50个jQuery代码开发技巧

.filter(":not(:has(.selected))") //去掉所有不包含class为.selected的元素

var allItems = $("div.item"); 
var keepList = $("div#container1 div.item"); 
<div>class names: 
$(formToLookAt + " input:checked").each(function() { keepListkeepList = keepList.filter("." + $(this).attr("name")); });
</div>

//jQuery 1.4.* includes support for the has method. This method will find 
//if a an element contains a certain other element class or whatever it is 
//you are looking for and do anything you want to them. 
$("input").has(".email").addClass("email_icon");

//Look for the media-type you wish to switch then set the href to your new style sheet 
$('link[media='screen']').attr('href', 'Alternative.css');

//Where possible, pre-fix your class names with a tag name 
//so that jQuery doesn't have to spend more time searching 
//for the element you're after. Also remember that anything 
//you can do to be more specific about where the element is 
//on your page will cut down on execution/search times 
var in_stock = $('#shopping_cart_items input.is_in_stock');
<ul id="shopping_cart_items"> 
<li> 
<input value="Item-X" name="item" type="radio"> Item X</li> 
<li> 
<input value="Item-Y" name="item" type="radio"> Item Y</li> 
<li> 
<input value="Item-Z" name="item" type="radio"> Item Z</li> 
</ul>

//Toggle class allows you to add or remove a class 
//from an element depending on the presence of that 
//class. Where some developers would use: 
a.hasClass('blueButton') ? a.removeClass('blueButton') : a.addClass('blueButton'); 
//toggleClass allows you to easily do this using 
a.toggleClass('blueButton');

if ($.browser.msie) { // Internet Explorer is a sadist. }

$('#thatdiv').replaceWith('fnuh');

if ($('#keks').html()) { //Nothing found ;}

$("ul > li").click(function () { 
var index = $(this).prevAll().length; 
});

$('#foo').bind('click', function() { 
alert('User clicked on "foo."'); 
});

$('#lal').append('sometext');

var e = $("", { href: "#", class: "a-class another-class", title: "..." });

//This precision-based approached can be useful when you use 
//lots of similar input elements which have different types 
var elements = $('#someid input[type=sometype][value=somevalue]').get();

jQuery.preloadImages = function() { for(var i = 0; i').attr('src', arguments[i]); } }; 
// Usage $.preloadImages('image1.gif', '/path/to/image2.png', 'some/image3.jpg');

$('button.someClass').live('click', someFunction);
//Note that in jQuery 1.4.2, the delegate and undelegate options have been
//introduced to replace live as they offer better support for context
//For example, in terms of a table where before you would use..
// .live()
$("table").each(function(){
$("td", this).live("hover", function(){
$(this).toggleClass("hover");
});
});
//Now use..
$("table").delegate("td", "hover", function(){
$(this).toggleClass("hover");
});

$('#someElement').find('option:selected');

$("p.value:contains('thetextvalue')").hide();

jQuery.fn.autoscroll = function(selector) {
$('html,body').animate(
{scrollTop: $(selector).offset().top},
500
);
}
//Then to scroll to the class/area you wish to get to like this:
$('.area_name').autoscroll();

Detect Safari (if( $.browser.safari)),
Detect IE6 and over (if ($.browser.msie && $.browser.version > 6 )),
Detect IE6 and below (if ($.browser.msie && $.browser.version <= 6 )),
Detect FireFox 2 and above (if ($.browser.mozilla && $.browser.version >= '1.8' ))

var el = $('#id');
el.html(el.html().replace(/word/ig, ''));

$(document).bind('contextmenu',function(e){ return false; });

$.expr[':'].mycustomselector = function(element, index, meta, stack){
// element- is a DOM element
// index - the current loop index in stack
// meta - meta data about your selector
// stack - stack of all elements to loop
// Return true to include current element
// Return false to explude current element
};
// Custom Selector usage:
$('.someClasses:test').doSomething();

if ($('#someDiv').length) {//hooray!!! it exists...}

$("#someelement").live('click', function(e) {
if( (!$.browser.msie && e.button == 0) || ($.browser.msie && e.button == 1) ) {
alert("Left Mouse Button Clicked");
}
else if(e.button == 2)
alert("Right Mouse Button Clicked");
});

//This snippet will show you how to keep a default value
//in a text input field for when a user hasn't entered in
//a value to replace it
swap_val = [];
$(".swap").each(function(i){
swap_val[i] = $(this).val();
$(this).focusin(function(){
if ($(this).val() == swap_val[i]) {
$(this).val("");
}
}).focusout(function(){
if ($.trim($(this).val()) == "") {
$(this).val(swap_val[i]);
}
});
});
<INPUT value="Enter Username here.." type=text>

//Here's how we used to do it in 1.3.2 using setTimeout
setTimeout(function() {
$('.mydiv').hide('blind', {}, 500)
}, 5000);
//And here's how you can do it with 1.4 using the delay() feature (this is a lot like sleep)
$(".mydiv").delay(5000).hide('blind', {}, 500);

var newgbin1Div = $('');
newgbin1Div.attr('id','gbin1.com').appendTo('body');

jQuery.fn.maxLength = function(max){
this.each(function(){
var type = this.tagName.toLowerCase();
var inputType = this.type? this.type.toLowerCase() : null;
if(type == "input" && inputType == "text" || inputType == "password"){
//Apply the standard maxLength
this.maxLength = max;
}
else if(type == "textarea"){
this.onkeypress = function(e){
var ob = e || event;
var keyCode = ob.keyCode;
var hasSelection = document.selection? document.selection.createRange().text.length > 0 : this.selectionStart != this.selectionEnd;
return !(this.value.length >= max && (keyCode > 50 || keyCode == 32 || keyCode == 0 || keyCode == 13) && !ob.ctrlKey && !ob.altKey && !hasSelection);
};
this.onkeyup = function(){
if(this.value.length > max){
this.value = this.value.substring(0,max);
}
};
}
});
};
//Usage:
$('#gbin1textarea').maxLength(500);

//Separate tests into modules.
module("Module B");
test("some other gbin1.com test", function() {
//Specify how many assertions are expected to run within a test.
expect(2);
//A comparison assertion, equivalent to JUnit's assertEquals.
equals( true, false, "failing test" );
equals( true, true, "passing test" );
});

var cloned = $('#gbin1div').clone();

if($(element).is(':visible') == 'true') { //The element is Visible }

jQuery.fn.center = function () {
this.css('position','absolute');
this.css('top', ( $(window).height() - this.height() ) / +$(window).scrollTop() + 'px');
this.css('left', ( $(window).width() - this.width() ) / 2+$(window).scrollLeft() + 'px');return this;
}
//Use the above function as: $('#gbin1div').center();

var arrInputValues = new Array();
$("input[name='table[]']").each(function(){
arrInputValues.push($(this).val());
});

(function($) {
$.fn.stripHtml = function() {
var regexp = /<("[^"]*"|'[^']*'|[^'">])*>/gi;
this.each(function() {
$(this).html(
$(this).html().replace(regexp,"")
);
});
return $(this);
}
})(jQuery);
//usage:
$('p').stripHtml();
36. 使用closest来得到父元素

$('#searchBox').closest('div');

// Allows chainable logging
// Usage: $('#someDiv').hide().log('div hidden').addClass('someClass');
jQuery.log = jQuery.fn.log = function (msg) {
if (console){
console.log("%s: %o", msg, this);
}
return this;
};

jQuery('a.popup').live('click', function(){
newwindow=window.open($(this).attr('href'),'','height=200,width=150');
if (window.focus) {newwindow.focus()}
return false;
});

jQuery('a.newTab').live('click', function(){
newwindow=window.open($(this).href);
jQuery(this).target = "_blank";
return false;
});

// Rather than doing this
$('#nav li').click(function(){
$('#nav li').removeClass('active');
$(this).addClass('active');
});
// Do this instead
$('#nav li').click(function(){
$(this).addClass('active')
.siblings().removeClass('active');
});

var tog = false; // or true if they are checked on load
$('a').click(function() {
$("input[type=checkbox]").attr("checked",!tog);
tog = !tog;
});

//If the value of the element matches that of the entered text
//it will be returned
$('.gbin1Class').filter(function() {
return $(this).attr('value') == $('input#gbin1Id').val() ;
})

$(document).mousemove(function(e){
$(document).ready(function() {
$().mousemove(function(e){
$('#XY').html("Gbin1 X Axis : " + e.pageX + " | Gbin1 Y Axis " + e.pageY);
});
});

$("ul li").click(function(){
window.location=$(this).find("a").attr("href"); return false;
});
<UL>
<LI><A href="#">GBin1 Link 1</A></LI>
<LI><A href="#">GBin1 Link 2</A></LI>
<LI><A href="#">GBin1 Link 3</A></LI>
<LI><A href="#">GBin1 Link 4</A></LI>
</UL>

function parseXml(xml) {
//find every Tutorial and print the author
$(xml).find("Tutorial").each(function()
{
$("#output").append($(this).attr("author") + "");
});
}

$('#theGBin1Image').attr('src', 'image.jpg').load(function() {
alert('This Image Has Been Loaded');
});

//Events can be namespaced like this
$('input').bind('blur.validation', function(e){
// ...
});
//The data method also accept namespaces
$('input').data('validation.isValid', true);

var dt = new Date();
dt.setSeconds(dt.getSeconds() + 60);
document.cookie = "cookietest=1; expires=" + dt.toGMTString();
var cookiesEnabled = document.cookie.indexOf("cookietest=") != -1;
if(!cookiesEnabled)
{
//cookies have not been enabled
}

var date = new Date();
date.setTime(date.getTime() + (x * 60 * 1000));
$.cookie('example', 'foo', { expires: date });

$.fn.replaceUrl = function() {
var regexp = /((ftp|http|https)://(w+:{0,1}w*@)?(S+)(:[0-9]+)?(/|/([w#!:.?+=&%@!-/]))?)/gi;
this.each(function() {
$(this).html(
$(this).html().replace(regexp,'<A href="$1">$1</A>')
);
});
return $(this);
}
//usage
$('#GBin1div').replaceUrl();