366 lines
14 KiB
JavaScript
366 lines
14 KiB
JavaScript
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// MIT License:
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//
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// Copyright (c) 2010-2012, Joe Walnes
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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/**
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* This behaves like a WebSocket in every way, except if it fails to connect,
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* or it gets disconnected, it will repeatedly poll until it successfully connects
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* again.
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*
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* It is API compatible, so when you have:
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* ws = new WebSocket('ws://....');
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* you can replace with:
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* ws = new ReconnectingWebSocket('ws://....');
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*
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* The event stream will typically look like:
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* onconnecting
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* onopen
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* onmessage
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* onmessage
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* onclose // lost connection
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* onconnecting
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* onopen // sometime later...
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* onmessage
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* onmessage
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* etc...
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*
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* It is API compatible with the standard WebSocket API, apart from the following members:
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*
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* - `bufferedAmount`
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* - `extensions`
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* - `binaryType`
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*
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* Latest version: https://github.com/joewalnes/reconnecting-websocket/
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* - Joe Walnes
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*
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* Syntax
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* ======
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* var socket = new ReconnectingWebSocket(url, protocols, options);
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*
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* Parameters
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* ==========
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* url - The url you are connecting to.
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* protocols - Optional string or array of protocols.
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* options - See below
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*
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* Options
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* =======
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* Options can either be passed upon instantiation or set after instantiation:
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*
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* var socket = new ReconnectingWebSocket(url, null, { debug: true, reconnectInterval: 4000 });
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*
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* or
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*
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* var socket = new ReconnectingWebSocket(url);
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* socket.debug = true;
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* socket.reconnectInterval = 4000;
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*
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* debug
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* - Whether this instance should log debug messages. Accepts true or false. Default: false.
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*
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* automaticOpen
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* - Whether or not the websocket should attempt to connect immediately upon instantiation. The socket can be manually opened or closed at any time using ws.open() and ws.close().
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*
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* reconnectInterval
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* - The number of milliseconds to delay before attempting to reconnect. Accepts integer. Default: 1000.
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*
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* maxReconnectInterval
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* - The maximum number of milliseconds to delay a reconnection attempt. Accepts integer. Default: 30000.
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*
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* reconnectDecay
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* - The rate of increase of the reconnect delay. Allows reconnect attempts to back off when problems persist. Accepts integer or float. Default: 1.5.
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*
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* timeoutInterval
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* - The maximum time in milliseconds to wait for a connection to succeed before closing and retrying. Accepts integer. Default: 2000.
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*
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*/
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(function (global, factory) {
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if (typeof define === 'function' && define.amd) {
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define([], factory);
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} else if (typeof module !== 'undefined' && module.exports){
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module.exports = factory();
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} else {
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global.ReconnectingWebSocket = factory();
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}
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})(this, function () {
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if (!('WebSocket' in window)) {
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return;
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}
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function ReconnectingWebSocket(url, protocols, options) {
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// Default settings
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var settings = {
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/** Whether this instance should log debug messages. */
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debug: false,
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/** Whether or not the websocket should attempt to connect immediately upon instantiation. */
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automaticOpen: true,
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/** The number of milliseconds to delay before attempting to reconnect. */
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reconnectInterval: 1000,
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/** The maximum number of milliseconds to delay a reconnection attempt. */
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maxReconnectInterval: 30000,
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/** The rate of increase of the reconnect delay. Allows reconnect attempts to back off when problems persist. */
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reconnectDecay: 1.5,
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/** The maximum time in milliseconds to wait for a connection to succeed before closing and retrying. */
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timeoutInterval: 2000,
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/** The maximum number of reconnection attempts to make. Unlimited if null. */
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maxReconnectAttempts: null,
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/** The binary type, possible values 'blob' or 'arraybuffer', default 'blob'. */
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binaryType: 'blob'
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}
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if (!options) { options = {}; }
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// Overwrite and define settings with options if they exist.
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for (var key in settings) {
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if (typeof options[key] !== 'undefined') {
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this[key] = options[key];
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} else {
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this[key] = settings[key];
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}
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}
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// These should be treated as read-only properties
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/** The URL as resolved by the constructor. This is always an absolute URL. Read only. */
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this.url = url;
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/** The number of attempted reconnects since starting, or the last successful connection. Read only. */
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this.reconnectAttempts = 0;
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/**
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* The current state of the connection.
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* Can be one of: WebSocket.CONNECTING, WebSocket.OPEN, WebSocket.CLOSING, WebSocket.CLOSED
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* Read only.
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*/
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this.readyState = WebSocket.CONNECTING;
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/**
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* A string indicating the name of the sub-protocol the server selected; this will be one of
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* the strings specified in the protocols parameter when creating the WebSocket object.
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* Read only.
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*/
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this.protocol = null;
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// Private state variables
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var self = this;
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var ws;
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var forcedClose = false;
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var timedOut = false;
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var eventTarget = document.createElement('div');
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// Wire up "on*" properties as event handlers
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eventTarget.addEventListener('open', function(event) { self.onopen(event); });
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eventTarget.addEventListener('close', function(event) { self.onclose(event); });
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eventTarget.addEventListener('connecting', function(event) { self.onconnecting(event); });
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eventTarget.addEventListener('message', function(event) { self.onmessage(event); });
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eventTarget.addEventListener('error', function(event) { self.onerror(event); });
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// Expose the API required by EventTarget
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this.addEventListener = eventTarget.addEventListener.bind(eventTarget);
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this.removeEventListener = eventTarget.removeEventListener.bind(eventTarget);
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this.dispatchEvent = eventTarget.dispatchEvent.bind(eventTarget);
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/**
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* This function generates an event that is compatible with standard
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* compliant browsers and IE9 - IE11
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*
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* This will prevent the error:
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* Object doesn't support this action
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*
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* http://stackoverflow.com/questions/19345392/why-arent-my-parameters-getting-passed-through-to-a-dispatched-event/19345563#19345563
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* @param s String The name that the event should use
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* @param args Object an optional object that the event will use
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*/
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function generateEvent(s, args) {
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var evt = document.createEvent("CustomEvent");
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evt.initCustomEvent(s, false, false, args);
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return evt;
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};
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this.open = function (reconnectAttempt) {
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ws = new WebSocket(self.url, protocols || []);
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ws.binaryType = this.binaryType;
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if (reconnectAttempt) {
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if (this.maxReconnectAttempts && this.reconnectAttempts > this.maxReconnectAttempts) {
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return;
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}
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} else {
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eventTarget.dispatchEvent(generateEvent('connecting'));
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this.reconnectAttempts = 0;
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}
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'attempt-connect', self.url);
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}
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var localWs = ws;
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var timeout = setTimeout(function() {
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'connection-timeout', self.url);
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}
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timedOut = true;
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localWs.close();
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timedOut = false;
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}, self.timeoutInterval);
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ws.onopen = function(event) {
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clearTimeout(timeout);
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'onopen', self.url);
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}
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self.protocol = ws.protocol;
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self.readyState = WebSocket.OPEN;
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self.reconnectAttempts = 0;
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var e = generateEvent('open');
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e.isReconnect = reconnectAttempt;
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reconnectAttempt = false;
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eventTarget.dispatchEvent(e);
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};
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ws.onclose = function(event) {
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clearTimeout(timeout);
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ws = null;
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if (forcedClose) {
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self.readyState = WebSocket.CLOSED;
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eventTarget.dispatchEvent(generateEvent('close'));
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} else {
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self.readyState = WebSocket.CONNECTING;
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var e = generateEvent('connecting');
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e.code = event.code;
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e.reason = event.reason;
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e.wasClean = event.wasClean;
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eventTarget.dispatchEvent(e);
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if (!reconnectAttempt && !timedOut) {
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'onclose', self.url);
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}
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eventTarget.dispatchEvent(generateEvent('close'));
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}
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var timeout = self.reconnectInterval * Math.pow(self.reconnectDecay, self.reconnectAttempts);
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setTimeout(function() {
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self.reconnectAttempts++;
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self.open(true);
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}, timeout > self.maxReconnectInterval ? self.maxReconnectInterval : timeout);
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}
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};
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ws.onmessage = function(event) {
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'onmessage', self.url, event.data);
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}
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var e = generateEvent('message');
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e.data = event.data;
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eventTarget.dispatchEvent(e);
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};
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ws.onerror = function(event) {
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'onerror', self.url, event);
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}
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eventTarget.dispatchEvent(generateEvent('error'));
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};
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}
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// Whether or not to create a websocket upon instantiation
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if (this.automaticOpen == true) {
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this.open(false);
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}
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/**
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* Transmits data to the server over the WebSocket connection.
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*
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* @param data a text string, ArrayBuffer or Blob to send to the server.
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*/
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this.send = function(data) {
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if (ws) {
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if (self.debug || ReconnectingWebSocket.debugAll) {
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console.debug('ReconnectingWebSocket', 'send', self.url, data);
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}
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return ws.send(data);
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} else {
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throw 'INVALID_STATE_ERR : Pausing to reconnect websocket';
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}
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};
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/**
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* Closes the WebSocket connection or connection attempt, if any.
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* If the connection is already CLOSED, this method does nothing.
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*/
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this.close = function(code, reason) {
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// Default CLOSE_NORMAL code
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if (typeof code == 'undefined') {
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code = 1000;
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}
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forcedClose = true;
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if (ws) {
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ws.close(code, reason);
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}
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};
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/**
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* Additional public API method to refresh the connection if still open (close, re-open).
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* For example, if the app suspects bad data / missed heart beats, it can try to refresh.
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*/
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this.refresh = function() {
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if (ws) {
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ws.close();
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}
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};
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}
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/**
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* An event listener to be called when the WebSocket connection's readyState changes to OPEN;
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* this indicates that the connection is ready to send and receive data.
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*/
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ReconnectingWebSocket.prototype.onopen = function(event) {};
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/** An event listener to be called when the WebSocket connection's readyState changes to CLOSED. */
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ReconnectingWebSocket.prototype.onclose = function(event) {};
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/** An event listener to be called when a connection begins being attempted. */
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ReconnectingWebSocket.prototype.onconnecting = function(event) {};
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/** An event listener to be called when a message is received from the server. */
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ReconnectingWebSocket.prototype.onmessage = function(event) {};
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/** An event listener to be called when an error occurs. */
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ReconnectingWebSocket.prototype.onerror = function(event) {};
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/**
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* Whether all instances of ReconnectingWebSocket should log debug messages.
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* Setting this to true is the equivalent of setting all instances of ReconnectingWebSocket.debug to true.
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*/
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ReconnectingWebSocket.debugAll = false;
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ReconnectingWebSocket.CONNECTING = WebSocket.CONNECTING;
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ReconnectingWebSocket.OPEN = WebSocket.OPEN;
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ReconnectingWebSocket.CLOSING = WebSocket.CLOSING;
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ReconnectingWebSocket.CLOSED = WebSocket.CLOSED;
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return ReconnectingWebSocket;
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});
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