(function(win){
'use strict'; var listeners = [];
var doc = win.document;
var MutationObserver = win.MutationObserver || win.WebKitMutationObserver;
var observer; function ready(selector, fn){
// 储存选择器和回调函数
listeners.push({
selector: selector,
fn: fn
});
if(!observer){
// 监听document变化
observer = new MutationObserver(check);
observer.observe(doc.documentElement, {
childList: true,
subtree: true
});
}
// 检查该节点是否已经在DOM中
check();
} function check(){
// 检查是否匹配已储存的节点
for(var i = 0; i < listeners.length; i++){
var listener = listeners[i];
// 检查指定节点是否有匹配
var elements = doc.querySelectorAll(listener.selector);
for(var j = 0; j < elements.length; j++){
var element = elements[j];
// 确保回调函数只会对该元素调用一次
if(!element.ready){
element.ready = true;
// 对该节点调用回调函数
listener.fn.call(element, element);
}
}
}
} // 对外暴露ready
win.ready = ready;})(this);ready('.foo', function(element){
// ...
});
当任何元素生成都会触发回调函数check