usually only done when extra value can be added. For example the DataView's
click event passing the node clicked on. To access DOM
events directly from a child element of a Component, we need to specify the element option to
identify the Component property to add a DOM listener to:
new Ext.Panel({
width: 400,
height: 200,
dockedItems: [{
xtype: 'toolbar'
}],
listeners: {
click: {
element: 'el', //bind to the underlying el property on the panel
fn: function(){ console.log('click el'); }
},
dblclick: {
element: 'body', //bind to the underlying body property on the panel
fn: function(){ console.log('dblclick body'); }
}
}
});
Available since: 1.1.0
Properties
Defaults to: /^(?:scope|delay|buffer|single|stopEvent|preventDefault|stopPropagation|normalized|args|delegate|element|vertical|horizontal)$/
Available since: 1.1.0
Methods
Instance Methods addEvents( o, Optional )Adds the specified events to the list of events which this Observable may fire. ...Adds the specified events to the list of events which this Observable may fire.
Available since: 1.1.0
Parameters
- o : Object|String
Either an object with event names as properties with a value of true
or the first event name string if multiple event names are being passed as separate parameters.
- Optional : string
. Event name if multiple event names are being passed as separate parameters.
Usage:
this.addEvents('storeloaded', 'storecleared');
addListener( eventName, handler, [scope], [options] )Appends an event handler to this object. ...Appends an event handler to this object.
Available since: 1.1.0
Parameters
- eventName : String
The name of the event to listen for. May also be an object who's property names are event names. See
- handler : Function
The method the event invokes.
- scope : Object (optional)
The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
- options : Object (optional)
An object containing handler configuration.
properties. This may contain any of the following properties:
- scope : ObjectThe scope (
this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
- delay : NumberThe number of milliseconds to delay the invocation of the handler after the event fires.
- single : BooleanTrue to add a handler to handle just the next firing of the event, and then remove itself.
- buffer : NumberCauses the handler to be scheduled to run in an Ext.util.DelayedTask delayed
by the specified number of milliseconds. If the event fires again within that time, the original
handler is not invoked, but the new handler is scheduled in its place.
- target : ObservableOnly call the handler if the event was fired on the target Observable, not
if the event was bubbled up from a child Observable.
- element : StringThis option is only valid for listeners bound to Components.
The name of a Component property which references an element to add a listener to.
This option is useful during Component construction to add DOM event listeners to elements of Components which
will exist only after the Component is rendered. For example, to add a click listener to a Panel's body:
new Ext.Panel({
title: 'The title',
listeners: {
click: this.handlePanelClick,
element: 'body'
}
});
When added in this way, the options available are the options applicable to Ext.Element.addListener
Combining Options
Using the options argument, it is possible to combine different types of listeners:
A delayed, one-time listener.
myPanel.on('hide', this.handleClick, this, {
single: true,
delay: 100
});
Attaching multiple handlers in 1 call
The method also allows for a single argument to be passed which is a config object containing properties
which specify multiple events. For example:
myGridPanel.on({
cellClick: this.onCellClick,
mouseover: this.onMouseOver,
mouseout: this.onMouseOut,
scope: this // Important. Ensure "this" is correct during handler execution
});
.
addManagedListener( item, ename, fn, scope, opt )Adds listeners to any Observable object (or Element) which are automatically removed when this Component
is destroyed. ...Adds listeners to any Observable object (or Element) which are automatically removed when this Component
is destroyed.
Available since: 1.1.0
Parameters
- item : Observable|Element
The item to which to add a listener/listeners.
- ename : Object|String
The event name, or an object containing event name properties.
- fn : Function
Optional. If the ename parameter was an event name, this
is the handler function.
- scope : Object
Optional. If the ename parameter was an event name, this
is the scope (this reference) in which the handler function is executed.
- opt : Object
Optional. If the ename parameter was an event name, this
is the addListener options.
Removes all listeners for this object including the managed listeners ...Removes all listeners for this object including the managed listeners
Available since: 1.1.0
Removes all managed listeners for this object. ...Removes all managed listeners for this object.
Available since: 1.1.0
enableBubble( events )Enables events fired by this Observable to bubble up an owner hierarchy by calling
this.getBubbleTarget() if present. ...Enables events fired by this Observable to bubble up an owner hierarchy by calling
this.getBubbleTarget() if present. There is no implementation in the Observable base class.
This is commonly used by Ext.Components to bubble events to owner Containers. See Ext.Component.getBubbleTarget. The default
implementation in Ext.Component returns the Component's immediate owner. But if a known target is required, this can be overridden to
access the required target more quickly.
Example:
Ext.override(Ext.form.Field, {
// Add functionality to Field's initComponent to enable the change event to bubble
initComponent : Ext.createSequence(Ext.form.Field.prototype.initComponent, function() {
this.enableBubble('change');
}),
// We know that we want Field's events to bubble directly to the FormPanel.
getBubbleTarget : function() {
if (!this.formPanel) {
this.formPanel = this.findParentByType('form');
}
return this.formPanel;
}
});
var myForm = new Ext.formPanel({
title: 'User Details',
items: [{
...
}],
listeners: {
change: function() {
// Title goes red if form has been modified.
myForm.header.setStyle('color', 'red');
}
}
});
Available since: 1.1.0
Parameters
- events : String/Array
The event name to bubble, or an Array of event names.
fireEvent( eventName, args ) : BooleanFires the specified event with the passed parameters (minus the event name). ...Fires the specified event with the passed parameters (minus the event name).
An event may be set to bubble up an Observable parent hierarchy (See Ext.Component.getBubbleTarget)
by calling enableBubble.
Available since: 1.1.0
Parameters
- eventName : String
The name of the event to fire.
- 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.
hasListener( eventName ) : BooleanChecks to see if this object has any listeners for a specified event ...Checks to see if this object has any listeners for a specified event
Available since: 1.1.0
Parameters
- eventName : String
The name of the event to check for
Returns
- Boolean
True if the event is being listened for, else false
on( eventName, handler, [scope], [options] )Appends an event handler to this object (shorthand for addListener.) ...Appends an event handler to this object (shorthand for addListener.)
Available since: 1.1.0
Parameters
- eventName : String
The type of event to listen for
- handler : Function
The method the event invokes
- scope : Object (optional)
The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
- options : Object (optional)
An object containing handler configuration.
relayEvents( o, events )Relays selected events from the specified Observable as if the events were fired by this. ...Relays selected events from the specified Observable as if the events were fired by this.
Available since: 1.1.0
Parameters
- o : Object
The Observable whose events this object is to relay.
- events : Array
Array of event names to relay.
removeListener( eventName, handler, [scope] )Removes an event handler. ...Removes an event handler.
Available since: 1.1.0
Parameters
- eventName : String
The type of event the handler was associated with.
- handler : Function
The handler to remove. This must be a reference to the function passed into the addListener call.
- scope : Object (optional)
The scope originally specified for the handler.
removeManagedListener( item, ename, fn, scope )Removes listeners that were added by the mon method. ...Removes listeners that were added by the mon method.
Available since: 1.1.0
Parameters
- item : Observable|Element
The item from which to remove a listener/listeners.
- ename : Object|String
The event name, or an object containing event name properties.
- fn : Function
Optional. If the ename parameter was an event name, this
is the handler function.
- scope : Object
Optional. If the ename parameter was an event name, this
is the scope (this reference) in which the handler function is executed.
resumeEvents( )Resume firing events. ...Resume firing events. (see suspendEvents)
If events were suspended using the queueSuspended parameter, then all
events fired during event suspension will be sent to any listeners now.
Available since: 1.1.0
suspendEvents( queueSuspended )Suspend the firing of all events. ...Suspend the firing of all events. (see resumeEvents)
Available since: 1.1.0
Parameters
- queueSuspended : Boolean
Pass as true to queue up suspended events to be fired
after the resumeEvents call instead of discarding all suspended events;
un( eventName, handler, [scope] )Removes an event handler (shorthand for removeListener.) ...Removes an event handler (shorthand for removeListener.)
Available since: 1.1.0
Parameters
- eventName : String
The type of event the handler was associated with.
- handler : Function
The handler to remove. This must be a reference to the function passed into the addListener call.
- scope : Object (optional)
The scope originally specified for the handler.
Adds the specified events to the list of events which this Observable may fire.
Available since: 1.1.0
Parameters
- o : Object|String
Either an object with event names as properties with a value of
trueor the first event name string if multiple event names are being passed as separate parameters. - Optional : string
. Event name if multiple event names are being passed as separate parameters. Usage:
this.addEvents('storeloaded', 'storecleared');
Appends an event handler to this object.
Available since: 1.1.0
Parameters
- eventName : String
The name of the event to listen for. May also be an object who's property names are event names. See
- handler : Function
The method the event invokes.
- scope : Object (optional)
The scope (
thisreference) in which the handler function is executed. If omitted, defaults to the object which fired the event. - options : Object (optional)
An object containing handler configuration. properties. This may contain any of the following properties:
- scope : ObjectThe scope (
thisreference) in which the handler function is executed. If omitted, defaults to the object which fired the event. - delay : NumberThe number of milliseconds to delay the invocation of the handler after the event fires.
- single : BooleanTrue to add a handler to handle just the next firing of the event, and then remove itself.
- buffer : NumberCauses the handler to be scheduled to run in an Ext.util.DelayedTask delayed by the specified number of milliseconds. If the event fires again within that time, the original handler is not invoked, but the new handler is scheduled in its place.
- target : ObservableOnly call the handler if the event was fired on the target Observable, not if the event was bubbled up from a child Observable.
- element : StringThis option is only valid for listeners bound to Components. The name of a Component property which references an element to add a listener to.
This option is useful during Component construction to add DOM event listeners to elements of Components which will exist only after the Component is rendered. For example, to add a click listener to a Panel's body:
new Ext.Panel({ title: 'The title', listeners: { click: this.handlePanelClick, element: 'body' } });When added in this way, the options available are the options applicable to Ext.Element.addListener
Combining Options
Using the options argument, it is possible to combine different types of listeners:
A delayed, one-time listener.myPanel.on('hide', this.handleClick, this, { single: true, delay: 100 });Attaching multiple handlers in 1 call
The method also allows for a single argument to be passed which is a config object containing properties which specify multiple events. For example:
.myGridPanel.on({ cellClick: this.onCellClick, mouseover: this.onMouseOver, mouseout: this.onMouseOut, scope: this // Important. Ensure "this" is correct during handler execution }); - scope : Object
Adds listeners to any Observable object (or Element) which are automatically removed when this Component is destroyed.
Available since: 1.1.0
Parameters
- item : Observable|Element
The item to which to add a listener/listeners.
- ename : Object|String
The event name, or an object containing event name properties.
- fn : Function
Optional. If the
enameparameter was an event name, this is the handler function. - scope : Object
Optional. If the
enameparameter was an event name, this is the scope (thisreference) in which the handler function is executed. - opt : Object
Optional. If the
enameparameter was an event name, this is the addListener options.
Removes all listeners for this object including the managed listeners
Available since: 1.1.0
Removes all managed listeners for this object.
Available since: 1.1.0
Enables events fired by this Observable to bubble up an owner hierarchy by calling
this.getBubbleTarget() if present. There is no implementation in the Observable base class.
This is commonly used by Ext.Components to bubble events to owner Containers. See Ext.Component.getBubbleTarget. The default implementation in Ext.Component returns the Component's immediate owner. But if a known target is required, this can be overridden to access the required target more quickly.
Example:
Ext.override(Ext.form.Field, {
// Add functionality to Field's initComponent to enable the change event to bubble
initComponent : Ext.createSequence(Ext.form.Field.prototype.initComponent, function() {
this.enableBubble('change');
}),
// We know that we want Field's events to bubble directly to the FormPanel.
getBubbleTarget : function() {
if (!this.formPanel) {
this.formPanel = this.findParentByType('form');
}
return this.formPanel;
}
});
var myForm = new Ext.formPanel({
title: 'User Details',
items: [{
...
}],
listeners: {
change: function() {
// Title goes red if form has been modified.
myForm.header.setStyle('color', 'red');
}
}
});
Available since: 1.1.0
Parameters
- events : String/Array
The event name to bubble, or an Array of event names.
Fires the specified event with the passed parameters (minus the event name).
An event may be set to bubble up an Observable parent hierarchy (See Ext.Component.getBubbleTarget) by calling enableBubble.
Available since: 1.1.0
Parameters
- eventName : String
The name of the event to fire.
- 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.
Checks to see if this object has any listeners for a specified event
Available since: 1.1.0
Parameters
- eventName : String
The name of the event to check for
Returns
- Boolean
True if the event is being listened for, else false
Appends an event handler to this object (shorthand for addListener.)
Available since: 1.1.0
Parameters
- eventName : String
The type of event to listen for
- handler : Function
The method the event invokes
- scope : Object (optional)
The scope (
thisreference) in which the handler function is executed. If omitted, defaults to the object which fired the event. - options : Object (optional)
An object containing handler configuration.
Relays selected events from the specified Observable as if the events were fired by this.
Available since: 1.1.0
Parameters
- o : Object
The Observable whose events this object is to relay.
- events : Array
Array of event names to relay.
Removes an event handler.
Available since: 1.1.0
Parameters
- eventName : String
The type of event the handler was associated with.
- handler : Function
The handler to remove. This must be a reference to the function passed into the addListener call.
- scope : Object (optional)
The scope originally specified for the handler.
Removes listeners that were added by the mon method.
Available since: 1.1.0
Parameters
- item : Observable|Element
The item from which to remove a listener/listeners.
- ename : Object|String
The event name, or an object containing event name properties.
- fn : Function
Optional. If the
enameparameter was an event name, this is the handler function. - scope : Object
Optional. If the
enameparameter was an event name, this is the scope (thisreference) in which the handler function is executed.
Resume firing events. (see suspendEvents) If events were suspended using the queueSuspended parameter, then all events fired during event suspension will be sent to any listeners now.
Available since: 1.1.0
Suspend the firing of all events. (see resumeEvents)
Available since: 1.1.0
Parameters
- queueSuspended : Boolean
Pass as true to queue up suspended events to be fired after the resumeEvents call instead of discarding all suspended events;
Removes an event handler (shorthand for removeListener.)
Available since: 1.1.0
Parameters
- eventName : String
The type of event the handler was associated with.
- handler : Function
The handler to remove. This must be a reference to the function passed into the addListener call.
- scope : Object (optional)
The scope originally specified for the handler.
Static Methods capture( o, fn, [scope] )staticStarts capture on the specified Observable. ...Starts capture on the specified Observable. All events will be passed
to the supplied function with the event name + standard signature of the event
before the event is fired. If the supplied function returns false,
the event will not fire.
Available since: 1.1.0
Parameters
- o : Observable
The Observable to capture events from.
- fn : Function
The function to call when an event is fired.
- scope : Object (optional)
The scope (this reference) in which the function is executed. Defaults to the Observable firing the event.
observe( c, listeners )staticSets observability on the passed class constructor. ...Sets observability on the passed class constructor.
This makes any event fired on any instance of the passed class also fire a single event through
the class allowing for central handling of events on many instances at once.
Usage:
Ext.util.Observable.observe(Ext.data.Connection);
Ext.data.Connection.on('beforerequest', function(con, options) {
console.log('Ajax request made to ' + options.url);
});
Available since: 1.1.0
Parameters
- c : Function
The class constructor to make observable.
- listeners : Object
An object containing a series of listeners to add. See addListener.
releaseCapture( o )staticRemoves all added captures from the Observable. ...Removes all added captures from the Observable.
Available since: 1.1.0
Parameters
- o : Observable
The Observable to release
Starts capture on the specified Observable. All events will be passed to the supplied function with the event name + standard signature of the event before the event is fired. If the supplied function returns false, the event will not fire.
Available since: 1.1.0
Parameters
- o : Observable
The Observable to capture events from.
- fn : Function
The function to call when an event is fired.
- scope : Object (optional)
The scope (
thisreference) in which the function is executed. Defaults to the Observable firing the event.
Sets observability on the passed class constructor.
This makes any event fired on any instance of the passed class also fire a single event through the class allowing for central handling of events on many instances at once.
Usage:
Ext.util.Observable.observe(Ext.data.Connection);
Ext.data.Connection.on('beforerequest', function(con, options) {
console.log('Ajax request made to ' + options.url);
});Available since: 1.1.0
Parameters
- c : Function
The class constructor to make observable.
- listeners : Object
An object containing a series of listeners to add. See addListener.
Removes all added captures from the Observable.
Available since: 1.1.0
Parameters
- o : Observable
The Observable to release