资源加载器
var load = (function() {
function _load(tag) {
return function(url) {
return new Promise(function(resolve, reject) {
var element = document.createElement(tag);
var parent = 'body';
var attr = 'src';
element.onload = function() {
resolve(url);
};
element.onerror = function() {
reject(url);
};
switch(tag) {
case 'script':
element.async = true;
break;
case 'link':
element.type = 'text/css';
element.rel = 'stylesheet';
attr = 'href';
parent = 'head';
}
element[attr] = url;
document[parent].appendChild(element);
});
};
}
return {
css: _load('link'),
js: _load('script'),
img: _load('img')
}
})();
Promise.all([
load.js('lib/highlighter.js'),
load.js('lib/main.js'),
load.css('lib/highlighter.css'),
load.img('images/logo.png')
]).then(function() {
console.log('Everything has loaded!');
}).catch(function() {
console.log('Oh no, epic failure!');
});
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