30个经典的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 usinga.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');

　　16. 设置任何匹配一个选择器的事件处理程序

　　[code]$('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" );

　　});