- 效果
端对端的纯文本聊天互通，是在webRTC（十四）：webrtc 端到端文本聊天基础上，将音视频信息去除以后得到的结果。
具体代码如下
- html
<html>
<head>
<title>WebRTC PeerConnection</title>
<style>
.preview{
display: flex;
}
.remote{
margin-left: 20px;
}
.text_chat{
display: flex;
}
.text_chat textarea{
width: 350px;
height: 350px;
}
.send{
margin-top: 20px;
}
</style>
</head>
<body>
<div>
<div>
<button id="connserver">Connect Sig Server</button>
<button id="leave" disabled>Leave</button>
</div>
<!--文本聊天-->
<h2>Chat:</h2>
<div class="text_chat">
<div>
<textarea id="chat" disabled></textarea>
</div>
<div class="remote">
<textarea id="sendtext" disabled></textarea>
</div>
</div>
<div class="send">
<button id="send" disabled>Send</button>
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.3/socket.io.js"></script>
<script src="https://webrtc.github.io/adapter/adapter-latest.js"></script>
<script src="./js/client.js"></script>
</body>
</html>
- js
'use strict'
var btnConn = document.querySelector('button#connserver');
var btnLeave = document.querySelector('button#leave');
// 文本聊天
var chat = document.querySelector('textarea#chat');
var send_txt = document.querySelector('textarea#sendtext');
var btnSend = document.querySelector('button#send');
var roomid = '888888';
var socket =null;
var state = 'init';
var pc = null;
var dc = null;
var pcConfig={
'iceServers':[{
'urls':'turn:121.41.76.43:3478',
'credential':'123456',
'username':'huang'
}]
}
function sendMessage(roomid,data){
if(socket){
socket.emit('message',roomid,data);
}
}
function getAnswer(desc){
pc.setLocalDescription(desc);
sendMessage(roomid,desc);
}
function handleAnswerError(err){
console.error('Failed to get Answer!',err);
}
function getOffer(desc){
pc.setLocalDescription(desc);
sendMessage(roomid,desc)
}
function handleOfferError(err){
console.error('Failed to get Offer!',err);
}
//接收远端流通道
function call(){
if(state === 'joined_conn'){
if(pc){
var options = {
offerToReceiveAudio:1,
offerToReceiveVideo:1
}
pc.createOffer(options)
.then(getOffer)
.catch(handleOfferError);
}
}
}
// 第一步：开始服务
function connSignalServer(){
conn();
return true;
}
//文本对方传过来的数据
function reveivemsg(e){
var msg = e.data;
if(msg){
chat.value += '->' + msg + '\r\n';
}else{
console.error('recreived msg is null');
}
}
function dataChannelStateChange(){
var readyState=dc.readyState;
if(readyState==='open'){
send_txt.disabled =false;
btnSend.disabled=false;
}else{
send_txt.disabled = true;
btnSend.disabled =true;
}
}
function conn(){
//1 触发socke连接
socket = io.connect();
//2 加入房间后的回调
socket.on('joined',(roomid,id)=>{
state = 'joined';
createPeerConnection();
btnConn.disabled = true;
btnLeave.disabled =false;
console.log("reveive joined message:state=",state);
});
socket.on('otherjoin',(roomid,id)=>{
if (state === 'joined_unbind') {
createPeerConnection();
}
//文本聊天
// dc=pc.createDataChannel('chatchannel');
var dataChannelOptions = {
ordered: true, //保证到达顺序
};
dc=pc.createDataChannel('dataChannel',dataChannelOptions);
dc.onmessage=reveivemsg;
dc.onopen = dataChannelStateChange;
dc.onclose = dataChannelStateChange;
state = 'joined_conn';
//媒体协商
call();
console.log("reveive otherjoin message:state=",state);
});
socket.on('full',(roomid,id)=>{
console.log('receive full message ', roomid, id);
closePeerConnection();
state = 'leaved';
btnConn.disabled = false;
btnLeave.disabled = true;
console.log("reveive full message:state=",state);
alert("the room is full!");
});
socket.on('leaved',(roomid,id)=>{
state = 'leaved';
socket.disconnect();
btnConn.disabled = false;
btnLeave.disabled = true;
console.log("reveive leaved message:state=",state);
});
socket.on('bye',(roomid,id)=>{
state = 'joined_unbind';
closePeerConnection();
console.log("reveive bye message:state=",state);
});
socket.on('disconnect', (socket) => {
console.log('receive disconnect message!', roomid);
if(!(state === 'leaved')){
closePeerConnection();
}
state = 'leaved';
});
socket.on('message',(roomid,id,data)=>{
console.log(" message=====>",data);
//媒体协商
if(data){
if(data.type === 'offer'){
pc.setRemoteDescription(new RTCSessionDescription(data));
pc.createAnswer()
.then(getAnswer)
.catch(handleAnswerError);
}else if(data.type === 'answer'){
console.log("reveive client message=====>",data);
pc.setRemoteDescription(new RTCSessionDescription(data));
}else if(data.type === 'candidate'){
var candidate = new RTCIceCandidate({
sdpMLineIndex:data.label,
candidate:data.candidate
});
pc.addIceCandidate(candidate);
}else{
console.error('the message is invalid!',data)
}
}
console.log("reveive client message",roomid,id,data);
});
socket.emit('join',roomid);
return;
}
function leave(){
if(socket){
socket.emit('leave',roomid);
}
//释放资源
closePeerConnection();
btnConn.disabled = false;
btnLeave.disabled = true;
}
//创建本地流媒体链接
function createPeerConnection(){
console.log('create RTCPeerConnection!');
if(!pc){
pc = new RTCPeerConnection(pcConfig);
pc.onicecandidate = (e) =>{
if(e.candidate){
sendMessage(roomid,{
type:'candidate',
label:e.candidate.sdpMLineIndex,
id:e.candidate.sdpMid,
candidate:e.candidate.candidate
});
}
}
//文本聊天
pc.ondatachannel = e =>{
// if(!dc){
dc= e.channel;
dc.onmessage =reveivemsg;
dc.onopen = dataChannelStateChange;
dc.onclose = dataChannelStateChange;
// }
}
}
if(pc === null || pc === undefined){
console.error('pc is null or undefined!');
return;
}
}
//关闭本地媒体流链接
function closePeerConnection(){
console.log('close RTCPeerConnection!');
if(pc){
pc.close();
pc = null;
}
}
//发送文本
function sendText(){
var data = send_txt.value;
if(data){
dc.send(data);
}
send_txt.value="";
chat.value += '<-' +data+'\r\n';
}
btnConn.onclick = connSignalServer;
btnLeave.onclick = leave;
btnSend.onclick=sendText;
