Using arrow functions with socket.io

Question

I was wondering how arrow functions can be used to replace bind. It was my understanding the I could use the arrow function to lexically call this in a function, but the function doesn't even get called anymore.

The strange thing is I don't get any errors, if I use the arrow function it just fails silently.

constructor(socket: SocketIO.Socket
{
    // Works
    socket.on(this.onLogin.name, this.onLogin.bind(this));

    // Doesn't work?
    socket.on(this.onLogin.name, (data: LoginDetails) => this.onLogin);
}


public onLogin(loginDetails: LoginDetails) {
    console.log(this.onLogin.name + " " + this.socketID);
}

Answer 1

您必须在arrow函数内调用该函数。

socket.on(this.onLogin.name, (data: LoginDetails) => this.onLogin(data));