Example nodejs code for connecting to a webOS Smart TV

webos-ss-client.js

/*
 * Copyright (c) 2014 LG Electronics.
 *
 * 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.
 */

var events = require('events');
var WebSocket = require('ws');
var util = require('util');

if (process.version === 'v0.4.12') {
    // Hacks to make ws library run

    Buffer.prototype.readUInt32LE = function (offset, noAssert) {
        return this[offset] | (this[offset+1] << 8) | (this[offset+2] << 16) | (this[offset+3] << 24);
    };

    Buffer.prototype.writeUInt32LE = function (value, offset, noAssert) {
        this[offset] = value & 0xFF;
        this[offset+1] = (value >>> 8) & 0xFF;
        this[offset+2] = (value >>> 16) & 0xFF;
        this[offset+3] = (value >>> 24) & 0xFF;
    };

    function FakeBuffer () {
        throw new Error("This buffer type doesn't exist on this version of node");
    };

    global.ArrayBuffer = FakeBuffer;
    global.Uint8Array = FakeBuffer;
    global.Uint16Array = FakeBuffer;
    global.Uint32Array = FakeBuffer;
    global.Int8Array = FakeBuffer;
    global.Int16Array = FakeBuffer;
    global.Int32Array = FakeBuffer;
    global.Float32Array = FakeBuffer;
    global.Float64Array = FakeBuffer;
}

var Client = function () {
    events.EventEmitter.call(this);

    this.requestId = 1;
    this.requests = {};
    this.manifest = {
        permissions: ["LAUNCH", "CONTROL_AUDIO"]
    };
};

events.EventEmitter.call(Client);
util.inherits(Client, events.EventEmitter);

Client.prototype.connect = function (ip, cb) {
    if (cb) {
        var handler = function () {
            this.removeListener('connected', handler);
            this.removeListener('error', handler);
            this.removeListener('close', handler);

            cb();
        };

        this.on('connected', handler);
        this.on('error', handler);
        this.on('close', handler);
    }

    this.ws = new WebSocket("ws://" + ip + ":3000", {origin: "null"});

    this.ws.on('open', function () {
        console.log("opened");
        this.send({
            type: 'register',
            payload: {
                manifest: this.manifest
            }
        });
    }.bind(this));

    this.ws.on('message', function (data) {
        console.log("Received message: " + data);

        var message = JSON.parse(data);

        var request = message.id ? this.requests[message.id] : null;

        if (message.type === "response" || message.type === "error") {
            if (request) {
                if (request.callback) {
                    request.callback(message.payload);
                }

                if (!request.isSubscription) {
                    delete this.requests[request];
                }
            }
        } else if (message.type === "registered") {
            this.emit('connected');
        }
    }.bind(this));

    this.ws.on('error', function (err) {
        this.emit('error', err);
    }.bind(this));

    this.ws.on('close', function () {
        this.emit('close', 'connection closed');
    }.bind(this));
};

Client.prototype.send = function (obj) {
    console.log("Sending: " + JSON.stringify(obj));
    this.ws.send(JSON.stringify(obj));
};

Client.prototype.sendRequest = function (uri, payload, cb) {
    var requestId = this.requestId++;

    this.send({
        type: 'request',
        id: requestId,
        uri: uri,
        payload: payload || {}
    });

    this.requests[requestId] = {callback: cb};
};

function DeviceFinder () {
    events.EventEmitter.call(this);
    this.devices = {};
    this.startDiscovery();
};

util.inherits(DeviceFinder, events.EventEmitter);

DeviceFinder.prototype.getDeviceList = function () {
    return this.devices;
};

DeviceFinder.prototype.startDiscovery = function () {
    if (this.socket) {
        return;
    }

    var dgram = require('dgram');
    var socket = this.socket = dgram.createSocket('udp4');
    var sendSocket = dgram.createSocket('udp4');

    var sendSearch = this.sendSearch.bind(this);
    var cleanOld = function () {
        Object.keys(this.devices).forEach(function (ip) {
            var record = this.devices[ip];

            if (record && --record.ttl <= 0) {
                delete this.devices[ip];
                this.emit("lost", rinfo.address);
            }
        }, this);
    }.bind(this);

    socket.on('listening', function () {
        socket.setBroadcast(true);
        socket.addMembership('239.255.255.250');

        for (var i = 0; i < 3; i++) {
            setTimeout(function () {
                sendSearch();
            }, Math.random() * 1000);
        }

        this.rescanId = setInterval(function () {
            cleanOld();
            sendSearch();
        }, 10 * 1000);
    });

    socket.on('message', function (data, rinfo) {
        if (/^HTTP\/1.1 200 OK\r\n/.test(data) || /^NOTIFY \* HTTP\/1.1\r\n/.test(data)) {
            console.log("got response\n" + data);

            if (/USN:.*service:webos-second-screen/.test(data)) {
                if (/ssdp:byebye/.test(data)) {
                    delete this.devices[rinfo.address];
                    this.emit("lost", rinfo.address);
                } else {
                    var existing = this.devices[rinfo.address];
                    this.devices[rinfo.address] = {ttl: 2};

                    if (!existing) {
                        this.emit("found", rinfo.address);
                    }
                }
                this.emit("update");
            }
        }
    }.bind(this));

    socket.bind(0, '0.0.0.0');
};

DeviceFinder.prototype.sendSearch = function () {
    var data = "M-SEARCH * HTTP/1.1\r\n" +
        "Host: 239.255.255.250:1900\r\n" +
        "ST: urn:lge-com:service:webos-second-screen:1\r\n" +
        "MAN: \"ssdp:discover\"\r\n" +
        "MX: 5\r\n" +
        "\r\n";

    console.log("sending: " + data);
    var buffer = new Buffer(data, 'ascii');
    this.socket.send(buffer, 0, buffer.length, 1900, "239.255.255.250");
};

DeviceFinder.prototype.stopDiscovery = function () {
    if (this.socket) {
        this.socket.end();
        this.socket.destroy();
        this.socket = null;
    }

    if (this.rescanId) {
        clearInterval(this.rescanId);
        this.rescanId = null;
    }
};

function openBrowserOnTV(ip, url, cb) {
    var client = new Client();

    client.connect(ip, function (err) {
        if (err) {
            console.log("error connecting");
            cb(err);
            return;
        } else {
            console.log("connected");
        }

        client.sendRequest('ssap://system.launcher/open', {"target": url}, cb);
    });
}

function toggleMuteOnTV(ip, cb) {
    var client = new Client();

    client.connect(ip, function (err) {
        if (err) {
            console.log("error connecting");
            cb(err);
            return;
        } else {
            console.log("connected");
        }

        client.sendRequest('ssap://audio/getMute', {}, function (response) {
            client.sendRequest('ssap://audio/setMute', {"mute": !response.mute}, cb);
        });
    });
}

function openBrowserOnFirstWebOSTVFound() {
    var df = new DeviceFinder();

    df.startDiscovery();

    df.on('found', function (ip) {
        console.log("found TV ip: " + ip);
        openBrowserOnTV(ip, "http://www.connectsdk.com", function done (err) {
            if (err) {
                console.log("launch browser failed: " + JSON.stringify(err));
            } else {
                console.log("launch browser successful");
            }
            process.exit(0);
        });
    });
}

/*
toggleMuteOnTV("192.168.0.145", function (err) {
    if (err) {
        console.log("err: " + JSON.stringify(err));
    } else {
        console.log("success");
    }
    process.exit(0);
});
*/

openBrowserOnFirstWebOSTVFound();