add extjs 6.0.1 sources

[extjs.git] / extjs / packages / legacy / modern / src / device / communicator / Default.js

/**\r
 * @private\r
 *\r
 * This object handles communication between the WebView and Sencha's native shell.\r
 * Currently it has two primary responsibilities:\r
 *\r
 * 1. Maintaining unique string ids for callback functions, together with their scope objects\r
 * 2. Serializing given object data into HTTP GET request parameters\r
 *\r
 * As an example, to capture a photo from the device's camera, we use `Ext.device.Camera.capture()` like:\r
 *\r
 *     Ext.device.Camera.capture(\r
 *         function(dataUri){\r
 *             // Do something with the base64-encoded `dataUri` string\r
 *         },\r
 *         function(errorMessage) {\r
 *\r
 *         },\r
 *         callbackScope,\r
 *         {\r
 *             quality: 75,\r
 *             width: 500,\r
 *             height: 500\r
 *         }\r
 *     );\r
 *\r
 * Internally, `Ext.device.Communicator.send()` will then be invoked with the following argument:\r
 *\r
 *     Ext.device.Communicator.send({\r
 *         command: 'Camera#capture',\r
 *         callbacks: {\r
 *             onSuccess: function() {\r
 *                 // ...\r
 *             },\r
 *             onError: function() {\r
 *                 // ...\r
 *             }\r
 *         },\r
 *         scope: callbackScope,\r
 *         quality: 75,\r
 *         width: 500,\r
 *         height: 500\r
 *     });\r
 *\r
 * Which will then be transformed into a HTTP GET request, sent to native shell's local\r
 * HTTP server with the following parameters:\r
 *\r
 *     ?quality=75&width=500&height=500&command=Camera%23capture&onSuccess=3&onError=5\r
 *\r
 * Notice that `onSuccess` and `onError` have been converted into string ids (`3` and `5`\r
 * respectively) and maintained by `Ext.device.Communicator`.\r
 *\r
 * Whenever the requested operation finishes, `Ext.device.Communicator.invoke()` simply needs\r
 * to be executed from the native shell with the corresponding ids given before. For example:\r
 *\r
 *     Ext.device.Communicator.invoke('3', ['DATA_URI_OF_THE_CAPTURED_IMAGE_HERE']);\r
 *\r
 * will invoke the original `onSuccess` callback under the given scope. (`callbackScope`), with\r
 * the first argument of 'DATA_URI_OF_THE_CAPTURED_IMAGE_HERE'\r
 *\r
 * Note that `Ext.device.Communicator` maintains the uniqueness of each function callback and\r
 * its scope object. If subsequent calls to `Ext.device.Communicator.send()` have the same\r
 * callback references, the same old ids will simply be reused, which guarantee the best possible\r
 * performance for a large amount of repetitive calls.\r
 */\r
Ext.define('Ext.device.communicator.Default', {\r
\r
    SERVER_URL: 'http://localhost:3000', // Change this to the correct server URL\r
\r
    callbackDataMap: {},\r
\r
    callbackIdMap: {},\r
\r
    idSeed: 0,\r
\r
    globalScopeId: '0',\r
\r
    generateId: function() {\r
        return String(++this.idSeed);\r
    },\r
\r
    getId: function(object) {\r
        var id = object.$callbackId;\r
\r
        if (!id) {\r
            object.$callbackId = id = this.generateId();\r
        }\r
\r
        return id;\r
    },\r
\r
    getCallbackId: function(callback, scope) {\r
        var idMap = this.callbackIdMap,\r
            dataMap = this.callbackDataMap,\r
            id, scopeId, callbackId, data;\r
\r
        if (!scope) {\r
            scopeId = this.globalScopeId;\r
        } else if (scope.isIdentifiable) {\r
            scopeId = scope.getId();\r
        } else {\r
            scopeId = this.getId(scope);\r
        }\r
\r
        callbackId = this.getId(callback);\r
\r
        if (!idMap[scopeId]) {\r
            idMap[scopeId] = {};\r
        }\r
\r
        if (!idMap[scopeId][callbackId]) {\r
            id = this.generateId();\r
            data = {\r
                callback: callback,\r
                scope: scope\r
            };\r
\r
            idMap[scopeId][callbackId] = id;\r
            dataMap[id] = data;\r
        }\r
\r
        return idMap[scopeId][callbackId];\r
    },\r
\r
    getCallbackData: function(id) {\r
        return this.callbackDataMap[id];\r
    },\r
\r
    invoke: function(id, args) {\r
        var data = this.getCallbackData(id);\r
\r
        data.callback.apply(data.scope, args);\r
    },\r
\r
    send: function(args) {\r
        var callbacks, scope, name, callback;\r
\r
        if (!args) {\r
            args = {};\r
        } else if (args.callbacks) {\r
            callbacks = args.callbacks;\r
            scope = args.scope;\r
\r
            delete args.callbacks;\r
            delete args.scope;\r
\r
            for (name in callbacks) {\r
                if (callbacks.hasOwnProperty(name)) {\r
                    callback = callbacks[name];\r
\r
                    if (typeof callback == 'function') {\r
                        args[name] = this.getCallbackId(callback, scope);\r
                    }\r
                }\r
            }\r
        }\r
\r
        args.__source = document.location.href;\r
\r
        var result = this.doSend(args);\r
\r
        return (result && result.length > 0) ? JSON.parse(result) : null;\r
    },\r
\r
    doSend: function(args) {\r
        var xhr = new XMLHttpRequest();\r
\r
        xhr.open('GET', this.SERVER_URL + '?' + Ext.Object.toQueryString(args) + '&_dc=' + new Date().getTime(), false);\r
\r
        // wrap the request in a try/catch block so we can check if any errors are thrown and attempt to call any\r
        // failure/callback functions if defined\r
        try {\r
            xhr.send(null);\r
\r
            return xhr.responseText;\r
        } catch(e) {\r
            if (args.failure) {\r
                this.invoke(args.failure);\r
            } else if (args.callback) {\r
                this.invoke(args.callback);\r
            }\r
        }\r
    }\r
});\r