从导出的模块（node.js）访问函数

Question

I have been reading up on this and apprently there are more ways to export a module in node.js.

One of the simple things you can do with modules is to encapsulate functions within a file like so:

module.exports = {
  sayHelloInEnglish: function() {
    return "HELLO";
  },

  sayHelloInSpanish: function() {
    return "Hola";
  }
};

However i would like to create some more dirverse modules and so ive created the following user module:

    var UserModule = function (socket) {
    var userList = [];

    socket.on('userData', function (userDetails) {
        userDetails.socket = socket;
        userList[userDetails.id] = userDetails
    });

    socket.on('getActiveUsers', function () {
        socket.emit('activeUsers', userList);
    });

    function helloWorld (){
        console.log('hello world');
    }

};

module.exports = function (socket) {
    return new UserModule(socket);
};

now i am requireing this module in my io instance:

    io.on('connection', function (socket) {
    var my_user = userList.id;
    socket.on('userData', function (userDetails) {
        userDetails.socket = socket;
        userList[userDetails.id] = userDetails
    });


    var userModule = require('./costum_modules/UserModule.js')(socket);
    userModule.helloWorld();
    var chatModule = require('./costum_modules/ChatModule.js')(socket, userModule);
    var cacheModule = require('./costum_modules/CacheModule.js')(socket, userModule);
    var notificationModule = require('./costum_modules/NotificationModule')(socket, sequelize, userList);

});

The socket.on methods are working fine in my UserModule however i am unable to call the function helloWorld . if i try i get the following error:

userModule.helloWorld is not a function

So my question is, is what i am trying to do even possible? how am i able to store objects , functions ect in a module for later use?

Answer 1

function helloWorld is essentially a private function for use within your userModule.

You can make it public by changing the function declaration to the following:

this.helloWorld = function (){
    console.log('hello world');
}