/**
* @author Ed Spencer
* @aside guide proxies
*
* 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',
* config: {
* 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:
*
* Ext.create('Ext.data.proxy.Ajax', {
* config: {
* 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 = Ext.create('Ext.data.proxy.Ajax', {
* config: {
* 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 = Ext.create('Ext.data.Operation', {
* action: 'read',
* page : 2
* });
*
* Now we'll issue the request for this Operation by calling {@link #read}:
*
* var proxy = Ext.create('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 = Ext.create('Ext.data.proxy.Ajax', {
* url: '/users',
* pageParam: '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 = Ext.create('Ext.data.Operation', {
* action: 'read',
* start : 50,
* limit : 25
* });
*
* var proxy = Ext.create('Ext.data.proxy.Ajax', {
* url: '/users'
* });
*
* proxy.read(operation); // GET /users?start=50&limit;=25
*
* Again we can customize this url:
*
* var proxy = Ext.create('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 = Ext.create('Ext.data.Operation', {
* action: 'read',
* sorters: [
* Ext.create('Ext.util.Sorter', {
* property : 'name',
* direction: 'ASC'
* }),
* Ext.create('Ext.util.Sorter', {
* property : 'age',
* direction: 'DESC'
* })
* ],
* filters: [
* Ext.create('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 = Ext.create('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 = Ext.create('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#method-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.
*/
Ext.define('Ext.data.proxy.Ajax', {
extend: 'Ext.data.proxy.Server',
requires: ['Ext.util.MixedCollection', 'Ext.Ajax'],
alias: 'proxy.ajax',
alternateClassName: ['Ext.data.HttpProxy', 'Ext.data.AjaxProxy'],
config: {
/**
* @cfg {Boolean} withCredentials
* This configuration is sometimes necessary when using cross-origin resource sharing.
* @accessor
*/
withCredentials: false,
* @cfg {Boolean} useDefaultXhrHeader
* Set this to false to not send the default Xhr header (X-Requested-With) with every request.
* This should be set to false when making CORS (cross-domain) requests.
* @accessor
*/
useDefaultXhrHeader: true,
/**
* @cfg {String} username
* Most oData feeds require basic HTTP authentication. This configuration allows
* you to specify the username.
* @accessor
*/
username: null,
/**
* @cfg {String} password
* Most oData feeds require basic HTTP authentication. This configuration allows
* you to specify the password.
* @accessor
*/
password: null,
/**
* @property {Object} actionMethods
* Mapping of action name to HTTP request method. In the basic AjaxProxy these are set to
* 'GET' for 'read' actions and 'POST' for 'create', 'update' and 'destroy' actions.
* The {@link Ext.data.proxy.Rest} maps these to the correct RESTful methods.
*/
actionMethods: {
create : 'POST',
read : 'GET',
update : 'POST',
destroy: 'POST'
},
* @cfg {Object} [headers=undefined]
* Any headers to add to the Ajax request.
*/
headers: {}
},
/**
* Performs Ajax request.
* @protected
* @param {Ext.data.Operation} operation
* @param {Function} callback
* @param {Object} scope
* @return {Object}
*/
doRequest: function(operation, callback, scope) {
var me = this,
writer = me.getWriter(),
request = me.buildRequest(operation);
request.setConfig({
headers: me.getHeaders(),
timeout: me.getTimeout(),
method: me.getMethod(request),
callback: me.createRequestCallback(request, operation, callback, scope),
scope: me,
proxy: me,
useDefaultXhrHeader: me.getUseDefaultXhrHeader()
});
if (operation.getWithCredentials() || me.getWithCredentials()) {
request.setWithCredentials(true);
request.setUsername(me.getUsername());
request.setPassword(me.getPassword());
}
// We now always have the writer prepare the request
request = writer.write(request);
Ext.Ajax.request(request.getCurrentConfig());
return request;
},
/**
* Returns the HTTP method name for a given request. By default this returns based on a lookup on
* {@link #actionMethods}.
* @param {Ext.data.Request} request The request object.
* @return {String} The HTTP method to use (should be one of 'GET', 'POST', 'PUT' or 'DELETE').
*/
getMethod: function(request) {
return this.getActionMethods()[request.getAction()];
},
/**
* @private
* @param {Ext.data.Request} request The Request object.
* @param {Ext.data.Operation} operation The Operation being executed.
* @param {Function} callback The callback function to be called when the request completes.
* This is usually the callback passed to `doRequest`.
* @param {Object} scope The scope in which to execute the callback function.
* @return {Function} The callback function.
*/
createRequestCallback: function(request, operation, callback, scope) {
var me = this;
return function(options, success, response) {
me.processResponse(success, operation, request, response, callback, scope);
};
}
});