javascript - 如何在 Javascript 中为非 dom 元素添加事件监听器？

Question

在 Java、C#、Actionscript 等中。事件是针对类的，而在 Javascript 中，它似乎仅限于 dom。我在这里读了一个用 jQuery 做的例子 http://www.west-wind.com/weblog/posts/2010/May/27/NonDom-Element-Event-Binding-with-jQuery

但是如果我不需要 jQuery 并且我想了解该机制，您会怎么做？

Answer 1

最简单的机制是这样的:

function PubSub() {
    this.subs = {};
    this.subscribe = function(channel, sub) {
        this.subs[channel] = this.subs[channel] || []; //create array for channel
        this.subs[channel].push(sub);
    };
    this.publish = function(channel) {
        var args = [].slice.call(arguments, 1); //pop off channel argument
        this.subs[channel].forEach(function(sub) {
            sub.apply(void 0, args); //call each method listening on the channel
        });
    };
}

此处演示:http://jsfiddle.net/3PNtR/

-- 编辑(~5 年后)--

同样简单的机制，更新的语法

class PubSub {
    constructor () {
        this.subs = {}
    }
    subscribe (channel, sub) {
        this.subs[channel] = this.subs[channel] || []
        this.subs[channel].push(sub)
    }
    publish (channel, ...args) {
        ;(this.subs[channel] || []).forEach(sub => sub(...args))
    }
}