The LocalStorageProxy uses the new HTML5 localStorage API to save Model data locally on
the client browser. HTML5 localStorage is a key-value store (e.g. cannot save complex objects like JSON), so
LocalStorageProxy automatically serializes and deserializes data when saving and retrieving it.
localStorage is extremely useful for saving user-specific information without needing to build server-side
infrastructure to support it. Let's imagine we're writing a Twitter search application and want to save the user's
searches locally so they can easily perform a saved search again later. We'd start by creating a Search model:
Ext.regModel('Search', {
fields: ['id', 'query'],
proxy: {
type: 'localstorage',
id : 'twitter-Searches'
}
});
Our Search model contains just two fields - id and query - plus a Proxy definition. The only configuration we
need to pass to the LocalStorage proxy is an id. This is important as it separates the Model data in this
Proxy from all others. The localStorage API puts all data into a single shared namespace, so by setting an id we
enable LocalStorageProxy to manage the saved Search data.
Saving our data into localStorage is easy and would usually be done with a Store:
//our Store automatically picks up the LocalStorageProxy defined on the Search model
var store = new Ext.data.Store({
model: "Search"
});
//loads any existing Search data from localStorage
store.load();
//now add some Searches
store.add({query: 'Sencha Touch'});
store.add({query: 'Ext JS'});
//finally, save our Search data to localStorage
store.sync();
The LocalStorageProxy automatically gives our new Searches an id when we call store.sync(). It encodes the Model
data and places it into localStorage. We can also save directly to localStorage, bypassing the Store altogether:
var search = Ext.ModelMgr.create({query: 'Sencha Animator'}, 'Search');
//uses the configured LocalStorageProxy to save the new Search to localStorage
search.save();
Limitations
If this proxy is used in a browser where local storage is not supported, the constructor will throw an error.
A local storage proxy requires a unique ID which is used as a key in which all record data are stored in the
local storage object.
It's important to supply this unique ID as it cannot be reliably determined otherwise. If no id is provided
but the attached store has a storeId, the storeId will be used. If neither option is presented the proxy will
throw an error.
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'
The unique ID used as the key in which all record data are stored in the local storage object
The unique ID used as the key in which all record data are stored in the local storage 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 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'); }
}
}
});
model : String/Ext.data.Model The name of the Model to tie to this Proxy. Can be either the string name of
the Model, or a reference to the Model c...
The name of the Model to tie to this Proxy. Can be either the string name of
the Model, or a reference to the Model constructor. Required.
Cached map of records already retrieved by this Proxy - ensures that the same instance is always retrieved
Cached map of records already retrieved by this Proxy - ensures that the same instance is always retrieved
(
String eventName, Function handler, [Object scope] ) : Void
Removes an event handler (shorthand for removeListener.)
Removes an event handler (shorthand for
removeListener.)
Parameters
Returns
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
Returns
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. 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 : 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
This 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.core.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
});
.
Returns
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
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
Returns
- Ext.data.Batch The newly created Ext.data.Batch object
capture(
Observable o, Function fn, [Object scope] ) : Void
Starts capture on the specified Observable. All events will be passed
to the supplied function with the event name + ...
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.
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.
Returns
Destroys all records stored in the proxy and removes all keys and values used to support the proxy from the storage o...
Destroys all records stored in the proxy and removes all keys and values used to support the proxy from the storage object
Removes all listeners for this object including the managed listeners
Removes all listeners for this object including the managed listeners
Removes all managed listeners for this object.
Removes all managed listeners for this object.
create(
Ext.data.Operation operation, Function callback, Object scope ) : Void
Performs the given create operation.
Performs the given create operation.
Parameters
Returns
createAlias(
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
destroy(
Ext.data.Operation operation, Function callback, Object scope ) : Void
Performs the given destroy operation.
Performs the given destroy operation.
Parameters
Returns
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.Function.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
Returns
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
Returns
- Boolean returns false if any of the handlers return false otherwise it returns true.
Returns the model attached to this Proxy
Returns the model attached to this Proxy
Returns the reader currently attached to this proxy instance
Returns the reader currently attached to this proxy instance
Returns the writer currently attached to this proxy instance
Returns the writer currently attached to this proxy instance
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
Returns
- Boolean True if the event is being listened for, else false
observe(
Function c, Object listeners ) : Void
Sets observability on the passed class constructor.
This makes any event fired on any instance of the passed class al...
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);
});
Parameters
Returns
read(
Ext.data.Operation operation, Function callback, Object scope ) : Void
Performs the given read operation.
Performs the given read operation.
Parameters
Returns
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
Returns
Removes all added captures from the Observable.
Removes
all added captures from the Observable.
Parameters
Returns
removeListener(
String eventName, Function handler, [Object scope] ) : Void
Removes an event handler.
Removes an event handler.
Parameters
Returns
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
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.
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
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
Returns
- Ext.data.Reader The attached Reader object
setRecord(
Ext.data.Model record, String id ) : Void
Saves the given record in the Proxy. Runs each field's encode function (if present) to encode the data
Saves the given record in the Proxy. Runs each field's encode function (if present) to encode the data
Parameters
Returns
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
Returns
- Ext.data.Writer The attached Writer object
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
update(
Ext.data.Operation operation, Function callback, Object scope ) : Void
Performs the given update operation.
Performs the given update operation.
Parameters
Returns