helper.js

var css3s = ['transform', 'transition'];

export default{
    offset(element){
        var top = 0, left = 0;

        do{
            top += element.offsetTop;
            left += element.offsetLeft;
        }while(element = element.offsetParent);

        return {
            left,
            top
        }
    },

    siblings(element){
        return [].filter.call(element.parentNode.children, (child) => child !== element);
    },

    height(element){
        return this.isDoc(element) ? document.documentElement.clientHeight : element.offsetHeight;
    },

    width(element){
        return this.isDoc(element) ? document.documentElement.clientWidth : element.offsetWidth;
    },

    size(element){
        return {width: this.width(element), height: this.height(element)};
    },

    rect(element){
        return element.getBoundingClientRect();
    },

    isDoc(element){
        return element === document.documentElement || element === document;
    },

    contains(root, el){
        return root === el || !!(root.compareDocumentPosition(el) & 16); 
    },

    on(element, event, callback){
        element.addEventListener(event, callback);
    },

    off(element, event, callback){
        element.removeEventListener(event, callback);
    },

    trigger(element, event, data = []){
        var evt = document.createEvent('HTMLEvents');
        evt.initEvent(event, true, true);
        evt.data = data;
        return !element.dispatchEvent(evt);
    },

    l2camel(str){
        return str.replace(/-(\w)/g, (all, c, index) => index > 0 ? c.toUpperCase() : c);
    },

    css(element, name, value){
        if(typeof name == 'object'){
            for(var key in name){
                this.css(element, key, name[key]);
            }
        }else{
            var css3name;

            if(this.css3(name)){
                css3name = this.l2camel('-webkit-' + name);
            }

            name = this.l2camel(name);

            if(typeof value == 'undefined'){
                return element.style[css3name || name] || window.getComputedStyle(element).getPropertyValue(css3name || name);
            }else{
                value += (typeof value == 'number' && !/^(?:opacity|zIndex)$/.test(name) ? 'px' : '');
                element.style[name] = value;

                if(css3name){
                    element.style[css3name] = value; 
                }
            }
        }
    },

    css3(name){
        return css3s.indexOf(name) > -1;
    },

    assign(obj){
        [].slice.call(arguments, 1).forEach((args) => {
            for(var i in args){
                obj[i] = args[i];
            }
        })

        return obj
    },

    $(str, root = document){
        return typeof str == 'string' ? root.querySelector(str) : str;
    },

    $$(str, root = document){
        return (typeof str == 'string' ? root.querySelectorAll(str) : str) || [];
    },

    each(arr, callback){
        if(arr.length){
            [].forEach.call(arr, callback);
        }else{
            for(var i in arr){
                callback(arr[i], i);
            }
        }
    },

    hasClass(element, className){  
        return element.className.match(new RegExp('(\\s+|^)' + className + '(\\s+|$)'));  
    },

    addClass(element, className){
        if(this.hasClass(element, className)){
            element.className += ' ' + className;
        }
    },

    removeClass(element, className){
        element.className = element.className.replace(new RegExp('(\\s+|^)' + className + '(\\s+|$)'));
    },

    rfa(callback){
        return (window.requestAnimationFrame     ||
            window.webkitRequestAnimationFrame  ||
            function (callback) { window.setTimeout(callback, 1000 / 60); })(callback);
    },

    crfa(id){
        return id && (
            window.cancelRequestAnimationFrame ||
            window.webkitCancelAnimationFrame  ||
            window.clearTimeout
        )(id);
    },

    makeArray(arr){
        if(Array.isArray(arr)){
            return arr;
        }

        return arr == null ? [] : [arr];
    },

    log(){
        var str = JSON.stringify(arguments);
        var container = document.querySelector('#__log__');

        if(!container){
            container = document.createElement('div');
            container.style.cssText = 'position: fixed; bottom: 0px; width: 100%; background: #ccc;';
            document.body.appendChild(container);
        }

        container.innerHTML = container.innerHTML + '<br />' + str;
    },

    firstKey(obj){
        for(var i in obj){
            return i;
        }

        return false;
    }
}

!Object.assign && (Object.assign = exports.default.assign);