Question

如何将EventEmitter子类化？我正在尝试以下测试：

 var util = require('util')
   ,events = require('events');

function Downloader() {

    events.EventEmitter.call(this);
}
util.inherits(Downloader, events.EventEmitter);
console.log(new Downloader() instanceof events.EventEmitter); // true
Downloader.prototype.download = function(episode) {
    var self = this;

    var statusMessage = 'Downloading: ' + episode;
    self.emit('status', statusMessage);    

    setTimeout(function() {
        var finishedMessage = 'Downloaded ' + episode;
        self.emit('finished', finishedMessage);
    }, 5000);    
}

exports.Downloader = new Downloader();

节点抱怨'对象'没有方法'打开'。但是当检查Downloader instanceOf EventEmitter时返回true。

有人可以解释一下吗？谢谢！

Answer 1

哦，天哪。首先它应该是'module.exports'。其次它的'instanceof'不是'instanceOf'。

我的坏。这是一个有效的例子

var util = require('util')
   ,events = require('events');

function Downloader() {

    events.EventEmitter.call(this);
}
util.inherits(Downloader, events.EventEmitter);

Downloader.prototype.download = function(episode) {
    var self = this;

    var statusMessage = 'Downloading: ' + episode;
    self.emit('status', statusMessage);    

    setTimeout(function() {
        var finishedMessage = 'Downloaded ' + episode;
        self.emit('finished', finishedMessage);
    }, 5000);    
}

module.exports = new Downloader();

子类化events.EventEmitter不起作用

1 个答案: