javascript事件分發模塊

 EventDispatcher.js

function EventDispatcher() {}

Object.assign(EventDispatcher.prototype, {

    addEventListener: function(type, listener) {

        if (this._listeners === undefined) this._listeners = {};

        var listeners = this._listeners;

        if (listeners[type] === undefined) {

            listeners[type] = [];

        }

        if (listeners[type].indexOf(listener) === -1) {

            listeners[type].push(listener);

        }

    },

    hasEventListener: function(type, listener) {

        if (this._listeners === undefined) return false;

        var listeners = this._listeners;

        return listeners[type] !== undefined && listeners[type].indexOf(listener) !== -1;

    },

    removeEventListener: function(type, listener) {

        if (this._listeners === undefined) return;

        var listeners = this._listeners;
        var listenerArray = listeners[type];

        if (listenerArray !== undefined) {

            var index = listenerArray.indexOf(listener);

            if (index !== -1) {

                listenerArray.splice(index, 1);

            }

        }

    },

    dispatchEvent: function(event) {
        if (this._listeners === undefined) return;

        var listeners = this._listeners;
        var listenerArray = listeners[event.type];

        if (listenerArray !== undefined) {

            // event.target = this;

            var array = listenerArray.slice(0);

            for (var i = 0, l = array.length; i < l; i++) {

                array[i].call(this, event);

            }

        }

    }

});


export { EventDispatcher };

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import { EventDispatcher } from "./js/EventDispatcher.js"


let fenFaQi = new EventDispatcher();
fenFaQi.addEventListener("sun", function(obj) {
    console.log("first :" + JSON.stringify(obj.target));
})
fenFaQi.addEventListener("sun", function(obj) {
    console.log("second :" + obj.target);
})

fenFaQi.dispatchEvent({ type: "sun", target: "xu hai tao hunk xu" });
fenFaQi.dispatchEvent({ type: "sun", target: "very good" })

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FR：徐海濤（hunk Xu)
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