Vue uses WebSocket to simulate the chat function

var userNum = 0; //Count the number of online users var chatList = []; //Record chat history var WebSocketServer = require('ws').Server;
wss = new WebSocketServer({ port: 8181 }); //8181 corresponds to the front end //Call broadcast to achieve data intercommunication and real-time update wss.broadcast = function (msg) {
    wss.clients.forEach(function each(client) {
        client.send(msg);
    });
};
wss.on('connection', function (ws) {
    userNum++; //Connection established successfully, number of people online +1
    wss.broadcast(JSON.stringify({ funName: 'userCount', users: userNum, chat: chatList })); //Successful connection broadcasts the number of people currently online console.log('Connected clients:', userNum);
    //Receive data sent by the front end ws.on('message', function (e) {
        var resData = JSON.parse(e)
        console.log('Received a message from clent:' + resData.msg)
        chatList.push({ userId: resData.userId, content: resData.msg }); //Every time a message is sent, it will be stored and then broadcasted, so that each user who comes in can see the previous data wss.broadcast(JSON.stringify({ userId: resData.userId, msg: resData.msg })); //Each message sent is equivalent to broadcasting a message });
    ws.on('close', function (e) {
        userNum--; //Establish connection and close the number of people online - 1
        wss.broadcast(JSON.stringify({ funName: 'userCount', users: userNum, chat: chatList })); //Establish connection and close broadcast once. Current number of online clients console.log('Connected clients:', userNum);
        console.log('Long connection is closed')
    })
})
console.log('Server created successfully')

<template>
  <div class="chat-box">
    <header>Number of people in chat room: {{count}}</header>
    <div class="msg-box" ref="msg-box">
      <div
        v-for="(i,index) in list"
        :key="index"
        class="msg"
        :style="i.userId == userId?'flex-direction:row-reverse':''"
      >
        <div class="user-head">
          <div
            class="head"
            :style="` background: hsl(${getUserHead(i.userId,'bck')}, 88%, 62%); clip-path: polygon(${getUserHead(i.userId,'polygon')}% 0,100% 100%,0% 100%); transform: rotate(${getUserHead(i.userId,'rotate')}deg)`"
          ></div>
        </div>
        <div class="user-msg">
          <span
            :style="i.userId == userId?'float: right':''"
            :class="i.userId == userId?'right':'left'"
          >{{i.content}}</span>
        </div>
      </div>
    </div>
    <div class="input-box">
      <input type="text" ref="sendMsg" v-model="contentText" @keyup.enter="sendText()" />
      <div class="btn" :class="{['btn-active']:contentText}" @click="sendText()">Send</div>
    </div>
  </div>
</template>
 
<script>
export default {
  data() {
    return {
      ws: null,
      count: 0,
      userId: null, //Current user ID
      list: [], //array of chat records contentText: "", //input value};
  },
  created() {
    this.getUserID();
  },
  mounted() {
    this.initWebSocket();
  },
  methods: {
    //Use the timestamp as the current user ID
    getUserID() {
      let time = new Date().getTime();
      this.userId = time;
    },
    //Generate a random avatar based on userID getUserHead(id, type) {
      let ID = String(id);
      if (type == "bck") {
        return Number(ID.substring(ID.length - 3));
      }
      if (type == "polygon") {
        return Number(ID.substring(ID.length - 2));
      }
      if (type == "rotate") {
        return Number(ID.substring(ID.length - 3));
      }
    },
    //Scroll bar to the bottom scrollBottm() {
      let el = this.$refs["msg-box"];
      el.scrollTop = el.scrollHeight;
    },
    //Send chat message sendText() {
      let _this = this;
      _this.$refs["sendMsg"].focus();
      if (!_this.contentText) {
        return;
      }
      let params = {
        userId: _this.userId,
        msg: _this.contentText,
      };
      _this.ws.send(JSON.stringify(params)); //Call WebSocket send() to send information _this.contentText = "";
      setTimeout(() => {
        _this.scrollBottm();
      }, 500);
    },
    //Enter the page to create a websocket connection initWebSocket() {
      let _this = this;
      //Judge whether there is a websocket connection on the page if (window.WebSocket) {
        // The port number :8181 here should be consistent with the backend configuration let ws = new WebSocket("ws://192.168.5.42:9502"); 
        // let ws = new WebSocket("ws://192.168.5.8:8181"); //Here is my local test_this.ws = ws;
        ws.onopen = function (e) {
          console.log("Server connection successful");
        };
        ws.onclose = function (e) {
          console.log("Server connection closed");
        };
        ws.onerror = function () {
          console.log("Server connection error");
        };
        ws.onmessage = function (e) {
          //Receive data returned by the server let resData = JSON.parse(e.data);
          if (resData.funName == "userCount") {
            _this.count = resData.users;
            _this.list = resData.chat;
          } else {
            _this.list = [
              ..._this.list,
              { userId: resData.userId, content: resData.msg },
            ];
          }
        };
      }
    },
  },
};
</script>
 
<style lang="scss" scoped>
.chat-box {
  margin: 0 auto;
  background: #fafafa;
  position: absolute;
  height: 100%;
  width: 100%;
  // max-width: 700px;
  header {
    position: fixed;
    width: 100%;
    height: 3rem;
    background: #409eff;
    // max-width: 700px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: white;
    font-size: 1rem;
  }
  .msg-box {
    position: absolute;
    height: calc(100% - 6.5rem);
    width: 100%;
    margin-top: 3rem;
    overflow-y: scroll;
    .msg {
      width: 95%;
      min-height: 2.5rem;
      margin: 1rem 0.5rem;
      position: relative;
      display: flex;
      justify-content: flex-start !important;
      .user-head {
        min-width: 2.5rem;
        width: 20%;
        width: 2.5rem;
        height: 2.5rem;
        border-radius: 50%;
        background: #f1f1f1;
        display: flex;
        justify-content: center;
        align-items: center;
        .head {
          width: 1.2rem;
          height: 1.2rem;
        }
        // position: absolute;
      }
      .user-msg {
        width: 80%;
        // position: absolute;
        word-break: break-all;
        position: relative;
        z-index: 5;
        span {
          display: inline-block;
          padding: 0.5rem 0.7rem;
          border-radius: 0.5rem;
          margin-top: 0.2rem;
          font-size: 0.88rem;
        }
        .left {
          background: white;
          animation: toLeft 0.5s ease both 1;
        }
        .right {
          background: #53a8ff;
          color: white;
          animation: toright 0.5s ease both 1;
        }
        @keyframes toLeft {
          0% {
            opacity: 0;
            transform: translateX(-10px);
          }
          100% {
            opacity: 1;
            transform: translateX(0px);
          }
        }
        @keyframes toright {
          0% {
            opacity: 0;
            transform: translateX(10px);
          }
          100% {
            opacity: 1;
            transform: translateX(0px);
          }
        }
      }
    }
  }
  .input-box {
    padding: 0 0.5rem;
    position: absolute;
    bottom: 0;
    width: 97%;
    height: 3.5rem;
    background: #fafafa;
    box-shadow: 0 0 5px #ccc;
    display: flex;
    justify-content: space-between;
    align-items: center;
    input {
      height: 2.3rem;
      display: inline-block;
      width: 100%;
      padding: 0.5rem;
      border: none;
      border-radius: 0.2rem;
      font-size: 0.88rem;
    }
    .btn {
      height: 2.3rem;
      min-width: 4rem;
      background: #e0e0e0;
      padding: 0.5rem;
      font-size: 0.88rem;
      color: white;
      text-align: center;
      border-radius: 0.2rem;
      margin-left: 0.5rem;
      transition: 0.5s;
      line-height: 2.3rem;
    }
    .btn-active {
      background: #409eff;
    }
  }
}
</style>