60個很實用的jQuery代碼開發技巧收集，jquery開發技巧

60個很實用的jQuery代碼開發技巧收集，jquery開發技巧

由於內容比較多建議用CTRL+F搜尋

偶然在網上看到這些不錯的jQuery代碼開發技巧。原文收集了30個，另外尋找的時候發現了還有20個。加上另外十個實用的jQuery程式碼片段，共60個代碼技巧，收集在一起分享給大家。

1. 建立一個嵌套的過濾器

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

2. 重用你的元素查詢

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>

3. 使用has()來判斷一個元素是否包含特定的class或者元素

//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");

4. 使用jQuery轉場樣式

//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'); 

5. 限制選擇的地區

//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" class="is_in_stock" type="radio"> Item X</li> <li> <input value="Item-Y" name="item" class="3-5_days" type="radio"> Item Y</li> <li> <input value="Item-Z" name="item" class="unknown" type="radio"> Item Z</li> </ul> 

6. 如何正確使用ToggleClass

//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'); 

7. 設定IE指定的功能

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

8. 使用jQuery來替換一個元素

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

9. 驗證一個元素是否為空白

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

10. 在無序的set中尋找一個元素的索引

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

11. 綁定一個函數到一個事件

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

12. 添加HTML到一個元素

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

13. 建立元素時使用對象來定義屬性

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

14. 使用過濾器過濾多屬性

//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(); 

15. 使用jQuery預先載入圖片

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

16. 設定任何匹配一個選取器的事件處理常式

$('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");});

17. 找到被選擇到的選項(option)元素

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

18. 隱藏包含特定值的元素

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

19. 自動的滾動到頁面特定地區

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();

20. 檢測各種瀏覽器

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' ))

21. 替換字串中的單詞

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

22. 關閉右鍵的菜單

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

23. 定義一個定製的選取器

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

24. 判斷一個元素是否存在

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

25. 使用jQuery判斷滑鼠的左右鍵點擊

$("#someelement").live('click', function(e) { if( (!$.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");});

26. 顯示或者刪除輸入框的預設值

//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 itswap_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 class=swap value="Enter Username here.." type=text> 

27. 指定時間後自動隱藏或者關閉元素(1.4支援）

//Here's how we used to do it in 1.3.2 using setTimeoutsetTimeout(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);

28. 動態建立元素到DOM

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

29. 限制textarea的字元數量

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);

30. 為函數建立一個基本測試案例

//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" );});

31. 使用jQuery複製元素

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

32. 測試一個元素在jQuery中是否可見

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

33. 元素螢幕置中

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();

34. 使用特定名字的元素對應的值產生一個數組

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

35. 剔除元素中的HTML

(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來得到父元素

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

37. 使用firebug來記錄jQuery事件

// 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;};

38. 點選連結強制彈出新視窗

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

39. 點選連結強制開啟新標籤頁

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

40. 使用siblings()來處理同類元素

// 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');});

41. 選擇或者不選頁面上全部複選框

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

42. 基於輸入文字過濾頁面元素

//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() ; })

43. 取得滑鼠的X和Y座標

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

44. 使得整個列表元素(LI)可點擊

$("ul li").click(function(){ window.location=$(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> 

45. 使用jQuery來解析XML

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

46. 判斷一個圖片是否載入完全

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

47. 使用jQuery命名事件

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

48. 判斷cookie是否啟用或者關閉

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}

49. 強制到期cookie

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

50. 使用一個可點擊的連結替換頁面中所有URL

$.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(); 

51: 在表單中禁用“斷行符號鍵”

大家可能在表單的操作中需要防止使用者意外的提交表單，那麼下面這段代碼肯定非常有協助：

$("#form").keypress(function(e) { if (e.which == 13) { return false; }});

52: 清除所有的表單資料

可能針對不同的表單形式，你需要調用不同類型的清楚方法，不過使用下面這個現成方法，絕對能讓你省不少功夫。

function clearForm(form) { // iterate over all of the inputs for the form // element that was passed in $(':input', form).each(function() { var type = this.type; var tag = this.tagName.toLowerCase(); // normalize case // it's ok to reset the value attr of text inputs, // password inputs, and textareas if (type == 'text' || type == 'password' || tag == 'textarea')  this.value = ""; // checkboxes and radios need to have their checked state cleared // but should *not* have their 'value' changed else if (type == 'checkbox' || type == 'radio')  this.checked = false; // select elements need to have their 'selectedIndex' property set to -1 // (this works for both single and multiple select elements) else if (tag == 'select')  this.selectedIndex = -1; });};

53: 將表單中的按鈕禁用

下面的代碼對於ajax操作非常有用，你可以有效避免使用者多次提交資料，個人也經常使用：

禁用按鈕：

$("#somebutton").attr("disabled", true);

啟動按鈕：

$("#submit-button").removeAttr("disabled");

可能大家往往會使用.attr(‘disabled',false);，不過這是不正確的調用。

54: 輸入內容後啟用遞交按鈕

這個代碼和上面類似，都屬於協助使用者控製表單遞交按鈕。使用這段代碼後，遞交按鈕只有在使用者輸入指定內容後才可以啟動。

$('#username').keyup(function() { $('#submit').attr('disabled', !$('#username').val()); });

55: 禁止多次遞交表單

多次遞交表單對於web應用來說是個比較頭疼的問題，下面的代碼能夠很好的協助你解決這個問題：

$(document).ready(function() { $('form').submit(function() { if(typeof jQuery.data(this, "disabledOnSubmit") == 'undefined') {  jQuery.data(this, "disabledOnSubmit", { submited: true });  $('input[type=submit], input[type=button]', this).each(function() {  $(this).attr("disabled", "disabled");  });  return true; } else {  return false; } });});

56: 高亮顯示目前聚焦的輸入框標示

有時候你需要提示使用者目前操作的輸入框，你可以使用下面代碼高亮顯示標示：

$("form :input").focus(function() { $("label[for='" + this.id + "']").addClass("labelfocus");}).blur(function() { $("label").removeClass("labelfocus");});

57: 動態方式添加表單元素

這個方法可以協助你動態添加表單中的元素，比如，input等：

//change event on password1 field to prompt new input$('#password1').change(function() {  //dynamically create new input and insert after password1  $("#password1").append("<input type='text' name='password2' id='password2' />");});

58: 自動將資料匯入selectbox中

下面代碼能夠使用ajax資料自動產生選擇框的內容

$(function(){ $("select#ctlJob").change(function(){ $.getJSON("/select.php",{id: $(this).val(), ajax: 'true'}, function(j){  var options = '';  for (var i = 0; i < j.length; i++) {  options += '<option value="' + j[i].optionValue + '">' + j[i].optionDisplay + '</option>';  }  $("select#ctlPerson").html(options); }) })})

59: 判斷一個複選框是否被選中

代碼很簡單，如下：

$('#checkBox').attr('checked');

60: 使用代碼來遞交表單

代碼很簡單，如下：

$("#myform").submit();