使用Express框架的Node.js中的自定义事件 [英] Custom Events in Node.js with Express framework

问题描述

因此，我想知道如何在node.js中创建自定义事件，而我正在碰壁.我很确定我误解了Express的工作原理和node.js事件的工作原理.

So, I'd like to know how to create custom events in node.js, and I'm hitting a wall. I'm pretty sure I'm misunderstanding something about how express works and how node.js events work.

https://creativespace.nodejitsu.com 这就是应用程序.

当用户创建新的活动"(将会发生多次)时，他们会发送POST请求.然后在我的路由中，如果该POST成功，我想发出一个事件，该事件告诉socket.io为该活动创建一个新的命名空间.

When a user creates a new "activity" (something that will happen many times) they send a POST request. Then within my route, if that POST succeeds I'd like to emit an event, that tells socket.io to create a new namespace for that activity.

在我的路线文件中:

var eventEmitter = require('events').EventEmitter;    
// Tell socket.io about the new space.
eventEmitter.emit('new activity', {activityId: body.id});

和socket.io:

And socket.io:

// When someone creates a new activity
eventEmitter.on('new activity', function (data) {  // this gives and error
  var newActivity = '/activity?' + data.activityId;
  io.of(newActivity).on('connection', function (socket) {

    // Socket.io code for an activity

  });
});

所以我得到的错误是无法调用未定义的方法，它指的是上面socket.io中的第2行.我想我正在弄乱我的要求，也许...或者我不太了解事件的工作原理.

So the error I get is CANNOT CALL METHOD ON OF UNDEFINED and it refers to what would be line 2 in the socket.io above. I think I'm messing up my requires, maybe...or I'm not quite understanding how events work.

任何帮助，甚至包括对Node.js事件的良好阅读的参考，都会动摇！

Any help, even a reference to good reading on Node.js events would rock!

谢谢！

推荐答案

您应该将EventEmitter视为可以继承的类.试试这个:

You should treat EventEmitter as a class you can inherit from. Try this:

function MyEmitter () {
  events.EventEmitter.call(this);
}

util.inherits(MyEmitter, events.EventEmitter);

现在您可以使用您的课程来监听和发出事件:

Now you can use your class to listen and emit events:

var e = new MyEmitter;
e.on("test", function (m) { console.log(m); });
e.emit("test", "Hello World!");

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