JQuery tips and tricks

Who doesn’t like JQuery? This fast and easy to use Javascript framework became very popular in 2008. In the following article, I have compiled a list of 8 absolutely useful JQuery hacks, tips and tricks.
Target blank links

Do you use the target=blank attribute on links? If yes, you might know that XHTML 1.0 Strict don't allow it. A good solution to this problem should be using JQuery to make links opening in new windows:

$('a[@rel$='external']').click(function(){
this.target = "_blank";
});

/*
Usage:
<a href="http://www.lepinskidesign.com.br/" rel="external">lepinskidesign.com.br</a>
*/

Get the total number of matched elements

That what I call a very simple, but very useful tip: This will return the number of matched elements:

$('element').size();

Preloading images

When you're using images in Javascript, a good thing is to preload it before you have to use it. This code will do the job:

jQuery.preloadImages = function()
{
for(var i = 0; i").attr("src", arguments[i]);
}
};

// Usage
$.preloadImages("image1.gif", "/path/to/image2.png", "some/image3.jpg");

Detect browser

Although it is better to use CSS conditionnal comments to detect a specific browser and apply some css style, it is a very easy thing to do with JQuery, which can be useful at times.

//A. Target Safari
if( $.browser.safari ) $("#menu li a").css("padding", "1em 1.2em" );

//B. Target anything above IE6
if ($.browser.msie && $.browser.version > 6 ) $("#menu li a").css("padding", "1em 1.8em" );

//C. Target IE6 and below
if ($.browser.msie && $.browser.version <= 6 ) $("#menu li a").css("padding", "1em 1.8em" );

//D. Target Firefox 2 and above
if ($.browser.mozilla && $.browser.version >= "1.8" ) $("#menu li a").css("padding", "1em 1.8em" );

Remove a word in a text

Do you ever wanted to be able to remove words in a text? Note that the following code can be easily modified to replace a word by another.

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

Columns of equal height

This seems to be a highly-requested hack: How to use two CSS columns, and make them having exactly the same height? Happilly Rob from cssnewbie have the solution.

function equalHeight(group) {
tallest = 0;
group.each(function() {
thisHeight = $(this).height();
if(thisHeight > tallest) {
tallest = thisHeight;
}
});
group.height(tallest);
}

/*
Usage:
$(document).ready(function() {
equalHeight($(".recent-article"));
equalHeight($(".footer-col"));
});
*/

Source: Equal Height Columns with jQuery
Font resizing

Font Resizing is a very common feature in many modern websites. Here's how to do it with JQuery.

$(document).ready(function(){
// Reset Font Size
var originalFontSize = $('html').css('font-size');
$(".resetFont").click(function(){
$('html').css('font-size', originalFontSize);
});
// Increase Font Size
$(".increaseFont").click(function(){
var currentFontSize = $('html').css('font-size');
var currentFontSizeNum = parseFloat(currentFontSize, 10);
var newFontSize = currentFontSizeNum*1.2;
$('html').css('font-size', newFontSize);
return false;
});
// Decrease Font Size
$(".decreaseFont").click(function(){
var currentFontSize = $('html').css('font-size');
var currentFontSizeNum = parseFloat(currentFontSize, 10);
var newFontSize = currentFontSizeNum*0.8;
$('html').css('font-size', newFontSize);
return false;
});
});

Source: Text Resizing With jQuery
Disable right-click contextual menu

There's many Javascript snippets available to disable right-click contextual menu, but JQuery makes things a lot easier:

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