ZoneEventDelegate

event-delegate.js

class EventDelegate {

    constructor() {
        this.events = {};
        window.eventDelegate = this;
    }

    addEvent(newEvent, eventSelector, handle) {
        this.createEvent(newEvent);

        if (!this.events[newEvent][eventSelector]) {
            this.events[newEvent][eventSelector] = [];
        }
        if (this.events[newEvent][eventSelector].indexOf(handle) < 0) {
            this.events[newEvent][eventSelector].push(handle);
        }
    }

    debugInfo() {
        console.log(this.events);
    }

    createEvent(event) {
        if (!this.events[event]) {
            this.events[event] = {};
            this.bindEvent(event);
        }
    }

    bindEvent(event) {
        document.addEventListener(event, this.eventBubbling.bind(this));
    }

    selectorMatches(el, selector) {
        //use prototype for matches
        var p = Element.prototype;
        var f = p.matches || p.webkitMatchesSelector || p.mozMatchesSelector || p.msMatchesSelector || function (s) {
            return Array.prototype.indexOf.call(document.querySelectorAll(s), this) !== -1;
        };
        return f.call(el, selector);
    }

    eventBubbling(event) {
        let type = event.type;

        if (!this.events[type]) {
            return;
        }

        for (let elem = event.target; elem && elem !== document.body; elem = elem.parentNode) {
            for (let selector in this.events[type]) {
                if (this.selectorMatches(elem, selector)) {
                    this.runHandle(type, elem, selector, event);
                }
            }
        };
    }

    runHandle(type, elem, selector, event) {
        this.events[type][selector].map((handle)=>{
            handle.call(elem, event);
        });
    }
}

export default EventDelegate;