Cache js,css to localStorage

(function(arr, cache) {

	var wl = window.localStorage;

	var insert = function(fileContent, elem) {
		var el = document.createElement(elem);
		el.innerHTML = fileContent;
		document.querySelector('head').appendChild(el);
	};

	var _downloadFile = function(path) {
		var xhr = new XMLHttpRequest();

		xhr.open('GET', path, false);
		xhr.send(null);

		if (xhr.status == 200) {
			return xhr.responseText
		}
	}

	arr.forEach(function(obj) {

		var data = wl.getItem(obj.path);

		if (!data) {
			data = _downloadFile(obj.path);

			if (cache)
				wl.setItem(obj.path, data);
		}

		insert(data, obj.tag);

	})

})([
	{ tag: "style",  path: "css/main.css" },
	{ tag: "script", path: "js/main.js" }
], false)