by http://webgeektutorials.blogspot.com

Monday, January 10, 2011

jQuery a Quick Intro

jQuery is JavaScript Library created by John Resig in 2006 with a great idea, and idea was :

Write less, do more

jQuery simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. jQuery is a framework built using JavaScript capabilities. So you can use all the functions and other capabilities available in JavaScript.Here is the list of important core features supported by jQuery:

DOM manipulation: The jQuery made it easy to select DOM elements, traverse them and modifying their content by using cross-browser open source selector engine called Sizzle.
Event handling: The jQuery offers an elegant way to capture a wide variety of events, such as a user clicking on a link, without the need to clutter the HTML code itself with event handlers.
AJAX Support: The jQuery helps you a lot to develop a responsive and feature-rich site using AJAX technology.
Animations: The jQuery comes with plenty of built-in animation effects which you can use in your websites.
Lightweight: The jQuery is very lightweight library - about 19KB in size ( Minified and gzipped ).
Cross Browser Support: The jQuery has cross-browser support, and works well in IE 6.0+, FF 2.0+, Safari 3.0+, Chrome and Opera 9.0+



How to install jQuery ?

This is very simple to do require setup to use jQuery library.Go to the download page to download latest version available and put downloaded jquery-1.4.4.min.js file in a directory of your website, e.g. /scripts.

The jQuery does not require any special installation and very similar to JavaScript, we do not need any compilation or build phase to use jQuery.



How to use jQuery library?

Now you can include jquery library in your HTML file as follows:

<html>
<head>
<title>Hello jQuery</title>
   <script type="text/javascript"   src="/scripts/jquery-1.4.4.min.js"></script>
   <script type="text/javascript">
      // you can add other javascript code here
   </script>  
</head>
<body>
 </body>
</html>

How to call a jQuery library functions?

When using it, jQuery reads or manipulates the document object model (DOM), we need to make sure that we start adding events etc.
If you want an event to work on your page, you should call it inside the $(document).ready() function. Everything inside it will load as soon as the DOM is loaded and before the page contents are loaded.

To do this, we register a ready event for the document as follows:

$(document).ready(function() {
   // some statements.
 });

To call upon any jQuery library function, use HTML script tags as shown below:

<html>
<head>
<title>Hello jQuery</title>
   <script type="text/javascript"  src="/scripts/jquery-1.4.4.min.js"></script>
  
   <script type="text/javascript" language="javascript">
   // <![CDATA[
   $(document).ready(function() {
      $("div").click(function() {
        alert("Hello jQuery!");
      });
   });
   // ]]>
   </script>

</head>
<body>
<div id="jqdiv">
Click here in this line.
</div>
</body>
</html>


Done !

No comments:

Post a Comment