JQuery Presentation

What is jQueryJavascript LibraryFast and ConciseSimplifies the interaction between HTML and JavaScript

Why jQuery ?Cross Browser (IE 6.0+, FF 2+, Safari 3.0+, Opera 9.0+, Chrome)Light WeightSupports AJAXAnimationRich UI

Embed in your page<html> <head> <script src=“path/to/jquery-x.x.x.js"> </script> <script> $(document).ready(function(){ // Start here}); </script> </head> <body> … </body> </html>

jQuery philosophyFind Some Elements$(“div”).addClass(“xyz”);}Do something with themjQuery Object

A Basic Example$(“p”).addClass(“red”);Selects all paragraphs. Adds a class to them.This avoids-<body> <div><p class=“red”>I m a paragraph -1</p> <p class=“red”>I m a paragraph -2</p> </div><p class=“red”>I m another paragraph</p> </body>

Selector BasicsSelecting By Id$(“#header”)Selecting By Class$(“.updated”)Selecting by tag name$(“table”)Combine them$(“table.user-list”)$(“#footer ul.menuli”)

Basic Selector Example$(“ul.menuli”)<body> <div id=“header”> <span id=“logo”>Logo here…</span> <ul class=“menu”><li>user name</li> ….. <li>logout</li> </ul> </div> ……</body>

Jquery Eventsclick(), bind(), unbind(), change(), keyup(), keydown, …..and many moreStart when DOM is ready$(document).ready(function(){ $(selector).eventName(function(){…}); });

Event Example$(document).ready(function(){ $(“#message”).click(function(){ $(this).hide(); })}); <span id=“message” onclick=“…”> blah blah </span>

Iterating thro’ Elements.each()To iterate, exclusively, over a jQuery object$.each()To iterate over any collection, whether it is a map (JavaScript object) or an array.

.each() Example<script type="text/javascript"> $(document).ready(function () { $("span").click(function () {$("li").each(function () { $(this).toggleClass("example"); }); }); });</script>

$.each() Examplevararr = ["one", "two", "three", "four", "five"];varobj = { one: 1, two: 2, three: 3, four: 4, five: 5 }; $(document).ready(function () {jQuery.each(arr, function () { $("#" + this).text("Mine is " + this + "."); return (this != "three"); // will stop running after "three" });jQuery.each(obj, function (i, val) { $("#" + i).append(document.createTextNode(" - " + val)); }); });

$.extend()Merge the contents of two or more objects together into the first object.Syntax$.extend( [ deep ], target, object1, [ objectN ] )deep - If true, the merge becomes recursive.target - The object to extend. It will receive the new properties.object1 - An object containing additional properties to merge in.objectN - Additional objects containing properties to merge in.

$.extend() - ExampleMerge two objects, modifying the firstvar settings = { validate: false, limit: 5, name: "foo" };var options = { validate: true, name: "bar" };jQuery.extend(settings, options);Result:settings == { validate: true, limit: 5, name: "bar" }

$.extend() - ExampleMerge two objects recursively, modifying the first. var settings = { validate: false, font: {family: Arial, size: 12px}, name: “abc" };var options = { validate: true, font: {family: Verdana}, name: “xyz" };jQuery.extend( true, settings, options);Result:settings == { validate: true, font: {family: Verdana, size: 12px}, name: “xyz" }

$.extend() - ExampleMerge defaults and options, without modifying the defaults. This is a common plugin development pattern.var empty = {}var defaults = { validate: false, limit: 5, name: "foo" };var options = { validate: true, name: "bar" };var settings = $.extend(empty, defaults, options);Result:settings == { validate: true, limit: 5, name: "bar" }empty == { validate: true, limit: 5, name: "bar" }

$.fn.extend()Extends the jQuery element set to provide new methods (used to make a typical jQuery plugin).Syntax//You need an anonymous function to wrap around your function to avoid conflict(function($){ //Attach this new method to jQuery $.fn.extend({ //This is where you write your plugin's name pluginname: function() { //Iterate over the current set of matched elements return this.each(function() { //code to be inserted here }); } });

$.fn.extend() - ExampleReverse Text of Odd rows<script type="text/javascript">$(document).ready(function () { $('ulli:odd').reverseText({ minlength: 6, maxlength: 10 }); });</script><body> <form id="form1" runat="server"> <div> <ul id="menu"> <li>Home</li> <li>Posts</li> <li>About</li> <li>Contact Us</li></ul> </div> </form></body>Desired Result

$.fn.extend() - Example(function($) { // jQuery plugin definition $.fn.reverseText = function(params) { //$.fn.extend({ reverseText: function(params) {…// merge default and user parameters params = $.extend( {minlength: 0, maxlength: 99999}, params); // traverse all nodes this.each(function() { // express a single node as a jQuery object var $t = $(this); // find text varorigText = $t.text(), newText = ''; // text length within defined limits? if (origText.length >= params.minlength && origText.length <= params.maxlength) { // reverse text for (vari = origText.length-1; i >= 0; i--) newText += origText.substr(i, 1); $t.text(newText); } }); // allow jQuery chaining return this; }; });

Jquery and AJAXjQuery.ajax() or $.ajax() Performs an asynchronous HTTP (Ajax) request.

jQuery.ajax()The $.ajax() function underlies all Ajax requests sent by jQueryAt its simplest, the $.ajax() function can be called with no arguments: Note: Default settings can be set globally by using the$.ajaxSetup() functionSeveral higher-level alternatives like $.get() and .load() are available and are easier to use. If less common options are required, though, $.ajax() can be used more flexibly.$.ajax();

jQuery.ajax()Syntax $.ajax({ type: type, url: url, data: data, success: success,dataType: dataType });Type that describes whether the request if GET or POST URL of the HTTPHandlerData specifying the querystringSuccess defining a function which manipulates the response from the handler DataTypeDifferent data handling can be achieved by using the dataType option. The dataType can be plain xml, html, json, jsonp, script, or text.

jQuery.ajax() : ExampleSave some data to the server and notify the user once it's complete. $.ajax({ type: "POST", url: "some.aspx", data: "name=John&location=Boston", success: function(msg){ alert( "Data Saved: " + msg ); }});

JQuery Presentation

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