JQUERY THE NEW DEVELOPMENT

 jQuery is a cross-browserJavaScript library designed to simplify the client-side scripting of HTML.[1] It was released in January 2006 at BarCamp NYC by John Resig. Used by over 27% of the 10,000 most visited websites, jQuery is the most popular JavaScript library in use today.

jQuery is free, open source software, dual-licensed under the MIT License and the GNU General Public License, Version 2.jQuery's syntax is designed to make it easier to navigate a document, select DOMelements, create animations, handle events, and develop Ajax applications. jQuery also provides capabilities for developers to create plugins on top of the JavaScript library. Utilizing these facilities, developers are able to create abstractions for low-level interaction and animation, advanced effects and high-level, theme-able widgets. This contributes to the creation of powerful and dynamic web pages.

Microsoft and Nokia have announced plans to bundle jQuery on their platforms, Microsoft adopting it initially within Visual Studio[6] for use within Microsoft's ASP.NET AJAX framework and ASP.NET MVC Framework while Nokia has integrated it into their Web Run-Time widget development platform.

Features jQuery contains the following features:

• DOM element selections using the cross-browser open source selector engine Sizzle, a spin-off out of the jQuery project
• DOM traversal and modification (including support for CSS 1-3)
• Events
• CSS manipulation
• Effects and animations
• Ajax
• Extensibility through plug-ins
• Utilities - such as browser version and the each function.

Use The jQuery library is usually a single JavaScript file, containing all its common DOM, event, effects, and Ajax functions. It can be included within a web page using the following mark-up:

<script type="text/javascript" src="jQuery.js"></script>

jQuery can also be loaded using the Google AJAX Libraries API with the following mark-up[9]:

<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script>
google.load("jquery", "1.4.2");
</script>


or (HTTPS and HTTP):

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>


Microsoft hosts jQuery on its AJAX CDN (Content delivery network) making it easy to add the support for jQuery library. CDN serves JavaScript libraries from one of thousands of geo-located Microsoft edge-cache servers around the world.

<script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.min.js" type="text/javascript"></script>


jQuery has two usage styles:

• via the $ function, which is a factory method for the jQuery object. These functions, often calledcommands, are chainable; they each return a jQuery object
• via $.-prefixed functions. These are utility functions which do not work on the jQuery object per se.

Typically, access to and manipulation of multiple DOM nodes begins with the $ function being called with aCSSHTML page. This node set can be manipulated by calling instance methods on the jQuery object, or on the nodes themselves. For example:

$("div.test").add("p.quote").addClass("blue").slideDown("slow");


This line finds the union of all div tags with class attribute test and all p tags with CSS class attribute quote, adds the class attribute blue to each matched element, and then slides them down with an animation. The $ and add functions affect the matched set, while the addClass and slideDown affect the referenced nodes.

The methods prefixed with $. are convenience methods or affect global properties and behaviour. For example, the following is an example of the map function called each in jQuery:

$.each([1,2,3], function()
{
document.write(this + 1);
});


This writes the number 234 to the document.

It is possible to perform browser-independent Ajax queries using $.ajax and associated methods to load and manipulate remote data.

$.ajax({
type: "POST",
url: "some.php",
data: "name=John&location=Boston",
success: function(msg){
alert( "Data Saved: " + msg );
}
});