mass种子模块之domready

总结：由于IE6/7/8不支持DOMContentLoaded事件，虽然它支持onreadystatechange事件，但是readyState=complete几乎和onload事件一样，需要等页面中的外部资源加载完后才触发，想要尽快可采用doScroll检测法（仅在非iframe下有效）

 1 var turbo = turbo || {};
 2 var W3C = document.addEventListener ? true : false;
 3 var doc = document, html = document.documentElement;
 4 var readyList = [];
 5 turbo.ready = function(fn) {
 6     //不管是哪个分支，只要触发过一次ready事件readyList就会为null
 7     if (readyList) {
 8         readyList.push(fn);
 9     } else {
10         fn();
11     }
12 };
13 function fireReady() {
14     if (readyList && readyList.length) {
15         for (var i = 0, len = readyList.length; i < len; i++) {
16             var fn = readyList[i];
17             fn();
18         }
19     }
20     readyList = null;
21 }
22
23 function doScrollCheck() {
24     try {
25         html.doScroll(‘left‘);
26         fireReady();
27     } catch (e) {
28         setTimeout(doScrollCheck, 50);
29     }
30 }
31
32 var ready = W3C ? "DOMContentLoaded" : "readystatechange";
33 //由于firefox3.6不支持readyState，则在不支持readyState的时需手动赋值给它
34 if (!doc.readyState) {
35     //如果doc.body已存在则说明domcontentloaded了，将doc.readySate设置为complete
36     var readyState = doc.readySate = doc.body ? "complete" : "loading";
37 }
38
39 if (doc.readyState == ‘complete‘) {
40     fireReady();
41 } else {
42     $.bind(doc, ready, function() {
43         if (W3C || doc.readyState == ‘complete‘) {
44             fireReady();
45             //firefox3.6,我觉得这里设不设置都行，因为这里已经用不到了doc.readyState了
46             if (readyState) {
47                 doc.readyState = ‘complete‘;
48             }
49         }
50     })
51     //ie下使用doScroll，尽量提前触发ready，此方法只在非iframe下的页面有效
52     var top = false;
53     try {
54         top = doc.frameElement == null && doc.documentElement;
55     } catch (e) {}
56     if (top && top.doScroll) {
57         doScrollCheck();
58     }
59 }

有点看不懂mass里最后一段调用doScrollCheck的代码，故采用的jQuery的写法.

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