+ <pre class="prettyprint lang-js"><span id='Ext-data-proxy-Ajax-method-constructor'><span id='Ext-data-proxy-Ajax'>/**
+</span></span> * @author Ed Spencer
+ *
+ * AjaxProxy is one of the most widely-used ways of getting data into your application. It uses AJAX requests to load
+ * data from the server, usually to be placed into a {@link Ext.data.Store Store}. Let's take a look at a typical setup.
+ * Here we're going to set up a Store that has an AjaxProxy. To prepare, we'll also set up a {@link Ext.data.Model
+ * Model}:
+ *
+ * Ext.define('User', {
+ * extend: 'Ext.data.Model',
+ * fields: ['id', 'name', 'email']
+ * });
+ *
+ * //The Store contains the AjaxProxy as an inline configuration
+ * var store = Ext.create('Ext.data.Store', {
+ * model: 'User',
+ * proxy: {
+ * type: 'ajax',
+ * url : 'users.json'
+ * }
+ * });
+ *
+ * store.load();
+ *
+ * Our example is going to load user data into a Store, so we start off by defining a {@link Ext.data.Model Model} with
+ * the fields that we expect the server to return. Next we set up the Store itself, along with a
+ * {@link Ext.data.Store#proxy proxy} configuration. This configuration was automatically turned into an
+ * Ext.data.proxy.Ajax instance, with the url we specified being passed into AjaxProxy's constructor.
+ * It's as if we'd done this:
+ *
+ * new Ext.data.proxy.Ajax({
+ * url: 'users.json',
+ * model: 'User',
+ * reader: 'json'
+ * });
+ *
+ * A couple of extra configurations appeared here - {@link #model} and {@link #reader}. These are set by default when we
+ * create the proxy via the Store - the Store already knows about the Model, and Proxy's default {@link
+ * Ext.data.reader.Reader Reader} is {@link Ext.data.reader.Json JsonReader}.
+ *
+ * Now when we call store.load(), the AjaxProxy springs into action, making a request to the url we configured
+ * ('users.json' in this case). As we're performing a read, it sends a GET request to that url (see
+ * {@link #actionMethods} to customize this - by default any kind of read will be sent as a GET request and any kind of write
+ * will be sent as a POST request).
+ *
+ * # Limitations
+ *
+ * AjaxProxy cannot be used to retrieve data from other domains. If your application is running on http://domainA.com it
+ * cannot load data from http://domainB.com because browsers have a built-in security policy that prohibits domains
+ * talking to each other via AJAX.
+ *
+ * If you need to read data from another domain and can't set up a proxy server (some software that runs on your own
+ * domain's web server and transparently forwards requests to http://domainB.com, making it look like they actually came
+ * from http://domainA.com), you can use {@link Ext.data.proxy.JsonP} and a technique known as JSON-P (JSON with
+ * Padding), which can help you get around the problem so long as the server on http://domainB.com is set up to support
+ * JSON-P responses. See {@link Ext.data.proxy.JsonP JsonPProxy}'s introduction docs for more details.
+ *
+ * # Readers and Writers
+ *
+ * AjaxProxy can be configured to use any type of {@link Ext.data.reader.Reader Reader} to decode the server's response.
+ * If no Reader is supplied, AjaxProxy will default to using a {@link Ext.data.reader.Json JsonReader}. Reader
+ * configuration can be passed in as a simple object, which the Proxy automatically turns into a {@link
+ * Ext.data.reader.Reader Reader} instance:
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * model: 'User',
+ * reader: {
+ * type: 'xml',
+ * root: 'users'
+ * }
+ * });
+ *
+ * proxy.getReader(); //returns an {@link Ext.data.reader.Xml XmlReader} instance based on the config we supplied
+ *
+ * # Url generation
+ *
+ * AjaxProxy automatically inserts any sorting, filtering, paging and grouping options into the url it generates for
+ * each request. These are controlled with the following configuration options:
+ *
+ * - {@link #pageParam} - controls how the page number is sent to the server (see also {@link #startParam} and {@link #limitParam})
+ * - {@link #sortParam} - controls how sort information is sent to the server
+ * - {@link #groupParam} - controls how grouping information is sent to the server
+ * - {@link #filterParam} - controls how filter information is sent to the server
+ *
+ * Each request sent by AjaxProxy is described by an {@link Ext.data.Operation Operation}. To see how we can customize
+ * the generated urls, let's say we're loading the Proxy with the following Operation:
+ *
+ * var operation = new Ext.data.Operation({
+ * action: 'read',
+ * page : 2
+ * });
+ *
+ * Now we'll issue the request for this Operation by calling {@link #read}:
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * url: '/users'
+ * });
+ *
+ * proxy.read(operation); //GET /users?page=2
+ *
+ * Easy enough - the Proxy just copied the page property from the Operation. We can customize how this page data is sent
+ * to the server:
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * url: '/users',
+ * pagePage: 'pageNumber'
+ * });
+ *
+ * proxy.read(operation); //GET /users?pageNumber=2
+ *
+ * Alternatively, our Operation could have been configured to send start and limit parameters instead of page:
+ *
+ * var operation = new Ext.data.Operation({
+ * action: 'read',
+ * start : 50,
+ * limit : 25
+ * });
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * url: '/users'
+ * });
+ *
+ * proxy.read(operation); //GET /users?start=50&limit;=25
+ *
+ * Again we can customize this url:
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * url: '/users',
+ * startParam: 'startIndex',
+ * limitParam: 'limitIndex'
+ * });
+ *
+ * proxy.read(operation); //GET /users?startIndex=50&limitIndex;=25
+ *
+ * AjaxProxy will also send sort and filter information to the server. Let's take a look at how this looks with a more
+ * expressive Operation object:
+ *
+ * var operation = new Ext.data.Operation({
+ * action: 'read',
+ * sorters: [
+ * new Ext.util.Sorter({
+ * property : 'name',
+ * direction: 'ASC'
+ * }),
+ * new Ext.util.Sorter({
+ * property : 'age',
+ * direction: 'DESC'
+ * })
+ * ],
+ * filters: [
+ * new Ext.util.Filter({
+ * property: 'eyeColor',
+ * value : 'brown'
+ * })
+ * ]
+ * });
+ *
+ * This is the type of object that is generated internally when loading a {@link Ext.data.Store Store} with sorters and
+ * filters defined. By default the AjaxProxy will JSON encode the sorters and filters, resulting in something like this
+ * (note that the url is escaped before sending the request, but is left unescaped here for clarity):
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * url: '/users'
+ * });
+ *
+ * proxy.read(operation); //GET /users?sort=[{"property":"name","direction":"ASC"},{"property":"age","direction":"DESC"}]&filter;=[{"property":"eyeColor","value":"brown"}]
+ *
+ * We can again customize how this is created by supplying a few configuration options. Let's say our server is set up
+ * to receive sorting information is a format like "sortBy=name#ASC,age#DESC". We can configure AjaxProxy to provide
+ * that format like this:
+ *
+ * var proxy = new Ext.data.proxy.Ajax({
+ * url: '/users',
+ * sortParam: 'sortBy',
+ * filterParam: 'filterBy',
+ *
+ * //our custom implementation of sorter encoding - turns our sorters into "name#ASC,age#DESC"
+ * encodeSorters: function(sorters) {
+ * var length = sorters.length,
+ * sortStrs = [],
+ * sorter, i;
+ *
+ * for (i = 0; i < length; i++) {
+ * sorter = sorters[i];
+ *
+ * sortStrs[i] = sorter.property + '#' + sorter.direction
+ * }
+ *
+ * return sortStrs.join(",");
+ * }
+ * });
+ *
+ * proxy.read(operation); //GET /users?sortBy=name#ASC,age#DESC&filterBy;=[{"property":"eyeColor","value":"brown"}]
+ *
+ * We can also provide a custom {@link #encodeFilters} function to encode our filters.
+ *
+ * @constructor
+ * Note that if this HttpProxy is being used by a {@link Ext.data.Store Store}, then the Store's call to
+ * {@link Ext.data.Store#load load} will override any specified callback and params options. In this case, use the
+ * {@link Ext.data.Store Store}'s events to modify parameters, or react to loading events.
+ *
+ * @param {Object} config (optional) Config object.
+ * If an options parameter is passed, the singleton {@link Ext.Ajax} object will be used to make the request.