Merge pull request #19 from AnalyticalGraphicsInc/refactor_jsonp

Replace JSONP implementation.

CHANGES

@@ -44,6 +44,8 @@ What's New
         * Renamed Tipsify.CalculateACMR to Tipsify.calculateACMR.
         * Renamed LeapSecond.CompareLeapSecondDate to LeapSecond.compareLeapSecondDate.
         * Geoscope.JSONP.get is now Cesium.jsonp.
+           * Cesium.jsonp now takes a url, a callback function, and an options object.  The
+             previous 2nd and 4th parameters are now specified using the options object.
         * TWEEN is no longer globally defined, and is instead available as Cesium.Tween.
         * Chain.js functions such as run are now moved to Cesium.Chain.run, etc.
         * Geoscope.CollectionAlgorithms.binarySearch is now Cesium.binarySearch.

LICENSE

@@ -78,14 +78,6 @@ chain.js
    OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-Lightweight-JSONP
-
-   https://github.com/IntoMethod/Lightweight-JSONP
-
-   Lightweight JSONP fetcher
-   Copyright 2010 Erik Karlsson. All rights reserved.
-   BSD licensed
-
 webgl-noise
 
    https://github.com/ashima/webgl-noise

Source/Core/createGuid.js

@@ -13,10 +13,11 @@ define(function() {
     function createGuid() {
         // http://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript
         return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
-            var r = Math.random() * 16 | 0, v = c === 'x' ? r : (r & 0x3 | 0x8);
+            var r = Math.random() * 16 | 0;
+            var v = c === 'x' ? r : (r & 0x3 | 0x8);
             return v.toString(16);
         });
     }
 
     return createGuid;
-});
+});

Source/Core/jsonp.js

@@ -0,0 +1,88 @@
+/*global define*/
+define(['./DeveloperError'], function(DeveloperError) {
+    'use strict';
+
+    function pushQueryParameter(array, name, value) {
+        array.push(encodeURIComponent(name) + '=' + encodeURIComponent(value));
+    }
+
+    /**
+     * Requests a resource using JSONP.
+     *
+     * @param {String} url The URL to request.
+     * @param {Function} callback The callback function to call, passing the requested resource as the single parameter.
+     * @param {Object} [options.parameters] Any extra query parameters to append to the URL.
+     * @param {String} [options.callbackParameterName='callback'] The callback parameter name that the server expects.
+     * @param {Object} [options.proxy] A proxy to use for the request. This object is expected to have a getURL function which returns the proxied URL, if needed.
+     */
+    function jsonp(url, callback, options) {
+        if (typeof url === 'undefined') {
+            throw new DeveloperError('url is required.', 'url');
+        }
+
+        if (typeof callback === 'undefined') {
+            throw new DeveloperError('callback is required.', 'callback');
+        }
+
+        options = typeof options !== 'undefined' ? options : {};
+
+        //generate a unique function name
+        var functionName;
+        do {
+            functionName = 'jsonp' + Math.random().toString().substring(2, 8);
+        } while (typeof window[functionName] !== 'undefined');
+
+        //assign a function with that name in the global scope
+        window[functionName] = function(data) {
+            callback(data);
+
+            try {
+                delete window[functionName];
+            } catch (e) {
+                window[functionName] = undefined;
+            }
+        };
+
+        var callbackParameterName = typeof options.callbackParameterName !== 'undefined' ? options.callbackParameterName : 'callback';
+        var queryParts = [];
+        pushQueryParameter(queryParts, callbackParameterName, functionName);
+
+        var parameters = options.parameters;
+        if (typeof parameters !== 'undefined') {
+            for ( var name in parameters) {
+                if (parameters.hasOwnProperty(name)) {
+                    pushQueryParameter(queryParts, name, parameters[name]);
+                }
+            }
+        }
+
+        if (queryParts.length > 0) {
+            if (url.indexOf('?') === -1) {
+                url += '?';
+            } else {
+                url += '&';
+            }
+
+            url += queryParts.join('&');
+        }
+
+        var proxy = options.proxy;
+        if (typeof proxy !== 'undefined') {
+            url = proxy.getURL(url);
+        }
+
+        var script = document.createElement('script');
+        script.async = true;
+        script.src = url;
+
+        var head = document.getElementsByTagName('head')[0];
+        script.onload = function() {
+            script.onload = undefined;
+            head.removeChild(script);
+        };
+
+        head.appendChild(script);
+    }
+
+    return jsonp;
+});

Source/Scene/ArcGISTileProvider.js

@@ -2,7 +2,7 @@
 define([
         '../Core/DeveloperError',
         '../Core/Math',
-        '../ThirdParty/jsonp',
+        '../Core/jsonp',
         './Projections'
     ], function(
         DeveloperError,
@@ -85,12 +85,7 @@ define([
          */
         this.service = desc.service;
 
-        /**
-         * A proxy to use for requests. This object is expected to have a getURL
-         * function which returns the proxied URL, if needed.
-         * @type {Object}
-         */
-        this.proxy = desc.proxy;
+        this._proxy = desc.proxy;
 
         // TODO: Get this information from the server
 
@@ -147,14 +142,7 @@ define([
         this._logoLoaded = false;
 
         var that = this;
-        var url = this._url;
-        if (typeof this.proxy !== 'undefined') {
-            url = this.proxy.getURL(url);
-        }
-
-        jsonp(url, {
-            f : 'json'
-        }, function(data) {
+        jsonp(this._url, function(data) {
             var credit = data.copyrightText;
 
             var canvas = document.createElement("canvas");
@@ -169,6 +157,11 @@ define([
 
             that._logo = canvas;
             that._logoLoaded = true;
+        }, {
+            parameters : {
+                f : 'json'
+            },
+            proxy : this._proxy
         });
     }
 
@@ -190,21 +183,13 @@ define([
         }
 
         var image = new Image();
-        if (onload && typeof onload === "function") {
-            image.onload = function() {
-                onload();
-            };
-        }
-        if (onerror && typeof onerror === "function") {
-            image.onerror = function() {
-                onerror();
-            };
-        }
+        image.onload = onload;
+        image.onerror = onerror;
         image.crossOrigin = '';
 
         var url = this._url + '/tile/' + tile.zoom + '/' + tile.y + '/' + tile.x;
-        if (typeof this.proxy !== 'undefined') {
-            url = this.proxy.getURL(url);
+        if (typeof this._proxy !== 'undefined') {
+            url = this._proxy.getURL(url);
         }
 
         image.src = url;