由于某些原因，我们将从我们的旧版应用程序中删除 jquery(请不要问为什么!)
但是，有 1000 多个由设计师设计的模板文件，正在使用 jquery 就绪功能。我们计划制定以下模拟策略。
<head>
<script type="text/javascript">
// // http://stackoverflow.com/a/9899701
(function(funcName, baseObj) {
// The public function name defaults to window.docReady
// but you can pass in your own object and own function name and those will be used
// if you want to put them in a different namespace
funcName = funcName || "docReady";
baseObj = baseObj || window;
var readyList = [];
var readyFired = false;
var readyEventHandlersInstalled = false;
// call this when the document is ready
// this function protects itself against being called more than once
function ready() {
if (!readyFired) {
// this must be set to true before we start calling callbacks
readyFired = true;
for (var i = 0; i < readyList.length; i++) {
// if a callback here happens to add new ready handlers,
// the docReady() function will see that it already fired
// and will schedule the callback to run right after
// this event loop finishes so all handlers will still execute
// in order and no new ones will be added to the readyList
// while we are processing the list
readyList[i].fn.call(window, readyList[i].ctx);
}
// allow any closures held by these functions to free
readyList = [];
}
}
function readyStateChange() {
if (document.readyState === "complete") {
ready();
}
}
// This is the one public interface
// docReady(fn, context);
// the context argument is optional - if present, it will be passed
// as an argument to the callback
baseObj[funcName] = function(callback, context) {
// if ready has already fired, then just schedule the callback
// to fire asynchronously, but right away
if (readyFired) {
setTimeout(function() {
callback(context);
}, 1);
return;
} else {
// add the function and context to the list
readyList.push({
fn: callback,
ctx: context
});
}
// if document already ready to go, schedule the ready function to run
if (document.readyState === "complete") {
setTimeout(ready, 1);
} else if (!readyEventHandlersInstalled) {
// otherwise if we don't have event handlers installed, install them
if (document.addEventListener) {
// first choice is DOMContentLoaded event
document.addEventListener("DOMContentLoaded", ready, false);
// backup is window load event
window.addEventListener("load", ready, false);
} else {
// must be IE
document.attachEvent("onreadystatechange", readyStateChange);
window.attachEvent("onload", ready);
}
readyEventHandlersInstalled = true;
}
}
})("docReady", window);
// Mock jquery.
var jQuery = function(baseObj) {
return {
ready: function(baseObj) {
docReady(baseObj);
}
}
};
var $ = jQuery;
</script>
</head>
请注意，我们倾向于使用以下代码片段来模拟 jquery。
// Mock jquery.
var jQuery = function (baseObj) {
return {
ready: function (baseObj) {
docReady(baseObj);
}
}
};
var $ = jQuery;
它适用于案例
jQuery(document).ready(function() {...});$(document).ready(function() {...});
但是，我们怎样才能让下面的语法也能工作呢？
$(function() {...});
最佳答案
检查传入的参数是否为函数
var jQuery = function(baseObj) {
if (typeof baseObj === 'function')
return docReady(baseObj);
代码:
// Mock jquery.
var jQuery = function (baseObj) {
if (typeof baseObj === 'function')
return docReady(baseObj);
return {
ready: function (baseObj) {
docReady(baseObj);
}
}
};
var $ = jQuery;
关于javascript - 如何模拟 jquery 就绪函数，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33624881/