如何设置socket.io以获取实时数据

Question

I'm new to mean-stack and I followed some instruction on how to get real-time data. I tried every single steps but none of it is working, how can I use socket.io correctly? I provided my code here for getting users from mongodb, please do correct my code

server.js

var express     = require ('express');
var app         = express();
var server      = require('http').Server(app);
var http        = require('http').Server(app);
var io          = require('socket.io')(http);
var morgan      = require ('morgan');
var mongoose    = require('mongoose');
var appRoutes   = require('./app/routes/api');

app.use(morgan('dev'));
app.use(bodyParser.json()); 
app.use(bodyParser.urlencoded({ extended: true })); 
app.use(express.static(__dirname + '/public'));
app.use('/api',appRoutes);

mongoose.connect('mongodb://localhost:27017/testing', function(err){
    if(err){
        console.log('Not connected' + err);
    } else
    {
        console.log('Connected');
    }
});

Then here is the part where I get the users from the table, I don't know how to get the the data real-time:

api.js

var User = require('../models/user');
const router = express.Router();
router.get('/management', function(req, res) {
        User.find({}, function(err, users) {
                if (!users) {
                    res.json({ success: false, message: 'Users not found' }); 
                } else {
                    res.json({ success: true, users: users,});
                }
        });
    });

userCtrl.js

.controller('managementCtrl', function(User, $scope) {
 function getUsers() { 
        User.getUsers().then(function(data) {
            if (data.data.success) {
                app.users = data.data.users;    
            } else {
                app.errorMsg = data.data.message; 
            }
        });
    }
});

userServices.js

angular.module('userServices', [])

.factory('User', function($http) {
 var userFactory = {}; 
 userFactory.getUsers = function() {
        return $http.get('/api/management/');
    };

 return userFactory;
    });

};

users.html

<tbody>
    <tr ng-repeat="person in management.users">
        <td align="center">{{ person.name }}</td>
        <td align="center">{{ person.email }}</td>
    </tr>
</tbody>

Answer 1

You have to make establish persistent socket connection with the frontEnd. After making the persistent connection you have to listen for the particular event and then send the realtime user Data.
You can achieve this by:

server.js

 var express     = require ('express');
var app         = express();
var server      = require('http').Server(app);
var http        = require('http').Server(app);
var io          = require('socket.io')(http);
var morgan      = require ('morgan');
var mongoose    = require('mongoose');
var appRoutes   = require('./app/routes/api');
var User = require('../models/user');

app.use(morgan('dev'));
app.use(bodyParser.json()); 
app.use(bodyParser.urlencoded({ extended: true })); 
app.use(express.static(__dirname + '/public'));
app.use('/api',appRoutes);

mongoose.connect('mongodb://localhost:27017/testing', function(err){
    if(err){
        console.log('Not connected' + err);
    } else
    {
        console.log('Connected');
    }
});

io.on('connection', function(socket) {
  console.log('New Socket has been connected');
  socket.on('getUserDetails', function() {
    User.find({}).then(function(data){
      socket.emit('userDetails', data)
   })
  })
})

In fronEnd you can emit the event getUserDetails for getting the data from the server and listen on userDetails for getting the response from the server.

Something like this can be implemented in front end angular