gallery-2009.10.25-22.02.41 lsmith gallery-jsonp

src/gallery-jsonp/build.properties

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+builddir=../../../builder/componentbuild
+component=gallery-jsonp
+component.jsfiles=jsonp.js
+component.requires=selector-css3

src/gallery-jsonp/build.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project name="YUI" default="local">
+    <property file="build.properties" />
+    <import file="${builddir}/3.x/bootstrap.xml" 
+            description="Default Build Properties and Targets" />
+</project>

src/gallery-jsonp/js/jsonp.js

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+var l    = Y.Lang,
+    noop = function () {};
+
+/**
+ * <p>Provides a JSONPRequest class for repeated JSONP calls, and a convenience
+ * method Y.jsonp(url, callback) to instantiate and send a JSONP request.</p>
+ *
+ * <p>The url of the JSONP service will have a proxy function assigned as the
+ * callback name.  By default it will look for callback=(anything).  If
+ * (anything) is present, it will be clobbered by the proxy name.  And if the
+ * callback= param can't be found, it will be appended to the url.</p>
+ *
+ * <p>To override this behavior, pass a function to the &quot;format&quot;
+ * property in the callback config.</p>
+ *
+ * <p>The second parameter can be a callback function that accepts the JSON
+ * payload as its argument, or a configuration object supporting the keys:</p>
+ * <ul>
+ *   <li>success - function handler for successful transmission</li>
+ *   <li>failure - function handler for failed transmission</li>
+ *   <li>format - function for inserting the proxy name into the url</li>
+ * </ul>
+ *
+ * @module gallery-jsonp
+ * @class JSONPRequest
+ * @constructor
+ * @param url {String} the url of the JSONP service
+ * @param callback {Object|Function} the callback configuration or success
+ *                     handler
+ */
+function JSONPRequest(url,callback) {
+
+    this.url = url;
+
+    this._init(callback);
+}
+
+/**
+ * RegExp used by the default URL formatter to insert the generated callback
+ * name into the JSONP url.  Looks for a query param callback=.  If a value is
+ * assigned, it will be clobbered.
+ *
+ * @member JSONPRequest._pattern
+ * @type RegExp
+ * @default /\bcallback=.*?(?=&|$)/i
+ * @protected
+ * @static
+ */
+JSONPRequest._pattern = /\bcallback=.*?(?=&|$)/i;
+
+/**
+ * Template used by the default URL formatter to add the callback function name
+ * to the url.
+ *
+ * @member JSONPRequest._template
+ * @type String
+ * @default "callback={callback}"
+ * @protected
+ * @static
+ */
+JSONPRequest._template = "callback={callback}";
+
+JSONPRequest.prototype = {
+    /**
+     * Set up the success and failure handlers and the regex pattern used
+     * to insert the temporary callback name in the url.
+     *
+     * @method _init
+     * @param cfg {Object|Function} The success callback or the config
+     *                  object containing success and failure functions and
+     *                  the url regex.
+     * @protected
+     */
+    _init : function (cfg) {
+        var c = l.isObject(cfg) ? cfg : {};
+
+        this.success = l.isFunction(c) ?
+            c :
+            l.isFunction(c.success) ?
+                c.success :
+                noop;
+
+        this.failure = l.isFunction(c.failure) ? c.failure : noop;
+
+        if (l.isFunction(c.format)) {
+            this._format = c.format;
+        }
+    },
+
+    /**
+     * Default url formatter.  Looks for callback= in the url and appends it
+     * if not present.  The supplied proxy name will be assigned to the query
+     * param.  Override this method by passing a function as the
+     * &quot;format&quot; property in the config object to the constructor.
+     *
+     * @method _format
+     * @param proxy {String} the function name that will be used as a proxy to
+     *      the configured callback methods.
+     * @return {String} fully qualified JSONP url
+     * @protected
+     */
+    _format: function (proxy) {
+        var url       = this.url,
+            callback  = JSONPRequest._template.replace(/\{callback\}/, proxy),
+            c;
+
+        if (JSONPRequest._pattern.test(url)) {
+            return url.replace(JSONPRequest._pattern, callback);
+        } else {
+            c = url.slice(-1);
+            if (c !== '&' && c !== '?') {
+                url += (url.indexOf('?') > -1) ? '&' : '?';
+            }
+            return url + callback;
+        }
+    },
+
+    /** 
+     * Issues the JSONP request.
+     *
+     * @method send
+     * @chainable
+     */
+    send : function () {
+        var proxy   = Y.guid().replace(/-/g,'_'),
+            url     = this._format('YUI.' + proxy),
+            success = this.success,
+            failure = this.failure;
+
+        // Temporary un-sandboxed function alias
+        YUI[proxy] = success;
+
+        // Use the YUI instance's Get util to add the script and trigger the
+        // callback.
+        YUI({ modules: { _ : { fullpath : url } } }).
+        use('_', function(X,res) {
+            delete YUI[proxy];
+
+            var el = Y.Selector.query('head > script[src*='+proxy+']',null,true);
+            if (el) {
+                el.parentNode.removeChild(el);
+            } else {
+                Y.log('JSONP script element not found for cleanup','warn','jsonp');
+            }
+
+            if (!res.success) {
+                failure(url);
+            }
+        });
+
+        return this;
+    }
+};
+
+Y.JSONPRequest = JSONPRequest;
+
+/**
+ *
+ * @method Y.jsonp
+ * @param url {String} the url of the JSONP service with the {callback}
+ *          placeholder where the callback function name typically goes.
+ * @param c {Function|Object} Callback function accepting the JSON payload
+ *          as its argument, or a configuration object (see above).
+ * @return {JSONPRequest}
+ * @static
+ */
+Y.jsonp = function (url,c) {
+    var req = new Y.JSONPRequest(url,c);
+
+    // returns null if invalid inputs
+    return req && req.send();
+};