18 great jQuery snippets

1. Smooth scrolling of internal links implemented by jQuery
You don't need to use a complex plug-in, just download this code to achieve smooth scrolling based on internal links

$('a[href^="#"]').bind('click.smoothscroll',function (e) {
e.preventDefault();
 
var anchor = this.hash,
$target = $(target);
 
$('html, body').stop().animate({
'scrollTop': $target.offset().top
}, 500, 'swing', function () {
window.location.hash = anchor;
});
 
});

2. Use jQuery to get all nodes

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

3. Limit the number of selection boxes

$("#categories option").click(function(e){
 if ($(this).parent().val().length < 2) {
  $(this).removeAttr("selected");
 }
});

4. jQuery USES wildcards to delete class

var _c = 'your-icon-class'
 
$('.currency').removeClass (function (index, css) {
 return (css.match (/\bicon-\S+/g) || []).join(' ');
}).addClass('icon-'+_c);

5. Toggle enabled and disabled

/* HTML
|
|
<input type="text" value=" Welcome to visit www.admin10000.com" /><input type="button" value=" Disable the button " />
|
|
*/
 
// Plugin
(function ($) {
 $.fn.toggleDisabled = function () {
  return this.each(function () {
   var $this = $(this);
   if ($this.attr('disabled')) $this.removeAttr('disabled');
   else $this.attr('disabled', 'disabled');
  });
 };
})(jQuery);
 
// TEST
$(function () {
 $('input:button').click(function () {
  $('input:text').toggleDisabled();
 });
});

Smooth scrolling back to the top

<h1 id="anchor">admin10000.com</h1>
<a class="topLink" href="#anchor"> Return to the top </a>
 
$(document).ready(function () {
 
 $("a.topLink").click(function () {
  $("html, body").animate({
   scrollTop: $($(this).attr("href")).offset().top + "px"
  }, {
   duration: 500,
   easing: "swing"
  });
  return false;
 });
 
});

7. Use jQuery and Google Analytics to track forms

var array1 = [];
$(document).ready(function () {
 $('input').change(function () {
  var formbox = $(this).attr('id');
  array1.push(formbox);
  console.log("you filled out box " + array1);
 });
 $('#submit').click(function () {
  console.log('tracked ' + array1);
  //alert('this is the order of boxes you filled out: ' + array1);
  _gaq.push(['_trackEvent', 'Form', 'completed', '"' + array1 + '"']);
 });
});

8, super simple password strength tips

$('#pass').keyup(function (e) {
 var strongRegex = new RegExp("^(?=.{8,})(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])(?=.*\W).*$", "g");
 var mediumRegex = new RegExp("^(?=.{7,})(((?=.*[A-Z])(?=.*[a-z]))|((?=.*[A-Z])(?=.*[0-9]))|((?=.*[a-z])(?=.*[0-9]))).*$", "g");
 var enoughRegex = new RegExp("(?=.{6,}).*", "g");
 if (false == enoughRegex.test($(this).val())) {
  $('#passstrength').html('More Characters');
 } else if (strongRegex.test($(this).val())) {
  $('#passstrength').className = 'ok';
  $('#passstrength').html('Strong!');
 } else if (mediumRegex.test($(this).val())) {
  $('#passstrength').className = 'alert';
  $('#passstrength').html('Medium!');
 } else {
  $('#passstrength').className = 'error';
  $('#passstrength').html('Weak!');
 }
 return true;
});

9. jQuery generates an automatic docked footer effect

// Window load event used just in case window height is dependant upon images
$(window).bind("load", function () {
 var footerHeight = 0,
  footerTop = 0,
  $footer = $("#footer");
 positionFooter();
 
 function positionFooter() {
  footerHeight = $footer.height();
  footerTop = ($(window).scrollTop() + $(window).height() - footerHeight) + "px";
  /* DEBUGGING
console.log("Document height: ", $(document.body).height());
console.log("Window height: ", $(window).height());
console.log("Window scroll: ", $(window).scrollTop());
console.log("Footer height: ", footerHeight);
console.log("Footer top: ", footerTop);
*/
  if (($(document.body).height() + footerHeight) < $(window).height()) {
   $footer.css({
    position: "absolute"
   }).stop().animate({
    top: footerTop
   });
  } else {
   $footer.css({
    position: "static"
   });
  }
 }
 
 $(window)
  .scroll(positionFooter)
  .resize(positionFooter);
});

10. Prevent multiple form submissions

$(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;
 }
 });
});

11. Image scaling, etc

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

0

12, the mouse sliding in and out

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

1

13. Make contour columns

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

2

14. Image pre-loading

(function($) {
 var cache = [];
 // Arguments are image paths relative to the current page.
 $.preLoadImages = function() {
 var args_len = arguments.length;
 for (var i = args_len; i--;) {
  var cacheImage = document.createElement('img');
  cacheImage.src = arguments[i];
  cache.push(cacheImage);
 }
 }
 
jQuery.preLoadImages("image1.gif", "/path/to/image2.png");

15. Get the parameters passed in URL

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

4

16. Disable the enter key for form submission

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

5

17. Make the entire DIV clickable

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

6

18. Open the link in a new window (target= "blank")

var $element = $('#gbtags');
 var $nodes = $element.contents();
 $nodes.each(function() {
  if(this.nodeType === 3 && $.trim($(this).text())) {
  $(this).wrap('');
 }
});

7

You can learn from previous articles on this site and summarize the useful jQuery code snippets for later use.