joynr.messaging.webmessaging.WebMessagingSkeleton.js Maven / Gradle / Ivy

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There is a newer version: 1.4.0
/*
 * #%L
 * %%
 * Copyright (C) 2011 - 2015 BMW Car IT GmbH
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

define(
        "joynr/messaging/webmessaging/WebMessagingSkeleton",
        [ "joynr/util/UtilInternal"
        ],
        function(Util) {

            /**
             * @constructor WebMessagingSkeleton
             * @param {Object} settings the settings object for this constructor call
             * @param {Window} settings.window the window to register the event handler at
             */
            function WebMessagingSkeleton(settings) {
                Util.checkProperty(settings, "Object", "settings");

                if (settings.window === undefined) {
                    throw new Error(
                            "WebMessagingSkeleton constructor parameter windows is undefined");
                }

                if (settings.window.addEventListener === undefined
                    || settings.window.removeEventListener === undefined) {
                    throw new Error(
                            "WebMessagingSkeleton constructor parameter window does not provide the expected functions \"addEventListener\" and \"removeEventListener\"");
                }

                var receiverCallbacks = [];
                var callbackFct = function(event) {
                    Util.fire(receiverCallbacks, event.data);
                };

                settings.window.addEventListener("message", callbackFct);

                /**
                 * Registers a listener for web messaging
                 * @function WebMessagingSkeleton#registerListener
                 *
                 * @param {Function} listener the listener function receiving the messaging events events with the signature "function(joynrMessage) {..}"
                 */
                this.registerListener = function registerListener(listener) {
                    Util.checkPropertyIfDefined(listener, "Function", "listener");

                    receiverCallbacks.push(listener);
                };

                /**
                 * Unregisters a listener for web messaging
                 * @function WebMessagingSkeleton#unregisterListener
                 *
                 * @param {Function} listener the listener function receiving the messaging events events with the signature "function(joynrMessage) {..}"
                 */
                this.unregisterListener = function unregisterListener(listener) {
                    Util.checkPropertyIfDefined(listener, "Function", "listener");

                    Util.removeElementFromArray(receiverCallbacks, listener);
                };

                /**
                 * @function WebMessagingSkeleton#shutdown
                 */
                this.shutdown = function shutdown() {
                    settings.window.removeEventListener("message", callbackFct);
                };

            }

            return WebMessagingSkeleton;

        });