Using jQuery allows developers to: 1) Fix cross-browser problems and solve CSS shortcomings and limitations by extending CSS functionality with JavaScript. 2) Solve "real world" problems like creating hover effects, animations, and interactions that are not possible with CSS alone. 3) Benefit from a large community and ecosystem that continues to improve and expand jQuery's capabilities.

1. Using jQuery
to Extend CSS
• Fix Cross Browser Problems
• Solve CSS Shortcomings
• Do Things CSS Can’t Do
• Solve ‘Real World’ Problems
• Get Your Site into an Environment with a Bright Future

2. Why jQuery?
• What about MooTools? Prototype? (go for it!)

3. Transparency
With CSS:
.transparent_class {
/* IE 8 */
-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
/* IE 5-7 */
filter: alpha(opacity=50);
/* Netscape */
-moz-opacity: 0.5;
/* Safari 1.x */
-khtml-opacity: 0.5;
/* Good browsers */
opacity: 0.5;
}
• Messy
• Invalid

4. Transparency
With jQuery:
$(“.transparent_class”).css(“opacity”, “0.5”);
• Clean
• Valid

5. Hover
With CSS:
div {
background: white;
}
div:hover {
background: #eee;
}
• Not supported in IE <= 6
• Limited...

6. Hover
With jQuery
$(“div”).hover(function(){
$(this).addClass(“hover”);
}, function(){
$(this).removeClass(“hover”);
});
• All Browser Support
• More Options
$(“div”).hover(function(){
$(this).addClass(“hover bookHighlight”);
}, function(){
$(this).removeClass(“hover bookHighlight”);
});

7. Attribute & Psuedo Selectors
HTML
<input type=”text” ... /> <ul>
<input type=”radio” ... /> <li><a href=”#”>List Item One</a></li>
<input type=”submit” ... /> <li><a href=”#”>List Item Two</a></li>
<input type=”checkbox” ... /> <li><a href=”#”>List Item Three</a></li>
<input type=”password” ... /> </ul>
CSS
input[type=text] { ul li {
width: 250px; border-bottom: 1px solid #ccc;
border: 1px solid #ccc; }
padding: 3px;
} ul li:last-child {
border-bottom: 0;
input[type=radio] { }
vertical-align: middle;
}
• Not supported in IE <= 6

8. Attribute & Psuedo Selectors
With jQuery
$(“input[type=text]”) $(“ul li:last-child”)
.addClass(“textInput”); .addClass(“last”);
(Still handle styling with CSS)
<form> $(“input[type=text]”)
<div> .focus(function(){
<label>Name</label> $(this).parent().addClass(“formFocus”);
<input type=”text” /> })
</div> .blur(function(){
<div> $(this).parent().removeClass(“formFocus”);
<label>Email</label> });
<input type=”text” />
</div>
...

9. Looks Simple?
Grids are hard
...when not
tabular data.
...and especially
with variable
height content
Div has a hover state
...with opacity change
...and is a link.
Need right margin Doesn’t need right margin

10. Looks Simple?
HTML
<div class="book">
<h3>Book Title</h3>
<p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac
turpis egestas.</p>
<a href="http://google.com">Learn More</a>
</div>
CSS
.book {
width: 120px;
float: left;
padding: 10px;
border: 1px solid #ccc;
margin: 0 10px 10px 0;
}

11. Looks Simple?
$(function() {
$(".book:nth-child(4n+1)").css("margin-right","0px");
$(".book a").hide();
var maxHeight = 0;
$(".book").each(function(){
if ($(this).height() > maxHeight) { maxHeight = $(this).height(); }
$(this).css("opacity", "0.7");
});
$(".book").height(maxHeight);
$(".book").hover(function(){
$(this)
.addClass("hover")
.css("opacity", "1.0");
}, function(){
$(this)
.removeClass("hover")
.css("opacity", "0.7");
});
$(".book").click(function(){
window.location = $(this).find("a").attr("href");
});
});

12. Looks Simple?
$(function() {
$(".book:nth-child(4n+1)").css("margin-right","0px");
$(".book a").hide();
var maxHeight = 0;
var books = $(".book");
books
.each(function() {
if ($(this).height() > maxHeight) { maxHeight = $(this).height(); }
$(this).css("opacity", "0.7");
})
.height(maxHeight)
.hover(function() {
$(this)
.addClass("hover")
.css("opacity", "1.0");
}, function() {
$(this)
.removeClass("hover")
.css("opacity", "0.7");
})
.click(function() {
window.location = $(this).find("a").attr("href");
});
});

13. Table Tricks
• Zebra Striping
• Row / Column Highlighting

14. Table Tricks
$(function() {
$("tr:odd").addClass("odd");
var i = 0;
$("colgroup").each(function() {
i++;
$(this).attr("id", "col"+i);
});
var totalCols = i;
i = 1;
$("td")
.each(function() {
$(this).attr("rel", "col"+i);
i++;
if (i > totalCols) { i = 1; }
})
.hover(function() {
$(this).parent().addClass("hover");
var curCol = $(this).attr("rel");
$("#"+curCol).addClass("hover");
}, function() {
$(this).parent().removeClass("hover");
var curCol = $(this).attr("rel");
$("#"+curCol).removeClass("hover");
});
});

15. Table Tricks
$(function() {
$("tr:contains('Hood')").addClass("found");
});

16. Table Tricks
Plugins!
Tablesorter 2.0 by Christian Bach
http://tablesorter.com/docs/

17. Animation is Easy
• It’s cool... but it’s flair.
• It’s (nearly) useless without JS.

18. Animation is Easy
$(function() {
$("#page-wrap").append('<img src="/images/expando-tab.png" alt="" id="expando-tab" />');
$('#expando').load('/expando.html');
$("#expando-tab").click(function(){
$("#expando").slideToggle();
});
});

19. Animation is Easy
Regular State (overflow: hidden;)
Expanded State
var baseWidth = $("pre")[0].width(),
<pre><code>
rightPadding here...
... code in = 10;
</code></pre>
$("pre").hover(function() {
var codeInnerWidth = $("code", this).width() + rightPadding;
if (codeInnerWidth > baseWidth) {
pre
$(this)
{
overflow: hidden;
.stop()
width:
.css({
563px;
}
zIndex: "100",
code
{
position: "relative"
font-family: Courier, Monospace;
})
}
.animate({
width: codeInnerWidth + "px"
});
}
}, function() {
$(this).stop().animate({
width: baseWidth
});
});

20. Loading after Loading
Big ass movie
Starts loading right away,
slows down page.
$(window).bind(“load”, function() {
$('#movie-area').load('/movie.html');
});
Bonus
If users don’t have
JavaScript, the movie isn’t
going to play correctly
anyway. So nothing is shown.

21. Controlling Outside Content
Design is one thing...
Content is another. CSS was
able to control the new
graphics, but the change in
text was done with jQuery.

22. Controlling Outside Content
$(function() {
$('#coupon-link').text('Enter Voucher Code');
$('#coupon-input').css('display', 'inline');
});

23. MMMmmm Plugins
Facebox
http://famspam.com/facebox
Tablesorter
http://tablesorter.com/
Coda Slider
http://www.ndoherty.com/demos/coda-slider/1.1.1/
markItUp!
http://markitup.jaysalvat.com/home/
jQuery UI
http://jqueryui.com/
Interactions Widgets Effects
• Draggable • Accordion • Show/Hide Methods
• Droppable • Datepicker • Toggle Class
• Resizable • Dialog • Color Animation
• Selectable • Progressbar
• Sortable • Slider
• Tabs

24. The FUTURE
jQuery CSS
Dec. 17 1996 - CSS 1
May 12 1998 - CSS 2
Jan. 14 2006 – jQuery Announced
Aug. 26 2006 - jQuery 1.0
Jan. 14 2007 - jQuery 1.1
Jul. 19 2007 - CSS 2.1
Sep. 10 2007 - jQuery 1.2
May 24 2008 - jQuery 1.2.6
Feb. 20 2009 - jQuery 1.3.2
Apr. 23 2009 - CSS 2.1
??? - CSS 3
Released Usable Recommendations
Versions

25. The FUTURE
• Huge community of people USING it.
• Huge community of DEVELOPERS.
• Loads of DOCUMENTATION.
• Plenty of SUPPORT available.
• Gosh darn it, people like it!