如何获取Node.js类和socket.io事件上下文？ [英] How can I get Node.js class and socket.io event context?

问题描述

我在JavaScript类和socket.io'disconnect'事件中存在正确上下文的问题。

I have a Problem with the correct context in a JavaScript class and a socket.io 'disconnect' event.

我的类如下：

class GameSession {

   constructor(gameSessionId) {
       this._gameSessionId = gameSessionId;
       this._players = new Map();
   }

   addPlayer(socketId,player) {
       this._players.set(socketId,player);
       this.addListeners(player);
   }

   addListeners(player) {
       player.socket.on('disconnect',this.playerLeave);
   }

   playerLeave () {
       // ##### here is my Problem
   }
}

在 playerLeave功能中，我可以使用 this.id访问套接字ID。但是要访问 _players映射，我需要获得类的上下文，如果我将 addListeners函数更改为：

In the "playerLeave" function I can access the socket id with "this.id". But to access the "_players" map I need the context of the class which I get if I change the "addListeners" function to:

addListeners(player) {
    player.socket.on('disconnect',() => this.playerLeave());
}

但是，这样我松开了事件的上下文，因此可以调用

But by this I loose the context of the Event and so the possebility to call "this.id" to receive the socket id.

如何同时获得两者？

推荐答案

我遇到了同样的问题，并且找到了解决方案。 （我希望您也能找到它！）

I was facing the same issue, and I found a solution. (I hope you found it too!)

您只需要绑定两个实例：

You just have to bind both of instances like this:

   addListeners(player) {
       var playerSocket = player.socket;
       playerSocket.on('disconnect',this.playerLeave.bind(playerSocket, this));
   }

该类实例将作为参数传递给您的socketIO事件： / p>

And the class instance will be passed as a parameter in your socketIO event :

   playerLeave(gameSessionInstance) {
       console.log('Bye '+this.id);
       gameSessionInstance.removePlayer(this.id); // if you have a method called removePlayer for example
   }

这篇关于如何获取Node.js类和socket.io事件上下文？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！