Yearning jQuery

Hi, I’m Remy / @rem

Screencast @
jqueryfordesigners.com

Questions: interrupt me
& ask!

1. Build without jQuery.

2. Design the start and end of your
effects without jQuery.

3. Add jQuery a little at a time.

(a lot of it is...)

"all about CSS"

Me, to many a colleague

@rem
Remy Sharp

Dear designer/dev: if you're using
JavaScript to do a job that CSS could have
done perfectly well, you've lost some
points in my book. Sorry

@rem
Remy Sharp

The day someone loses business because
an animated transition wasn't used to
reveal a screenshot: I'll sell my left nut on
eBay. #cssinstead

What we're covering

• Getting friendly with the $
• DOM navigation & manipulation
• Events
• Ajax
• Tips

APIs Blogs, tutorials, screencasts,
docs.jquery.com
plugins, development sprints
api.jquery.com
visualjquery.com

Twitter forum.jquery.com
@jquery Help!
@jquerysites
@jqueryui
IRC channel
irc.freenode.net/#jquery

It means no more of this
var tables = document.getElementsByTagName('table');
for (var t = 0; t < tables.length; t++) {
! var rows = tables[t].getElementsByTagName('tr');
! for (var i = 1; i < rows.length; i += 2) {
if (!/(^|s)odd(s|$)/.test(rows[i].className)) {
rows[i].className += ' odd';
}
}
}

jQuery simplifies

$('table tr:nth-child(odd)').addClass('odd');

jQuery simplifies

jQuery function


jQuery simplifies

jQuery function


CSS expression

jQuery simplifies

jQuery function jQuery method


CSS expression

• Firefox: Firebug (& FireQuery*)
• Safari & Chrome: Web Inspector
• Opera: DragonFly
• IE: Web Developer Toolbar

Tip

$.fn.jquery

(little 'q')

Let's play.

http://twitter.com

jQuery on every site?
No Problem.

Hosting options
• Host it yourself (good for offline
dev)

• Hotlink it:
• Media Temple
• Microsoft
• Google (my pick)
http://docs.jquery.com/Downloading_jQuery

Tip: keep a copy on
your machine

• jQuery first
• Then jQuery plugins
• Then your code

• Other JavaScript libraries
• jQuery last library
• Then jQuery plugin scripts
• Then your code

<html>
<head>
<styles>
Styles first 
let's the page </styles>
</head>
render
<body>
without <content>
scripts 
</content>
blocking
<behaviour>
</behaviour>
</body>
</html>

<html>
<head>
<styles>
Then your </styles>
content, </head>
again so that <body>
<content>
it's delivered

to your </content>
visitor as <behaviour>
early as
</behaviour>
possible </body>
</html>

<html>
<head>
<styles>
</styles>
</head>
<body>
Finally, add
<content>
your 
behaviour, </content>
the jQuery <behaviour>
and sexy
</behaviour>
magic jazz. </body>
</html>

$(document).ready(function () {

// < YOU >

});

$(function () {

// < YOU >

});

Tip
jQuery(function ($) {

// < YOU >

});

Useful when giving code to a client

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset=utf-8 />
<title>My first jQuery page</title>
</head>
<body>
<h1>Remy woz 'ere</h1>
<p>Lorem ipsum dolor sit amet.</p>
<script src="jquery.min.js"></script>
<script>
$(function () {
// < YOU >
});
</script>
</body>
</html>

jQuery('table tr:nth-child(odd)')

$('div').show().hide().slideUp().slideDown();


Get the divs,


and show them,


now hide them,


and then slide them up,


then finally slide them down.

Can't chain text getters

.val() .html() .text() .css(prop) .attr(prop), etc

Gotc ha
& Tip

if ( $('foo') ) {
doAmazing();
}

1) $('foo')
2) $()
3) []
4) [].join(',') // works

if ( $('foo') ) {
doAmazing();
}

if ( $('foo').length ) {
doAmazing();
}

$('el').doStuff
vs
$.doStuff

$('el').doStuff
runs against
everything
matched.

Deprecated

$.browser.version
$.browser.msie
$.browser.safari
$.browser.webkit

$('a').click(function () {
alert('I got clicked');
return false;
});

return false;
});

Find the anchors

return false;
});

when they're clicked

return false;
});

run this function - don't worry
about the crazy syntax.

return false;
});

Cancel the browser's default
action, which is to redirect.

$('a').click(function(event){
event.preventDefault();
});

Same thing as cancelling (almost),
this is useful for debugging.

• click, dblclick
• mousedown, mouseup, mousemove
mouseover, mouseout, mouseenter
mouseleave

• keydown, keypress, keyup
• submit, change, blur, focus, select
• scroll, resize, load, error

A tabbing system is...

• A group of "panels"
• Tabs (or links) pointing to a panel
• Clicking tab, hides all panels, then
shows just one

...the content can
also be be Ajaxy

this is the element
that the event is
happening to.

console.log(this);
});

this is the anchor element, not the jQuery
wrapped element.

Common mistake
setTimeout(function () {
$(this).text("I'm alive!");
}, 1000);
});

Common mistake
$(this).text("I'm alive!");
}, 1000);
});

this is the window object, not the link

Common mistake
var el = this;
$(el).text("I'm alive!");
}, 1000);
});

Live codin' time!

tabs.html

$('input').keydown(function (event) {
// what's the event arg?
});

•.keyup(fn), .click(fn), etc
•.bind(type, fn)
•.trigger(type), unbind(type)
•.one(type, fn)

$.event.special.click = {
setup: function() {
$(this).css('cursor','pointer');
return false;
},
teardown: function() {
$(this).css('cursor','');
return false;
}
};

All credit to David Walsh

<h1>Super Ted</h1>
<img src="superted.jpg">
When the
<img src="spotty.jpg">
page has <img src="txspete.jpg">
finished <script src="jquery.js">
<script>
loading, the
$('img').click(function(){
jQuery runs showDetails(this);
});
</script>

<h1>Super Ted</h1>
Clicking <img src="superted.jpg">
these images
<img src="txspete.jpg">
"shows <script src="jquery.js">
details" <script>
showDetails(this);
});
</script>

<h1>Super Ted</h1>
Now Ajax <img src="spotty.jpg">
(or something <img src="txspete.jpg">
else) add new <script src="jquery.js">
<script>
images to the $('img').click(function(){
page showDetails(this);
});
</script>

<h1>Super Ted</h1>
Now Ajax <img src="spotty.jpg">
(or something
<img src="mothernature.jpg">
else) add new <script src="jquery.js">
images to the <script>
page
showDetails(this);
});
</script>

<h1>Super Ted</h1>
Clicking this <img src="txspete.jpg">
image doesn't <img src="mothernature.jpg">
do anything. <script src="jquery.js">
<script>
showDetails(this);
});
</script>

<h1>Super Ted</h1>
<script src="jquery.js">
<script>
$('#superTed').delegate('img','click',function(){
showDetails(this);
});
</script>

These images
are loaded after
the DOM has
loaded via Ajax

We're going to "delegate" the
task of listening for particular
events to this <div>

We've "delegate" clicks,
looking for the "img" selector

$('div').delegate('img','click',function(){
/* do funky stuff */
});

Now, any new images inserted in this
<div> can be clicked and will fire the
"funky stuff" function

Ajax Warning: wear your tech-hat

$('#detail').load('page.html');

$('#detail').load('page.html #id');

1. Ajax load the page

2. Search for the selector passed
(#dizzy)

3. Squirt contents found into original
selector

$('#tabs a').click(function (event) {
// this.pathname = 'ajax-load-detail.html'
$('#detail').load(this.pathname);
return false;
});

this.hash

$('#tabs a').click(function (event) {
$('#detail').load(this.pathname + ' ' +
this.hash);
return false;
});

JavaScript Object
{
screen_name : "@rem",
height : "short",
fingers : 5,
brit : true
}

JSON
{
"screen_name": "@rem",
"height": "short",
"fingers": 5,
"brit": true
}

JSON+...
{
"height": "short",
"fingers": 5,
"brit": true
}

JSON+Padding
callback({
"height": "short",
"fingers": 5,
"brit": true
});

$(document).ready(function () {
$.getJSON('http://twitter.com/statuses/user_timeline/rem.json?callback=?',
function (data) {
$('#tweets').empty();

$.each(data, function (i, item) {
$('#tweets').append('<li class="tweet">' + item.text + '</li>');
});
});
});

Loading...

Giving users
feedback

Ajax order

1. ajaxStart

2. ajaxSuccess (or ajaxError)

3. ajaxComplete

http://api.jquery.com/?s=ajax

$('#status').ajaxStart(function () {
$(this).fadeIn();
}).ajaxComplete(function () {
$(this).fadeOut();
});

$.get('foo.html', function (html) {
var jqXHR = $.get('foo.html');
$('#latest').append(html);
});
jqXHR.done(function (html) {
$('#latest').append(html);
});

$.ajax({
url: 'foo.json',
dataType: 'json',
success: function () {
// this === xhr
},
error: function () {

}
});

$.ajax({
url: 'foo.json',
dataType: 'json',
context: document.body,
success: function () {
// this === body element
},
error: function () {

}
});

var jqXHR = $.ajax({
url: 'foo.json',
dataType: 'json',
context: document.body
});

jqXHR.then(success, fail);

url: 'foo.json',
dataType: 'json',
});

jqXHR.then(success, fail);

// much later in the code

jqXHR.done(success2);

url: 'foo.json',
dataType: 'json',
});

// much later in the code

jqXHR.done(success);

.done(ok) // success
.fail(fail) // error
.always(fn) // complete
.then(ok, fail)

What’s a plugin?
A plugin is nothing more than a
custom jQuery method created to
extend the functionality of the jQuery
object

$(‘ul’).myPlugin()

Step 1:
create a private
scope for $ alias

<!DOCTYPE html><html><body>
<script src=”jquery.js”></script>
<script>
(function ($) {

})(jQuery);
</script></body></html>

Step 2:
attach plugin to fn
alias (aka prototype)

<p>I hate jQuery!</p>
<script>
(function ($) {
$(this).text(
);
}; // end of plugin
})(jQuery);

$(‘p’).notHate();

Step 3:
add implicit iteration

<p>I mean really hate jQuery!</p>
<script>
(function ($) {
this.each(function () {
$(this).text(
);
});
}; // end of plugin
})(jQuery);


<!DOCTYPE html><html><body> http://jsbin.com/ifuga/edit
<script>
(function ($) {

$(this).text(
➥ settings.text)
);
});
}; // end of plugin
})(jQuery);


$.fn.myplugin = function () {
var me = $(this).each(function() {
return $(this).bind('someEvent', function () {
// does something
});
});

return me;
};

var me = $(this).each(fn);

return me;
};

return $(this).each(fn);
};

return $(this).each(function() {
// does something
});
});
};

return this.each(function() {
// does something
});
});
};

return this.each(function() {
$(this).bind('someEvent', function () {
// does something
});
});
};

return this.bind('someEvent', function () {
// does something
});
};

(function ($) {
return this.bind('someEvent', function () {
// does something
});
};
})(jQuery);

Questions?
To contact me after my presentation
– text NHT to INTRO (46876)

Or --
remy@leftlogic.com
@rem

Yearning jQuery

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