websocket.js

/*
    This program is distributed under the terms of the MIT license.
    Please see the LICENSE file for details.

    Copyright 2006-2008, OGG, LLC
*/

/* jshint undef: true, unused: true:, noarg: true, latedef: true */
/* global define, window, clearTimeout, WebSocket, DOMParser, Strophe, $build */

(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        define('strophe-websocket', ['strophe-core'], function (core) {
            return factory(
                core.Strophe,
                core.$build
            );
        });
    } else {
        // Browser globals
        return factory(Strophe, $build);
    }
}(this, function (Strophe, $build) {

/** Class: Strophe.WebSocket
 *  _Private_ helper class that handles WebSocket Connections
 *
 *  The Strophe.WebSocket class is used internally by Strophe.Connection
 *  to encapsulate WebSocket sessions. It is not meant to be used from user's code.
 */

/** File: websocket.js
 *  A JavaScript library to enable XMPP over Websocket in Strophejs.
 *
 *  This file implements XMPP over WebSockets for Strophejs.
 *  If a Connection is established with a Websocket url (ws://...)
 *  Strophe will use WebSockets.
 *  For more information on XMPP-over-WebSocket see RFC 7395:
 *  http://tools.ietf.org/html/rfc7395
 *
 *  WebSocket support implemented by Andreas Guth (andreas.guth@rwth-aachen.de)
 */

/** PrivateConstructor: Strophe.Websocket
 *  Create and initialize a Strophe.WebSocket object.
 *  Currently only sets the connection Object.
 *
 *  Parameters:
 *    (Strophe.Connection) connection - The Strophe.Connection that will use WebSockets.
 *
 *  Returns:
 *    A new Strophe.WebSocket object.
 */
Strophe.Websocket = function(connection) {
    this._conn = connection;
    this.strip = "wrapper";

    var service = connection.service;
    if (service.indexOf("ws:") !== 0 && service.indexOf("wss:") !== 0) {
        // If the service is not an absolute URL, assume it is a path and put the absolute
        // URL together from options, current URL and the path.
        var new_service = "";

        if (connection.options.protocol === "ws" && window.location.protocol !== "https:") {
            new_service += "ws";
        } else {
            new_service += "wss";
        }

        new_service += "://" + window.location.host;

        if (service.indexOf("/") !== 0) {
            new_service += window.location.pathname + service;
        } else {
            new_service += service;
        }

        connection.service = new_service;
    }
};

Strophe.Websocket.prototype = {
    /** PrivateFunction: _buildStream
     *  _Private_ helper function to generate the <stream> start tag for WebSockets
     *
     *  Returns:
     *    A Strophe.Builder with a <stream> element.
     */
    _buildStream: function ()
    {
        return $build("open", {
            "xmlns": Strophe.NS.FRAMING,
            "to": this._conn.domain,
            "version": '1.0'
        });
    },

    /** PrivateFunction: _check_streamerror
     * _Private_ checks a message for stream:error
     *
     *  Parameters:
     *    (Strophe.Request) bodyWrap - The received stanza.
     *    connectstatus - The ConnectStatus that will be set on error.
     *  Returns:
     *     true if there was a streamerror, false otherwise.
     */
    _check_streamerror: function (bodyWrap, connectstatus) {
        var errors = bodyWrap.getElementsByTagNameNS(Strophe.NS.STREAM, "error");
        if (errors.length === 0) {
            return false;
        }
        var error = errors[0];

        var condition = "";
        var text = "";

        var ns = "urn:ietf:params:xml:ns:xmpp-streams";
        for (var i = 0; i < error.childNodes.length; i++) {
            var e = error.childNodes[i];
            if (e.nodeType === 3) {
                text = e.textContent;
            } else if (e.getAttribute("xmlns") !== ns) {
                break;
            } else {
                condition = e.nodeName;
            }
        }

        var errorString = "WebSocket stream error: ";

        if (condition) {
            errorString += condition;
        } else {
            errorString += "unknown";
        }

        if (text) {
            errorString += " - " + condition;
        }

        Strophe.error(errorString);

        // close the connection on stream_error
        this._conn._changeConnectStatus(connectstatus, condition);
        if (condition) {
            this._conn._doDisconnect();
        }
        return true;
    },

    /** PrivateFunction: _reset
     *  Reset the connection.
     *
     *  This function is called by the reset function of the Strophe Connection.
     *  Is not needed by WebSockets.
     */
    _reset: function ()
    {
        return;
    },

    /** PrivateFunction: _connect
     *  _Private_ function called by Strophe.Connection.connect
     *
     *  Creates a WebSocket for a connection and assigns Callbacks to it.
     *  Does nothing if there already is a WebSocket.
     */
    _connect: function () {
        // Ensure that there is no open WebSocket from a previous Connection.
        this._closeSocket();

        // Create the new WobSocket
        this.socket = new WebSocket(this._conn.service, "xmpp");
        this.socket.onopen = this._onOpen.bind(this);
        this.socket.onerror = this._onError.bind(this);
        this.socket.onclose = this._onClose.bind(this);
        this.socket.onmessage = this._connect_cb_wrapper.bind(this);
    },

    /** PrivateFunction: _connect_cb
     *  _Private_ function called by Strophe.Connection._connect_cb
     *
     * checks for stream:error
     *
     *  Parameters:
     *    (Strophe.Request) bodyWrap - The received stanza.
     */
    _connect_cb: function(bodyWrap) {
        var error = this._check_streamerror(bodyWrap, Strophe.Status.CONNFAIL);
        if (error) {
            return Strophe.Status.CONNFAIL;
        }
    },

    /** PrivateFunction: _handleStreamStart
     * _Private_ function that checks the opening <open /> tag for errors.
     *
     * Disconnects if there is an error and returns false, true otherwise.
     *
     *  Parameters:
     *    (Node) message - Stanza containing the <open /> tag.
     */
    _handleStreamStart: function(message) {
        var error = false;

        // Check for errors in the <open /> tag
        var ns = message.getAttribute("xmlns");
        if (typeof ns !== "string") {
            error = "Missing xmlns in <open />";
        } else if (ns !== Strophe.NS.FRAMING) {
            error = "Wrong xmlns in <open />: " + ns;
        }

        var ver = message.getAttribute("version");
        if (typeof ver !== "string") {
            error = "Missing version in <open />";
        } else if (ver !== "1.0") {
            error = "Wrong version in <open />: " + ver;
        }

        if (error) {
            this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, error);
            this._conn._doDisconnect();
            return false;
        }

        return true;
    },

    /** PrivateFunction: _connect_cb_wrapper
     * _Private_ function that handles the first connection messages.
     *
     * On receiving an opening stream tag this callback replaces itself with the real
     * message handler. On receiving a stream error the connection is terminated.
     */
    _connect_cb_wrapper: function(message) {
        if (message.data.indexOf("<open ") === 0 || message.data.indexOf("<?xml") === 0) {
            // Strip the XML Declaration, if there is one
            var data = message.data.replace(/^(<\?.*?\?>\s*)*/, "");
            if (data === '') return;

            var streamStart = new DOMParser().parseFromString(data, "text/xml").documentElement;
            this._conn.xmlInput(streamStart);
            this._conn.rawInput(message.data);

            //_handleStreamSteart will check for XML errors and disconnect on error
            if (this._handleStreamStart(streamStart)) {
                //_connect_cb will check for stream:error and disconnect on error
                this._connect_cb(streamStart);
            }
        } else if (message.data.indexOf("<close ") === 0) { //'<close xmlns="urn:ietf:params:xml:ns:xmpp-framing />') {
            this._conn.rawInput(message.data);
            this._conn.xmlInput(message);
            var see_uri = message.getAttribute("see-other-uri");
            if (see_uri) {
                this._conn._changeConnectStatus(Strophe.Status.REDIRECT, "Received see-other-uri, resetting connection");
                this._conn.reset();
                this._conn.service = see_uri;
                this._connect();
            } else {
                this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "Received closing stream");
                this._conn._doDisconnect();
            }
        } else {
            var string = this._streamWrap(message.data);
            var elem = new DOMParser().parseFromString(string, "text/xml").documentElement;
            this.socket.onmessage = this._onMessage.bind(this);
            this._conn._connect_cb(elem, null, message.data);
        }
    },

    /** PrivateFunction: _disconnect
     *  _Private_ function called by Strophe.Connection.disconnect
     *
     *  Disconnects and sends a last stanza if one is given
     *
     *  Parameters:
     *    (Request) pres - This stanza will be sent before disconnecting.
     */
    _disconnect: function (pres)
    {
        if (this.socket && this.socket.readyState !== WebSocket.CLOSED) {
            if (pres) {
                this._conn.send(pres);
            }
            var close = $build("close", { "xmlns": Strophe.NS.FRAMING, });
            this._conn.xmlOutput(close);
            var closeString = Strophe.serialize(close);
            this._conn.rawOutput(closeString);
            try {
                this.socket.send(closeString);
            } catch (e) {
                Strophe.info("Couldn't send <close /> tag.");
            }
        }
        this._conn._doDisconnect();
    },

    /** PrivateFunction: _doDisconnect
     *  _Private_ function to disconnect.
     *
     *  Just closes the Socket for WebSockets
     */
    _doDisconnect: function ()
    {
        Strophe.info("WebSockets _doDisconnect was called");
        this._closeSocket();
    },

    /** PrivateFunction _streamWrap
     *  _Private_ helper function to wrap a stanza in a <stream> tag.
     *  This is used so Strophe can process stanzas from WebSockets like BOSH
     */
    _streamWrap: function (stanza)
    {
        return "<wrapper>" + stanza + '</wrapper>';
    },


    /** PrivateFunction: _closeSocket
     *  _Private_ function to close the WebSocket.
     *
     *  Closes the socket if it is still open and deletes it
     */
    _closeSocket: function ()
    {
        if (this.socket) { try {
            this.socket.close();
        } catch (e) {} }
        this.socket = null;
    },

    /** PrivateFunction: _emptyQueue
     * _Private_ function to check if the message queue is empty.
     *
     *  Returns:
     *    True, because WebSocket messages are send immediately after queueing.
     */
    _emptyQueue: function ()
    {
        return true;
    },

    /** PrivateFunction: _onClose
     * _Private_ function to handle websockets closing.
     *
     * Nothing to do here for WebSockets
     */
    _onClose: function() {
        if(this._conn.connected && !this._conn.disconnecting) {
            Strophe.error("Websocket closed unexcectedly");
            this._conn._doDisconnect();
        } else {
            Strophe.info("Websocket closed");
        }
    },

    /** PrivateFunction: _no_auth_received
     *
     * Called on stream start/restart when no stream:features
     * has been received.
     */
    _no_auth_received: function (_callback)
    {
        Strophe.error("Server did not send any auth methods");
        this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "Server did not send any auth methods");
        if (_callback) {
            _callback = _callback.bind(this._conn);
            _callback();
        }
        this._conn._doDisconnect();
    },

    /** PrivateFunction: _onDisconnectTimeout
     *  _Private_ timeout handler for handling non-graceful disconnection.
     *
     *  This does nothing for WebSockets
     */
    _onDisconnectTimeout: function () {},

    /** PrivateFunction: _abortAllRequests
     *  _Private_ helper function that makes sure all pending requests are aborted.
     */
    _abortAllRequests: function () {},

    /** PrivateFunction: _onError
     * _Private_ function to handle websockets errors.
     *
     * Parameters:
     * (Object) error - The websocket error.
     */
    _onError: function(error) {
        Strophe.error("Websocket error " + error);
        this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "The WebSocket connection could not be established was disconnected.");
        this._disconnect();
    },

    /** PrivateFunction: _onIdle
     *  _Private_ function called by Strophe.Connection._onIdle
     *
     *  sends all queued stanzas
     */
    _onIdle: function () {
        var data = this._conn._data;
        if (data.length > 0 && !this._conn.paused) {
            for (var i = 0; i < data.length; i++) {
                if (data[i] !== null) {
                    var stanza, rawStanza;
                    if (data[i] === "restart") {
                        stanza = this._buildStream().tree();
                    } else {
                        stanza = data[i];
                    }
                    rawStanza = Strophe.serialize(stanza);
                    this._conn.xmlOutput(stanza);
                    this._conn.rawOutput(rawStanza);
                    if(this.socket)
                        this.socket.send(rawStanza);
                }
            }
            this._conn._data = [];
        }
    },

    /** PrivateFunction: _onMessage
     * _Private_ function to handle websockets messages.
     *
     * This function parses each of the messages as if they are full documents. [TODO : We may actually want to use a SAX Push parser].
     *
     * Since all XMPP traffic starts with "<stream:stream version='1.0' xml:lang='en' xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' id='3697395463' from='SERVER'>"
     * The first stanza will always fail to be parsed...
     * Addtionnaly, the seconds stanza will always be a <stream:features> with the stream NS defined in the previous stanza... so we need to 'force' the inclusion of the NS in this stanza!
     *
     * Parameters:
     * (string) message - The websocket message.
     */
    _onMessage: function(message) {
        var elem, data;
        // check for closing stream
        var close = '<close xmlns="urn:ietf:params:xml:ns:xmpp-framing" />';
        if (message.data === close) {
            this._conn.rawInput(close);
            this._conn.xmlInput(message);
            if (!this._conn.disconnecting) {
                this._conn._doDisconnect();
            }
            return;
        } else if (message.data.search("<open ") === 0) {
            // This handles stream restarts
            elem = new DOMParser().parseFromString(message.data, "text/xml").documentElement;

            if (!this._handleStreamStart(elem)) {
                return;
            }
        } else {
            data = this._streamWrap(message.data);
            elem = new DOMParser().parseFromString(data, "text/xml").documentElement;
        }

        if (this._check_streamerror(elem, Strophe.Status.ERROR)) {
            return;
        }

        //handle unavailable presence stanza before disconnecting
        if (this._conn.disconnecting &&
                elem.firstChild.nodeName === "presence" &&
                elem.firstChild.getAttribute("type") === "unavailable") {
            this._conn.xmlInput(elem);
            this._conn.rawInput(Strophe.serialize(elem));
            // if we are already disconnecting we will ignore the unavailable stanza and
            // wait for the </stream:stream> tag before we close the connection
            return;
        }
        this._conn._dataRecv(elem, message.data);
    },

    /** PrivateFunction: _onOpen
     * _Private_ function to handle websockets connection setup.
     *
     * The opening stream tag is sent here.
     */
    _onOpen: function() {
        Strophe.info("Websocket open");
        var start = this._buildStream();
        this._conn.xmlOutput(start.tree());

        var startString = Strophe.serialize(start);
        this._conn.rawOutput(startString);
        this.socket.send(startString);
    },

    /** PrivateFunction: _reqToData
     * _Private_ function to get a stanza out of a request.
     *
     * WebSockets don't use requests, so the passed argument is just returned.
     *
     *  Parameters:
     *    (Object) stanza - The stanza.
     *
     *  Returns:
     *    The stanza that was passed.
     */
    _reqToData: function (stanza)
    {
        return stanza;
    },

    /** PrivateFunction: _send
     *  _Private_ part of the Connection.send function for WebSocket
     *
     * Just flushes the messages that are in the queue
     */
    _send: function () {
        this._conn.flush();
    },

    /** PrivateFunction: _sendRestart
     *
     *  Send an xmpp:restart stanza.
     */
    _sendRestart: function ()
    {
        clearTimeout(this._conn._idleTimeout);
        this._conn._onIdle.bind(this._conn)();
    }
};
return Strophe;
}));