Hierarchy
Ext.data.proxy.ProxyExt.data.proxy.ServerExt.data.proxy.JsonPMixins
JsonPProxy is useful when you need to load data from a domain other than the one your application is running on. If your application is running on http://domainA.com it cannot use Ajax to load its data from http://domainB.com because cross-domain ajax requests are prohibited by the browser.
We can get around this using a JsonPProxy. JsonPProxy injects a <script> tag into the DOM whenever an AJAX request would usually be made. Let's say we want to load data from http://domainB.com/users - the script tag that would be injected might look like this:
<script src="http://domainB.com/users?callback=someCallback"></script>
When we inject the tag above, the browser makes a request to that url and includes the response as if it was any other type of JavaScript include. By passing a callback in the url above, we're telling domainB's server that we want to be notified when the result comes in and that it should call our callback function with the data it sends back. So long as the server formats the response to look like this, everything will work:
someCallback({
users: [
{
id: 1,
name: "Ed Spencer",
email: "ed@sencha.com"
}
]
});
As soon as the script finishes loading, the 'someCallback' function that we passed in the url is called with the JSON object that the server returned.
JsonPProxy takes care of all of this automatically. It formats the url you pass, adding the callback parameter automatically. It even creates a temporary callback function, waits for it to be called and then puts the data into the Proxy making it look just like you loaded it through a normal AjaxProxy. Here's how we might set that up:
Ext.define('User', {
extend: 'Ext.data.Model',
fields: ['id', 'name', 'email']
});
var store = new Ext.data.Store({
model: 'User',
proxy: {
type: 'jsonp',
url : 'http://domainB.com/users'
}
});
store.load();
That's all we need to do - JsonPProxy takes care of the rest. In this case the Proxy will have injected a script tag like this:
<script src="http://domainB.com/users?callback=stcCallback001" id="stcScript001"></script>
Customization
Most parts of this script tag can be customized using the callbackParam, callbackPrefix and scriptIdPrefix configurations. For example:
var store = new Ext.data.Store({
model: 'User',
proxy: {
type: 'jsonp',
url : 'http://domainB.com/users',
callbackParam: 'theCallbackFunction',
callbackPrefix: 'ABC',
scriptIdPrefix: 'injectedScript'
}
});
store.load();
Would inject a script tag like this:
<script src="http://domainB.com/users?theCallbackFunction=ABC001" id="injectedScript001"></script>
Implementing on the server side
The remote server side needs to be configured to return data in this format. Here are suggestions for how you might achieve this using Java, PHP and ASP.net:
Java:
boolean jsonP = false;
String cb = request.getParameter("callback");
if (cb != null) {
jsonP = true;
response.setContentType("text/javascript");
} else {
response.setContentType("application/x-json");
}
Writer out = response.getWriter();
if (jsonP) {
out.write(cb + "(");
}
out.print(dataBlock.toJsonString());
if (jsonP) {
out.write(");");
}
PHP:
$callback = $_REQUEST['callback'];
// Create the output object.
$output = array('a' => 'Apple', 'b' => 'Banana');
//start output
if ($callback) {
header('Content-Type: text/javascript');
echo $callback . '(' . json_encode($output) . ');';
} else {
header('Content-Type: application/x-json');
echo json_encode($output);
}
ASP.net:
String jsonString = "{success: true}";
String cb = Request.Params.Get("callback");
String responseString = "";
if (!String.IsNullOrEmpty(cb)) {
responseString = cb + "(" + jsonString + ")";
} else {
responseString = jsonString;
}
Response.Write(responseString);
Specific urls to call on CRUD action methods "read", "create", "update" and "destroy". Defaults to:
api: {
read : undefined,
create : undefined,
update : undefined,
destroy : undefined
}
The url is built based upon the action being executed [load|create|save|destroy] using the commensurate api property, or if undefined default to the configured Ext.data.Store.url.
For example:
api: {
load : '/controller/load',
create : '/controller/new',
save : '/controller/update',
destroy : '/controller/destroy_action'
}
If the specific URL for a given CRUD action is undefined, the CRUD action request will be directed to the configured url.
True to automatically append the request's params to the generated url. Defaults to true
True to automatically append the request's params to the generated url. Defaults to true
True to batch actions of a particular type when synchronizing the store. Defaults to true.
True to batch actions of a particular type when synchronizing the store. Defaults to true.
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 name of the cache param added to the url when using noCache (defaults to "_dc")
The name of the cache param added to the url when using noCache (defaults to "_dc")
(Optional) See Ext.data.JsonP.callbackKey.
(Optional) See Ext.data.JsonP.callbackKey.
The name of the direction parameter to send in a request. This is only used when simpleSortMode is set to true. Defaults to 'dir'.
Extra parameters that will be included on every request. Individual requests with params of the same name will override these params when they are in conflict.
The name of the 'filter' parameter to send in a request. Defaults to 'filter'. Set this to undefined if you don't want to send a filter parameter
The name of the 'group' parameter to send in a request. Defaults to 'group'. Set this to undefined if you don't want to send a group parameter
The name of the 'limit' parameter to send in a request. Defaults to 'limit'. Set this to undefined if you don't want to send a limit parameter
(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.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'); }
}
}
});
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.
(optional) Defaults to true. Disable caching by adding a unique parameter name to the request.
(optional) Defaults to true. Disable caching by adding a unique parameter name to the request.
The name of the 'page' parameter to send in a request. Defaults to 'page'. Set this to undefined if you don't want to send a page parameter
The Ext.data.reader.Reader to use to decode the server's response. This can either be a Reader instance, a config object or just a valid Reader type name (e.g. 'json', 'xml').
The param name to use when passing records to the server (e.g. 'records=someEncodedRecordString'). Defaults to 'records'
Enabling simpleSortMode in conjunction with remoteSort will only send one sort property and a direction when a remote sort is requested. The directionParam and sortParam will be sent with the property name and either 'ASC' or 'DESC'
The name of the 'sort' parameter to send in a request. Defaults to 'sort'. Set this to undefined if you don't want to send a sort parameter
The name of the 'start' parameter to send in a request. Defaults to 'start'. Set this to undefined if you don't want to send a start parameter
(optional) The number of milliseconds to wait for a response. Defaults to 30 seconds.
(optional) The number of milliseconds to wait for a response. Defaults to 30 seconds.
The Ext.data.writer.Writer to use to encode any request sent to the server. This can either be a Writer instance, a config object or just a valid Writer type name (e.g. 'json', 'xml').
Aborts the current server request if one is currently running
Aborts the current server request if one is currently running
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.
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.
[additional] Optional additional event names if multiple event names are being passed as separate parameters. Usage:
this.addEvents('storeloaded', 'storecleared');
Appends an event handler to this object.
Appends an event handler to this object.
The name of the event to listen for. May also be an object who's property names are event names. See
The method the event invokes.
(optional) The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
(optional) An object containing handler configuration. properties. This may contain any of the following properties:
this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.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.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
});
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.
The item to which to add a listener/listeners.
The event name, or an object containing event name properties.
Optional. If the ename parameter was an event name, this
is the handler function.
Optional. If the ename parameter was an event name, this
is the scope (this reference) in which the handler function is executed.
Optional. If the ename parameter was an event name, this
is the addListener options.
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.
Object containing the Model instances to act upon, keyed by action name
Optional listeners object passed straight through to the Batch - see Ext.data.Batch
The newly created Ext.data.Batch object
Creates and returns an Ext.data.Request object based on the options passed by the Store that this Proxy is attached to.
Creates and returns an Ext.data.Request object based on the options passed by the Store that this Proxy is attached to.
The Operation object to execute
The request object
Generates a url based on a given Ext.data.Request object. Adds the params and callback function name to the url
Generates a url based on a given Ext.data.Request object. Adds the params and callback function name to the url
The request object
The url
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.
The Observable to capture events from.
The function to call when an event is fired.
(optional) The scope (this reference) in which the function is executed. Defaults to the Observable firing the event.
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.
In ServerProxy subclasses, the create, read, update and destroy methods all pass through to doRequest. Each ServerProxy subclass must implement the doRequest method - see Ext.data.proxy.JsonP and Ext.data.proxy.Ajax for examples. This method carries the same signature as each of the methods that delegate to it.
The Ext.data.Operation object
The callback function to call when the Operation has completed
The scope in which to execute the callback
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');
}
}
});
The event name to bubble, or an Array of event names.
Encodes the array of Ext.util.Filter objects into a string to be sent in the request url. By default, this simply JSON-encodes the filter data
The array of Filter objects
The encoded filters
Encodes an array of records into a string suitable to be appended to the script src url. This is broken out into its own function so that it can be easily overridden.
The records array
The encoded records string
Encodes the array of Ext.util.Sorter objects into a string to be sent in the request url. By default, this simply JSON-encodes the sorter data
The array of Sorter objects
The encoded sorters
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.
The name of the event to fire.
Variable number of parameters are passed to handlers.
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
The model
Returns the reader currently attached to this proxy instance
Returns the reader currently attached to this proxy instance
The Reader instance
Returns the writer currently attached to this proxy instance
Returns the writer currently attached to this proxy instance
The Writer 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
The name of the event to check for
True if the event is being listened for, else false
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);
});
The class constructor to make observable.
An object containing a series of listeners to add. See addListener.
Appends an event handler to this object (shorthand for addListener.)
Appends an event handler to this object (shorthand for addListener.)
The type of event to listen for
The method the event invokes
(optional) The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
(optional) An object containing handler configuration.
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.
The Observable whose events this object is to relay.
Array of event names to relay.
Removes all added captures from the Observable.
Removes all added captures from the Observable.
The Observable to release
Removes an event handler.
Removes an event handler.
The type of event the handler was associated with.
The handler to remove. This must be a reference to the function passed into the addListener call.
(optional) The scope originally specified for the handler.
Removes listeners that were added by the mon method.
Removes listeners that were added by the mon method.
The item from which to remove a listener/listeners.
The event name, or an object containing event name properties.
Optional. If the ename parameter was an event name, this
is the handler function.
Optional. If the ename parameter was an event name, this
is the scope (this reference) 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.
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
The new model. Can be either the model name string, or a reference to the model's constructor
Sets the new model on the associated Store, if one is present
Sets the Proxy's Reader by string, config object or Reader instance
Sets the Proxy's Reader by string, config object or Reader instance
The new Reader, which can be either a type string, a configuration object or an Ext.data.reader.Reader instance
The attached Reader object
Sets the Proxy's Writer by string, config object or Writer instance
Sets the Proxy's Writer by string, config object or Writer instance
The new Writer, which can be either a type string, a configuration object or an Ext.data.writer.Writer instance
The attached Writer object
Suspend the firing of all events. (see resumeEvents)
Suspend the firing of all events. (see resumeEvents)
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.)
Removes an event handler (shorthand for removeListener.)
The type of event the handler was associated with.
The handler to remove. This must be a reference to the function passed into the addListener call.
(optional) The scope originally specified for the handler.