Clear Up
SharpKit Reference

Observable Interface

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:

  
    Ext.define('Employee', {
            mixins: {
            observable: 'Ext.util.Observable'
            },
            constructor: function (config) {
            // The Observable constructor copies all of the properties of `config` on
            // to `this` using Ext.apply. Further, the `listeners` property is
            // processed to add listeners.
            //
            this.mixins.observable.constructor.call(this, config);
            this.addEvents(
            'fired',
            'quit'
            );
            }
            });
            

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!");
            }
            }
            });
            

Namespace: Ext.util

Derived Types

Methods

Name Description
addEvents(object) Adds the specified events to the list of events which this Observable may fire.
addListener(object, Delegate, object, object) Appends an event handler to this object. For example:
myGridPanel.on("mouseover", this.onMouseOver, this);
            
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
            });
            
One can also specify options for each event handler separately:
myGridPanel.on({
            cellClick: {fn: this.onCellClick, scope: this, single: true},
            mouseover: {fn: panel.onMouseOver, scope: panel}
            });
            
Names of methods in a specified scope may also be used. Note that scope MUST be specified to use this option:
myGridPanel.on({
            cellClick: {fn: 'onCellClick', scope: this, single: true},
            mouseover: {fn: 'onMouseOver', scope: panel}
            });
            
addManagedListener(object, object, Delegate, object, object) Adds listeners to any Observable object (or Ext.Element) which are automatically removed when this Component is destroyed.
clearListeners() Removes all listeners for this object including the managed listeners
clearManagedListeners() Removes all managed listeners for this object.
continueFireEvent(JsString, object, object) Continue to fire event.
createRelayer(object, object) Creates an event handling function which refires the event from this object as the passed event name.
enableBubble(object) 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.Base, {
            //  Add functionality to Field's initComponent to enable the change event to bubble
            initComponent : Ext.Function.createSequence(Ext.form.field.Base.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');
            }
            }
            });
            
fireEvent(JsString, Object[]) Fires the specified event with the passed parameters (minus the event name, plus the options object passed to addListener). An event may be set to bubble up an Observable parent hierarchy (See Ext.Component.getBubbleTarget) by calling enableBubble.
getBubbleParent() Gets the bubbling parent for an Observable
hasListener(JsString) Checks to see if this object has any listeners for a specified event, or whether the event bubbles. The answer indicates whether the event needs firing or not.
mon(object, object, Delegate, object, object) Shorthand for addManagedListener. Adds listeners to any Observable object (or Ext.Element) which are automatically removed when this Component is destroyed.
mun(object, object, Delegate, object) Shorthand for removeManagedListener. Removes listeners that were added by the mon method.
on(object, Delegate, object, object) Shorthand for addListener. Appends an event handler to this object. For example:
myGridPanel.on("mouseover", this.onMouseOver, this);
            
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
            });
            
One can also specify options for each event handler separately:
myGridPanel.on({
            cellClick: {fn: this.onCellClick, scope: this, single: true},
            mouseover: {fn: panel.onMouseOver, scope: panel}
            });
            
Names of methods in a specified scope may also be used. Note that scope MUST be specified to use this option:
myGridPanel.on({
            cellClick: {fn: 'onCellClick', scope: this, single: true},
            mouseover: {fn: 'onMouseOver', scope: panel}
            });
            
prepareClass(Delegate) Prepares a given class for observable instances. This method is called when a class derives from this class or uses this class as a mixin.
relayEvents(object, JsArray<T>, object) Relays selected events from the specified Observable as if the events were fired by this. For example if you are extending Grid, you might decide to forward some events from store. So you can do this inside your initComponent:
this.relayEvents(this.getStore(), ['load']);
            
The grid instance will then have an observable 'load' event which will be passed the parameters of the store's load event and any function fired with the grid's load event would have access to the grid using the this keyword.
removeListener(JsString, Delegate, object) Removes an event handler.
removeManagedListener(object, object, Delegate, object) Removes listeners that were added by the mon method.
removeManagedListenerItem(bool, object) Remove a single managed listener item
resumeEvents() Resumes 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.
suspendEvents(bool) Suspends the firing of all events. (see resumeEvents)
un(JsString, Delegate, object) Shorthand for removeListener. Removes an event handler.

Properties

Name Description
className Defaults to: "Ext.Base"
configMap Defaults to: {}
eventsSuspended Initial suspended call count. Incremented when suspendEvents is called, decremented when resumeEvents is called. Defaults to: 0
hasListeners This object holds a key for any event that has a listener. The listener may be set directly on the instance, or on its class or a super class (via observe) or on the MVC EventBus. The values of this object are truthy (a non-zero number) and falsy (0 or undefined). They do not represent an exact count of listeners. The value for an event is truthy if the event must be fired and is falsy if there is no need to fire the event. The intended use of this property is to avoid the expense of fireEvent calls when there are no listeners. This can be particularly helpful when one would otherwise have to call fireEvent hundreds or thousands of times. It is used like this:
if (this.hasListeners.foo) {
           this.fireEvent('foo', this, arg1);
           }
            
initConfigList Defaults to: []
initConfigMap Defaults to: {}
isInstance Defaults to: true
isObservable true in this class to identify an object as an instantiated Observable, or subclass thereof. Defaults to: true
self Get the reference to the current class from which this object was instantiated. Unlike statics, this.self is scope-dependent and it's meant to be used for dynamic inheritance. See statics for a detailed comparison
  Ext.define('My.Cat', {
            statics: {
            speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
            },
            constructor: function() {
            alert(this.self.speciesName); // dependent on 'this'
            },
            clone: function() {
            return new this.self();
            }
            });
            Ext.define('My.SnowLeopard', {
            extend: 'My.Cat',
            statics: {
            speciesName: 'Snow Leopard'         // My.SnowLeopard.speciesName = 'Snow Leopard'
            }
            });
            var cat = new My.Cat();                     // alerts 'Cat'
            var snowLeopard = new My.SnowLeopard();     // alerts 'Snow Leopard'
            var clone = snowLeopard.clone();
            alert(Ext.getClassName(clone));             // alerts 'My.SnowLeopard'
            
© Copyright 2005-2011 SharpKit. All rights reserved.