--- /dev/null
+/**
+ * @author Ed Spencer
+ *
+ * The JsonP proxy 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 {@link Ext.data.proxy.Ajax 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 JsonP proxy. JsonP proxy 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.
+ *
+ * JsonP proxy 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 {@link Ext.data.proxy.Ajax AjaxProxy}. Here's how
+ * we might set that up:
+ *
+ * Ext.define('User', {
+ * extend: 'Ext.data.Model',
+ * config: {
+ * fields: ['id', 'name', 'email']
+ * }
+ * });
+ *
+ * var store = Ext.create('Ext.data.Store', {
+ * model: 'User',
+ * proxy: {
+ * type: 'jsonp',
+ * url : 'http://domainB.com/users'
+ * }
+ * });
+ *
+ * store.load();
+ *
+ * That's all we need to do - JsonP proxy 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=callback1"></script>
+ *
+ * # Customization
+ *
+ * This script tag can be customized using the {@link #callbackKey} configuration. For example:
+ *
+ * var store = Ext.create('Ext.data.Store', {
+ * model: 'User',
+ * proxy: {
+ * type: 'jsonp',
+ * url : 'http://domainB.com/users',
+ * callbackKey: 'theCallbackFunction'
+ * }
+ * });
+ *
+ * store.load();
+ *
+ * Would inject a script tag like this:
+ *
+ * <script src="http://domainB.com/users?theCallbackFunction=callback1"></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);
+ *
+ * ###Further Reading
+ * [Sencha Touch Data Overview](../../../core_concepts/data/data_package_overview.html)
+ * [Sencha Touch Store Guide](../../../core_concepts/data/stores.html)
+ * [Sencha Touch Models Guide](../../../core_concepts/data/models.html)
+ * [Sencha Touch Proxy Guide](../../../core_concepts/data/proxies.html)
+ */
+Ext.define('Ext.data.proxy.JsonP', {
+ extend: 'Ext.data.proxy.Server',
+ alternateClassName: 'Ext.data.ScriptTagProxy',
+ alias: ['proxy.jsonp', 'proxy.scripttag'],
+ requires: ['Ext.data.JsonP'],
+
+ config: {
+ defaultWriterType: 'base',
+
+ /**
+ * @cfg {String} callbackKey
+ * See {@link Ext.data.JsonP#callbackKey}.
+ * @accessor
+ */
+ callbackKey : 'callback',
+
+ /**
+ * @cfg {String} recordParam
+ * The param name to use when passing records to the server (e.g. 'records=someEncodedRecordString').
+ * @accessor
+ */
+ recordParam: 'records',
+
+ /**
+ * @cfg {Boolean} autoAppendParams
+ * `true` to automatically append the request's params to the generated url.
+ * @accessor
+ */
+ autoAppendParams: true
+ },
+
+ /**
+ * Performs the read request to the remote domain. JsonP proxy does not actually create an Ajax request,
+ * instead we write out a `<script>` tag based on the configuration of the internal Ext.data.Request object
+ * @param {Ext.data.Operation} operation The {@link Ext.data.Operation Operation} object to execute.
+ * @param {Function} callback A callback function to execute when the Operation has been completed.
+ * @param {Object} scope The scope to execute the callback in.
+ * @return {Object}
+ * @protected
+ */
+ doRequest: function(operation, callback, scope) {
+ // <debug>
+ var action = operation.getAction();
+ if (action !== 'read') {
+ Ext.Logger.error('JsonP proxies can only be used to read data.');
+ }
+ // </debug>
+
+ //generate the unique IDs for this request
+ var me = this,
+ request = me.buildRequest(operation),
+ params = request.getParams();
+
+ // apply JsonP proxy-specific attributes to the Request
+ request.setConfig({
+ callbackKey: me.getCallbackKey(),
+ timeout: me.getTimeout(),
+ scope: me,
+ callback: me.createRequestCallback(request, operation, callback, scope)
+ });
+
+ // Prevent doubling up because the params are already added to the url in buildUrl
+ if (me.getAutoAppendParams()) {
+ request.setParams({});
+ }
+
+ request.setJsonP(Ext.data.JsonP.request(request.getCurrentConfig()));
+
+ // Set the params back once we have made the request though
+ request.setParams(params);
+
+ operation.setStarted();
+
+ me.lastRequest = request;
+
+ return request;
+ },
+
+ /**
+ * @private
+ * Creates and returns the function that is called when the request has completed. The returned function
+ * should accept a Response object, which contains the response to be read by the configured Reader.
+ * The third argument is the callback that should be called after the request has been completed and the Reader has decoded
+ * the response. This callback will typically be the callback passed by a store, e.g. in proxy.read(operation, theCallback, scope)
+ * theCallback refers to the callback argument received by this function.
+ * See {@link #doRequest} for details.
+ * @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(success, response, errorType) {
+ delete me.lastRequest;
+ me.processResponse(success, operation, request, response, callback, scope);
+ };
+ },
+
+ // @inheritdoc
+ setException: function(operation, response) {
+ operation.setException(operation.getRequest().getJsonP().errorType);
+ },
+
+
+ /**
+ * Generates a url based on a given Ext.data.Request object. Adds the params and callback function name to the url
+ * @param {Ext.data.Request} request The request object.
+ * @return {String} The url.
+ */
+ buildUrl: function(request) {
+ var me = this,
+ url = me.callParent(arguments),
+ params = Ext.apply({}, request.getParams()),
+ filters = params.filters,
+ filter, i, value;
+
+ delete params.filters;
+
+ if (me.getAutoAppendParams()) {
+ url = Ext.urlAppend(url, Ext.Object.toQueryString(params));
+ }
+
+ if (filters && filters.length) {
+ for (i = 0; i < filters.length; i++) {
+ filter = filters[i];
+ value = filter.getValue();
+ if (value) {
+ url = Ext.urlAppend(url, filter.getProperty() + "=" + value);
+ }
+ }
+ }
+
+ return url;
+ },
+
+ /**
+ * @inheritdoc
+ */
+ destroy: function() {
+ this.abort();
+ this.callParent(arguments);
+ },
+
+ /**
+ * Aborts the current server request if one is currently running.
+ */
+ abort: function() {
+ var lastRequest = this.lastRequest;
+ if (lastRequest) {
+ Ext.data.JsonP.abort(lastRequest.getJsonP());
+ }
+ }
+});
projects / sencha-touch.git / blobdiff