很多的 JavaScript 开发人员,包括我在内,都很喜欢 jQuery。因为它的简单,因为它有很多丰富的插件可供使用,和其它优秀的工具一样,jQuery 让我们开发人员能够更轻松的开发网站和 Web 应用。
然而,另一方面,作为前端开发的基础框架,jQuery 包含大量的兼容性代码和扩展功能,其中有很多在你的整个项目中可能都不会用到。其实如果你只是针对现代浏览器,很多功能使用原生的 JavaScript 就可以实现,即使是拖后腿的低版本 IE 浏览器,兼容性也是很容易处理的。
本文出处【http://www.cnblogs.com/lhb25/】
下面就带大家一起看看在 IE 浏览器环境中如果使用原生 JavaScript 代码实现 jQuery 中的功能。如果你打算自己开发一个小的基础框架,可以好好参考一下这些代码的实现。
Ajax Post
jQuery:
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$.ajax({ type: ‘POST‘ ,
url: ‘/my/url‘ ,
data: data
}); |
IE8+:
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var
request = new
XMLHttpRequest();
request.open( ‘POST‘ , ‘/my/url‘ , true );
request.send(data); |
Ajax Get
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$.ajax({ type: ‘GET‘ ,
url: ‘/my/url‘ ,
success: function (resp) {
},
error: function () {
}
}); |
IE8+:
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request = new
XMLHttpRequest();
request.open( ‘GET‘ , ‘/my/url‘ , true );
request.onreadystatechange = function () {
if
( this .readyState === 4){
if
( this .status >= 200 && this .status < 400){
// Success!
resp = this .responseText;
} else
{
// Error :(
}
}
} request.send(); request = null ;
|
加载 JSON
jQuery:
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$.getJSON( ‘/my/url‘ , function (data) {
}); |
IE8+:
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request = new
XMLHttpRequest();
request.open( ‘GET‘ , ‘/my/url‘ , true );
request.onreadystatechange = function () {
if
( this .readyState === 4){
if
( this .status >= 200 && this .status < 400){
// Success!
data = JSON.parse( this .responseText);
} else
{
// Error :(
}
}
} request.send(); request = null ;
|
淡入效果
jQuery:
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$(el).fadeIn(); |
IE8+:
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function
fadeIn(el) {
var
opacity = 0;
el.style.opacity = 0;
el.style.filter = ‘‘ ;
var
last = + new
Date();
var
tick = function () {
opacity += ( new
Date() - last) / 400;
el.style.opacity = opacity;
el.style.filter = ‘alpha(opacity=‘
+ (100 * opacity)|0 + ‘)‘ ;
last = + new
Date();
if
(opacity < 1) {
(window.requestAnimationFrame && requestAnimationFrame(tick)) || setTimeout(tick, 16);
}
};
tick();
} fadeIn(el); |
显示和隐藏
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$(el).show(); $(el).hide(); |
IE8+:
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el.style.display = ‘‘ ;
el.style.display = ‘none‘ ;
|
添加 Class
jQuery:
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$(el).addClass(className); |
IE8+:
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if
(el.classList)
el.classList.add(className);
else el.className += ‘ ‘
+ className;
|
插入 HTML
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$(el).before(htmlString); $(parent).append(el); $(el).after(htmlString); |
IE8+:
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el.insertAdjacentHTML( ‘beforebegin‘ , htmlString);
parent.appendChild(el); el.insertAdjacentHTML( ‘afterend‘ , htmlString);
|
获取子节点
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$(el).children(); |
IE8+:
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var
children = [];
for
( var
i=el.children.length; i--;){
// Skip comment nodes on IE8
if
(el.children[i].nodeType != 8)
children.unshift(el.children[i]);
} |
循环节点
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$(selector).each( function (i, el){
}); |
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function
forEachElement(selector, fn) {
var
elements = document.querySelectorAll(selector);
for
( var
i = 0; i < elements.length; i++)
fn(elements[i], i);
} forEachElement(selector, function (el, i){
}); |
清空节点
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$(el).empty(); |
IE8+:
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while (el.firstChild)
el.removeChild(el.firstChild)
|
过滤节点
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$(selector).filter(filterFn); |
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function
filter(selector, filterFn) {
var
elements = document.querySelectorAll(selector);
var
out = [];
for
( var
i = elements.length; i--;) {
if
(filterFn(elements[i]))
out.unshift(elements[i]);
}
return
out;
} filter(selector, filterFn); |
查找元素
jQuery:
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$(el).find(selector); $( ‘.my #awesome selector‘ );
|
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el.querySelectorAll(selector); document.querySelectorAll( ‘.my #awesome selector‘ );
|
获取属性、HTML或者文本
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$(el).attr( ‘tabindex‘ );
$(el).html(); $( ‘<div>‘ ).append($(el).clone()).html();
$(el).text(); |
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el.getAttribute( ‘tabindex‘ );
el.innerHTML el.outerHTML el.textContent || el.innerText |
判断是否包含某个 css class
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$(el).hasClass(className); |
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if
(el.classList)
el.classList.contains(className);
else new
RegExp( ‘(^| )‘
+ className + ‘( |$)‘ , ‘gi‘ ).test(el.className);
|
选择器匹配
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$(el).is( ‘.my-class‘ );
|
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var
matches = function (el, selector) {
var
_matches = (el.matches || el.matchesSelector || el.msMatchesSelector || el.mozMatchesSelector || el.webkitMatchesSelector || el.oMatchesSelector);
if
(_matches) {
return
_matches.call(el, selector);
} else
{
var
nodes = el.parentNode.querySelectorAll(selector);
for
( var
i = nodes.length; i--;)
if
(nodes[i] === el) {
return
true ;
}
return
false ;
} matches(el, ‘.my-class‘ );
|
前一个节点
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$(el).prev(); |
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// prevSibling can include text nodes function
previousElementSibling(el) {
do
{ el = el.previousSibling; } while
( el && el.nodeType !== 1 );
return
el;
} el.previousElementSibling || previousElementSibling(el); |
后一个节点
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$(el).next(); |
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// nextSibling can include text nodes function
nextElementSibling(el) {
do
{ el = el.nextSibling; } while
( el && el.nodeType !== 1 );
return
el;
} el.nextElementSibling || nextElementSibling(el); |
外部高度
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$(el).outerHeight() |
IE8+:
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function
outerHeight(el, includeMargin){
var
height = el.offsetHeight;
if (includeMargin){
var
style = el.currentStyle || getComputedStyle(el);
height += parseInt(style.marginTop) + parseInt(style.marginBottom);
}
return
height;
} outerHeight(el, true );
|
外部宽度
jQuery:
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$(el).outerWidth() |
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function
outerWidth(el, includeMargin){
var
height = el.offsetWidth;
if (includeMargin){
var
style = el.currentStyle || getComputedStyle(el);
height += parseInt(style.marginLeft) + parseInt(style.marginRight);
}
return
height;
} outerWidth(el, true );
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判断是否数组
jQuery:
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$.isArray(arr); |
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isArray = Array.isArray || function (arr) {
return
Object.prototype.toString.call(arr) == ‘[object Array]‘ ;
} isArray(arr); |
数组转换
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$.map(array, function (value, index){
}) |
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function
map(arr, fn) {
var
results = []
for
( var
i = 0; i < arr.length; i++)
results.push(fn(arr[i], i))
return
results
} map(array, function (value, index){
}) |
类似的还有很多很多,可以参考这里:http://youmightnotneedjquery.com/
本文链接:你可能不需要 jQuery!编写原生的JavaScript代码