Observable
  Proxy

Class Ext.data.Proxy

Package:	Ext.data
Defined In:	Proxy.js
Class:	Proxy
Subclasses:	ClientProxy, ServerProxy
Extends:	Observable

Proxies are used by Stores to handle the loading and saving of Model data. Usually developers will not need to create or interact with proxies directly.

Types of Proxy

There are two main types of Proxy - Client and Server. The Client proxies save their data locally and include the following subclasses:

LocalStorageProxy - saves its data to localStorage if the browser supports it
SessionStorageProxy - saves its data to sessionStorage if the browsers supports it
MemoryProxy - holds data in memory only, any data is lost when the page is refreshed

The Server proxies save their data by sending requests to some remote server. These proxies include:

AjaxProxy - sends requests to a server on the same domain
ScriptTagProxy - uses JSON-P to send requests to a server on a different domain

Proxies operate on the principle that all operations performed are either Create, Read, Update or Delete. These four operations are mapped to the methods create, read, update and destroy respectively. Each Proxy subclass implements these functions.

The CRUD methods each expect an operation object as the sole argument. The Operation encapsulates information about the action the Store wishes to perform, the model instances that are to be modified, etc. See the Operation documentation for more details. Each CRUD method also accepts a callback function to be called asynchronously on completion.

Proxies also support batching of Operations via a batch object, invoked by the batch method.

Config Options

Config Options		Defined By
	batchOrder : String Comma-separated ordering 'create', 'update' and 'destroy' actions when batching. Override this to set a different ord... Comma-separated ordering 'create', 'update' and 'destroy' actions when batching. Override this to set a different order for the batched CRUD actions to be executed in. Defaults to 'create,update,destroy'	Proxy
	defaultReaderType : String The default registered reader type. Defaults to 'json'	Proxy
	defaultWriterType : String The default registered writer type. Defaults to 'json'	Proxy
	listeners : Object A config object containing one or more event handlers to be added to this object during initialization. This should ... 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 a child element of a Component, we need to specify this explicitly: `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'); } } } });`	Observable

Public Properties

This class has no public properties.

Public Methods

Method		Defined By
	Proxy( `Object config` ) Creates the Proxy Creates the Proxy Parameters: `config` : Object Optional config object Returns: void	Proxy
	addEvents( `Object\|String o`, `string Optional.` ) : void 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. 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');` Returns: void	Observable
	addListener( `String eventName`, `Function handler`, [`Object scope`], [`Object options`] ) : void Appends an event handler to this object. Appends an event handler to this object. Parameters: `eventName` : String The name of the 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. properties. This may contain any of the following properties: scope : Object The scope (`this` reference) in which the handler function is executed. If omitted, defaults to the object which fired the event. delay : Number The number of milliseconds to delay the invocation of the handler after the event fires. single : Boolean True to add a handler to handle just the next firing of the event, and then remove itself. buffer : Number Causes 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 : Observable Only call the handler if the event was fired on the target Observable, not if the event was bubbled up from a child Observable. element : String The element reference on the component to bind the event to. This is used to bind DOM events to underlying elements on Components. - This option is only valid for listeners bound to Components Combining Options Using the options argument, it is possible to combine different types of listeners: A delayed, one-time listener. `myPanel.on('hide', this.onClick, 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 handlers. Returns: void	Observable
	addManagedListener( `Observable\|Element item`, `Object\|String ename`, `Function fn`, `Object scope`, `Object opt` ) : void 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. 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. Returns: void	Observable
	batch( `Object operations`, `Object listeners` ) : Ext.data.Batch Performs a batch of Operations, in the order specified by batchOrder. Used internally by Ext.data.Store's sync method... Performs a batch of Operations, in the order specified by batchOrder. Used internally by Ext.data.Store's sync method. Example usage: `myProxy.batch({ create : [myModel1, myModel2], update : [myModel3], destroy: [myModel4, myModel5] });` Where the myModel* above are Model instances - in this case 1 and 2 are new instances and have not been saved before, 3 has been saved previously but needs to be updated, and 4 and 5 have already been saved but should now be destroyed. Parameters: `operations` : Object Object containing the Model instances to act upon, keyed by action name `listeners` : Object Optional listeners object passed straight through to the Batch - see Ext.data.Batch Returns: `Ext.data.Batch` The newly created Ext.data.Batch object	Proxy
	clearListeners() : void Removes all listeners for this object including the managed listeners Removes all listeners for this object including the managed listeners Parameters: None. Returns: void	Observable
	clearManagedListeners() : void Removes all managed listeners for this object. Removes all managed listeners for this object. Parameters: None. Returns: void	Observable
	create( `Ext.data.Operation operation`, `Function callback`, `Object scope` ) : void Performs the given create operation. Performs the given create operation. Parameters: `operation` : Ext.data.Operation The Operation to perform `callback` : Function Callback function to be called when the Operation has completed (whether successful or not) `scope` : Object Scope to execute the callback function in Returns: void	Proxy
	destroy( `Ext.data.Operation operation`, `Function callback`, `Object scope` ) : void Performs the given destroy operation. Performs the given destroy operation. Parameters: `operation` : Ext.data.Operation The Operation to perform `callback` : Function Callback function to be called when the Operation has completed (whether successful or not) `scope` : Object Scope to execute the callback function in Returns: void	Proxy
	enableBubble( `String/Array events` ) : void 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'); } } }); Parameters: `events` : String/Array The event name to bubble, or an Array of event names. Returns: void	Observable
	fireEvent( `String eventName`, `Object... args` ) : Boolean Fires the specified event with the passed parameters (minus the event name). An event may be set to bubble up an Obse... 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. 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.	Observable
	getModel() : Ext.data.Model Returns the model attached to this Proxy Returns the model attached to this Proxy Parameters: None. Returns: `Ext.data.Model` The model	Proxy
	getReader() : Ext.data.Reader Returns the reader currently attached to this proxy instance Returns the reader currently attached to this proxy instance Parameters: None. Returns: `Ext.data.Reader` The Reader instance	Proxy
	getWriter() : Ext.data.Writer Returns the writer currently attached to this proxy instance Returns the writer currently attached to this proxy instance Parameters: None. Returns: `Ext.data.Writer` The Writer instance	Proxy
	hasListener( `String eventName` ) : Boolean Checks 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 Parameters: `eventName` : String The name of the event to check for Returns: `Boolean` True if the event is being listened for, else false	Observable
	on( `String eventName`, `Function handler`, [`Object scope`], [`Object options`] ) : void Appends an event handler to this object (shorthand for addListener.) Appends an event handler to this object (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` 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. Returns: void	Observable
	read( `Ext.data.Operation operation`, `Function callback`, `Object scope` ) : void Performs the given read operation. Performs the given read operation. Parameters: `operation` : Ext.data.Operation The Operation to perform `callback` : Function Callback function to be called when the Operation has completed (whether successful or not) `scope` : Object Scope to execute the callback function in Returns: void	Proxy
	relayEvents( `Object o`, `Array events` ) : void 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`. Parameters: `o` : Object The Observable whose events this object is to relay. `events` : Array Array of event names to relay. Returns: void	Observable
	removeListener( `String eventName`, `Function handler`, [`Object scope`] ) : void Removes an event handler. Removes an event handler. 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. Returns: void	Observable
	removeManagedListener( `Observable\|Element item`, `Object\|String ename`, `Function fn`, `Object scope` ) : void Removes listeners that were added by the mon method. Removes listeners that were added by the mon method. 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. Returns: void	Observable
	resumeEvents() : void Resume firing events. (see suspendEvents) If events were suspended using the queueSuspended parameter, then all event... 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. Parameters: None. Returns: void	Observable
	setModel( `String\|Ext.data.Model model`, `Boolean setOnStore` ) : void Sets the model associated with this proxy. This will only usually be called by a Store Sets the model associated with this proxy. This will only usually be called by a Store Parameters: `model` : String\|Ext.data.Model The new model. Can be either the model name string, or a reference to the model's constructor `setOnStore` : Boolean Sets the new model on the associated Store, if one is present Returns: void	Proxy
	setReader( `String\|Object\|Ext.data.Reader reader` ) : Ext.data.Reader Sets the Proxy's Reader by string, config object or Reader instance Sets the Proxy's Reader by string, config object or Reader instance Parameters: `reader` : String\|Object\|Ext.data.Reader The new Reader, which can be either a type string, a configuration object or an Ext.data.Reader instance Returns: `Ext.data.Reader` The attached Reader object	Proxy
	setWriter( `String\|Object\|Ext.data.Writer writer` ) : Ext.data.Writer Sets the Proxy's Writer by string, config object or Writer instance Sets the Proxy's Writer by string, config object or Writer instance Parameters: `writer` : String\|Object\|Ext.data.Writer The new Writer, which can be either a type string, a configuration object or an Ext.data.Writer instance Returns: `Ext.data.Writer` The attached Writer object	Proxy
	suspendEvents( `Boolean queueSuspended` ) : void Suspend the firing of all events. (see resumeEvents) Suspend the firing of all events. (see resumeEvents) Parameters: `queueSuspended` : Boolean Pass as true to queue up suspended events to be fired after the resumeEvents call instead of discarding all suspended events; Returns: void	Observable
	un( `String eventName`, `Function handler`, [`Object scope`] ) : void Removes an event handler (shorthand for removeListener.) Removes an event handler (shorthand for removeListener.) 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. Returns: void	Observable
	update( `Ext.data.Operation operation`, `Function callback`, `Object scope` ) : void Performs the given update operation. Performs the given update operation. Parameters: `operation` : Ext.data.Operation The Operation to perform `callback` : Function Callback function to be called when the Operation has completed (whether successful or not) `scope` : Object Scope to execute the callback function in Returns: void	Proxy

Public Events

This class has no public events.