Intro to jQuery

Eric.Steinborn@dcjs.state.ny.us

Just Thought you should know

Eric Steinborn
IT2P @ NYS Division of Criminal Justice Services since 2006
15+ years experience with web technologies
Work in a group of 3
Maintain our intranet (DCJSnet)
Help with internet and extranet sites
A few things I'm awesome at are:
CSS, JavaScript, Interactivity, Prog Enhancement, UX, SEO, Accessibility
I do what I love -> I love my job!

What is jQuery?
jQuery is an Open-Source JavaScript framework that simplifies cross-browser client side scripting.
Animations
DOM manipulation
AJAX
Extensibility through plugins
jQuery was created by John Resig and released 01/06
Most current release is 1.4.2 (2/19/10)
A Little Bit About jQuery

Why should you use it?
Easy to learn! It uses CSS syntax for selection
Its tiny 71KB (24KB, minified and Gzipped)
Documentedapi.jquery.com & Supported forum.jquery.com
Cross browser compatibility: IE 6+, FF 2+
It is the most used JavaScript library on the web today
39% of all sites that use JavaScript use jQuery.
trends.builtwith.com/javascript/JQuery <- See, I'm not a liar..
A Little Bit About jQuery

I <3 The jQuery Community

PWNS All Other Frameworks

Who Uses jQuery?
docs.jquery.com/Sites_Using_jQuery

Who Uses jQuery In NY?

What is the DOM?
Document Object Model (DOM): noun
Blah blahblah long definition that makes little sense….

What Is The DOM?
Long story short, the DOM is your html document code. From the
<!DOCTYPE> to the </html>
The DOM is loaded top to bottom, so include your scripts at the bottom of the page for best performance.
The DOM is "ready" when everything on the page has loaded.
Stylesheets
JavaScripts
Images

Wait!!
In order to make sure that jQuery can find the element you asked it for, your browser needs to have loaded it (the DOM needs to be ready).
Q. How can I be sure my code runs at DOM ready?
A. Wrap all your jQuery code with the document ready function:
$(document).ready(function(){
// insert sweet, sweet jQuery code here…
});

And What If I Don't Wanna, Huh?
1 of 3 things will happen:
Code doesn't work, throws an error (90%)
Code works… this page load, next page load see #1. (~9%)
Code opens a worm hole that transports your page back to 1990 revolutionizing the Web as we know it. While seemingly great, it also creates a paradox and destroys the universe. * (<1%)
*(has yet to be fully verified)

We get it Eric, you're a geek…Get to the jQuery already!
Your about ta get a wedgie NERD!*
*spelling intentional

Loading jQuery
In order to use jQuery you need to load it.
You can include it locally on your own server:
<script src="/js/jquery.js">
Or use one of the CDN's made available:
ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js
ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js
CDN's are Gzipped and minified

Load Scripts At The Bottom
Problem:
When scripts are downloading they block everything else in almost all browsers!
Solution:
Best practice: Load your scripts at the bottom of your page so they don't interrupt page content downloads.

And BOOM! Goes The Dynamite.
jsbin.com/ecayo3/18#slide19
Html:
<p>Hello World! I'm Eric</p>
Script:
$(function(){
$("p").addClass("isCool");
//keep telling yourself that..
});
Resulting html:
<p class="isCool">Hello World! I'm Eric</p>

Break It Down Now!
$
("p")
.addClass("isCool");
Grabs a DOM element using a CSS selector.
Built in method that adds a class to the jQuery Collection
$(function(){// = $(document).ready(function(){
Initiates the jQuery function
Selector is in quotes.
Class is in quotes.
Creates a jQuery “Collection”
$
=
jQuery
ends with a semicolon.
<p>
});

All Your Basic Selectors Are Belong To Us
Uses the same syntax you use to style elements in CSS!
api.jquery.com/category/selectors/

Get Classy <p>
jQuery:
$("p").addClass("sophisticated");
Before:
<p>
After:
<p class="sophisticated">

This <p> Has No Class At All!
jQuery:
$("p").removeClass("sophisticated");
Before:
<p class="sophisticated">
After:
<p class="">

<div> Hide and Seek
jQuery:
$("div").show();
Before:
<div style="display:none;">
After:
<div style="display:block;">

I’m Not Lame, Am I?
jQuery:
$("#eric").text("Is Cool");
Before:
<p id="eric">Is Lame</p>
After:
<p id="eric">Is Cool</p>

You Can Chain Most Methods Together
$("p")
.addClass("sophisticated")
.text("Hello World!")
.show();

Click Events Are Awesome!
$("#eric").click(function(){
$(this).text("Is Cool"); // this = #eric
alert("Take that High School!");
});
$("#eric").click(function(event){
$(this).text("Is Cool"); // this = #eric
alert("Take that High School!");
event.preventDefault(); //Prevents default action
});

Some of Basic Methods
api.jquery.com/

Getters and Setters

Dual Purpose Methods

Use jQuery To Get
<p>Eric</p>

Use jQuery To Set
<p>Eric</p>

Questions?

Plugins

Viva Variety!
“If you want to create an animation, effect or UI component, chances are pretty good that someone has done your work for you already.”
-Eric Steinborn 2010
plugins.jquery.com

I Will Be Covering These Plugins

That's Just Typical..
Download the plugin from its site.
Depending on the plugin you can have 1 or more files to install.
Copy the plugin, and any of its dependencies to your server.
If needed call css <link href="plugincss.css" />
Call jQuery <script src="jQuery.js">
Call the plugin <script src"jQuery.pluginname.js">
Initialize plugin $("#mypluginContainer").pluginInit();

Go-Go-Get ColorBox!
Go to colorpowered.com/colorbox/
This is what you'll get

Go-Go-Install ColorBox!
Extract min.js to my "/js/plugins/" folder
I like example 2 so I'll extract
These to my /css/ folder

Go-Go-Prep ColorBox!
In the <head> type:
<link rel="stylesheet" href="css/colorbox.css" media="screen" />
In the <body> type:
<a href="unicorn.jpg" rel="colorbox"><imgsrc="unicorn-t.jpg" /></a>
<a href="rainbows.jpg" rel="colorbox"><imgsrc="rainbows-t.jpg" /></a>
<a href="sparkles.jpg" rel="colorbox"><imgsrc="sparkles-t.jpg" /></a>
Before the ending </body> type:
<script type="text/javascipt" src="js/jquery.js"></script>
<script type="text/javascipt" src="js/jquery.colorbox-min.js"></script>
<script type="text/javascipt"></script>

Go-Go-Gadget ColorBox!
Inside the empty <script> tag I just entered I'll init ColorBox
<script>
$(function(){
$("a[rel='colorbox']").colorbox();
});
</script>
Now anytime I click on a thumbnail, I’ll see a ColorBox with my image in it.

Go-Go-Cut It Out Already!
Set custom options for ColorBox like this:
$("a[rel='colorbox']").colorbox({
slideshow: true, // shows all your images in sequence
slideshowSpeed: 5000, // set the speed of the slideshow in MS
transition: "fade",// set the transition between images
speed: 1000// set the speed of the transition in MS
});
Download ColorBox @ colorpowered.com/colorbox/

tablesorter
Head:
<link href="css/tablesorter.css" />
HTML:
<table id="ericsDreams"></table>
Foot:
<script src="js/jquery.tablesorter.min.js"></script>
<script>
$(function(){
$("#ericsDreams").tablesorter();
});
</script>

tablesorter Options
http://jsbin.com/ecayo3/18#slide43
Set custom options for tablesorter like this:
$("#ericsDreams").tablesorter({
widgets: ['zebra']// Zebra stripes alternating rows
});
Download tablesorter @ tablesorter.com/docs/

ListNav
Head:
<link href="css/listnav.css" />
HTML:
<div id="ericsDreams-nav"></div> 
<ul id="ericsDreams"></ul>
Foot:
<script src="js/jquery.listnav.min.2.1.js"></script>
<script>
$(function(){
$("#ericsDreams").listnav();
});
</script>

ListNav Options
Set custom options for ListNav like this:
$("#ericsDreams").listnav({
showCounts: false, // Don’t show counts above letters
noMatchText: "Fail!", // Custom text for invalid selections
cookieName: "Dreams", // Selection saved in Cookie
includeOther: true// Include an Other option [~!@#]
});
// include cookie plugin for cookieName to function
Download ListNav @ ihwy.com/Labs/jquery-listnav-plugin.aspx

Great References
John Resig's introduction slides
jQuery 1.4 Cheat Sheet
jQuery API
jQuery Forums
YAYquery Podcast (explicit)
DEMOS:
jsbin.com/ecayo3/18
eric.steinborn@dcjs.state.ny.us

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Intro to jQuery

by Eric Steinborn on Jun 04, 2010

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