Everything You Need to Get Started with HTML5

Everything you need to know to get you started
with HTML5

By Kevin DeRudder

@kevinderudder working for
eGuidelines and a lecturer at the
Technical University of West Flanders.

Contact me on kevin@e-guidelines.be

Agenda

• About HTML5
• Structure of an HTML5 page
• 30 new tags
• Forms
• Video and audio
• Canvas
• Workers
• If we have time: Data Storage

Thing’s you’ll have to find on your own

• If we didn’t have the time: Data Storage
• WebSockets
• Drag and Drop
• Geolocation
• Offline
• Messaging

The question is: ‘when is HTML5 done?’

For now, just USE HTML5
IT’S READY

if(Modernizr.canvas){ alert('you can use the element');}
else{ alert('not supported');}

if(Modernizr.inputtypes.date){
alert('you can use the element');
}
else{ alert('not supported');}

HTML5 idea on compatibility

• Support existing content
• Degrade gracefully
• <canvas>fallback</canvas>
• <video>fallback</video>
• <datalist> can take a hidden select
• Do not reinvent the wheel
• contenteditable=“” was already used and
implemented
• Adopt widespread practices

• DocType
• Xmlns
• Meta charset
• Link Types

Classic

<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" type="text/css" href="styles.css" />
<title></title>
</head>

<body>
<p>Hello World!</p>
</body>

</html>

DocType

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

<head>
<title></title>
</head>

<body>
<p>Hello World!</p>
</body>

</html>

xmlns

<!DOCTYPE html>

<html>

<head>
<title></title>
</head>

<body>
<p>Hello World!</p>
</body>

</html>

Meta charset

<!DOCTYPE html>

<html>

<head>
<meta charset=“utf-8" />
<title></title>
</head>

<body>
<p>Hello World!</p>
</body>

</html>

Link type

<!DOCTYPE html>

<html>

<head>
<meta charset= "utf-8" />
<link rel="stylesheet" href="styles.css" />
<title></title>
</head>

<body>
<p>Hello World!</p>
</body>

</html>

Article Footer rt
Aside Header Ruby
Audio Hgroup Section
Canvas Keygen Source
Command Mark Summary
Datalist Meter Time
Details Nav Video
Embed Output wbr
Figcaption Progress Bdi
figure rp track

div id=“header”
div id=“topmenu”

div id=“page”

div class=“post”
div id=“sidebar”

div class=“post”

div id=“footer”

footer
menu
title
small
text
content
header
nav
copyright
button
main
search
msonormal
date
smalltext
body
style1
top
white
link

http://code.google.com/intl/nl-NL/webstats/2005-12/classes.html

Opera MAMA Crawler
Class names IDs

Absent presentational elements

<center><font><big>

Also align on <img> <table> etc…
background on <body>
bgcolor on <table>

http://www.w3.org/TR/html5-diff/#absent-elements

HTML4 exists out of dumb fields

/^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;

New attributes and input types available

Use novalidate on form if you want to skip validation

use Form Validation API if you want to check valildity yourself

Validation API

• willValidate
• Validity
• checkValidity()
• validationMessage
• setCustomValidity()

Things that can go wrong

• valueMissing
• typeMismatch
• patternMismatch
• tooLong
• rangeUnderflow
• rangeOverflow
• stepMismatch

Why do we need a video element???

When you wanted to use video, you needed
to use the <object/> tag.

The <object/> tag is for foreign objects and
the video is not foreign

Video - width - height - poster == Audio

Specifications said: all browsers should at least
have built-in support for Ogg Vorbis for audio
and Ogg Theora for movies

So there is no specification for audio and video

And so the developer-browser story
continues

H.264, Theora and VP8 are the most relevant
video codecs

For audio we use MP3, AAC and Vorbis

Theora and Vorbis in an Ogg container
Firefox 4 supports also WebM

Opera 10.6 supports also WebM

Chrome 6 supports also WebM

Anything that Quicktime supports, which is a
long list, but no WebM, Theora, Vorbis

H.264 video and AAC audio supported

Supports all profiles of H.264 and AAC in an
MP4 container

>= IE9

Check with JavaScript
or
Use multiple sources

<video id="theVideo" autoplay controls width="500">
<source src="../videos/big_buck_bunny.mp4" />
<source src="../videos/big_buck_bunny.ogv" />
<source src="../videos/big_buck_bunny.webm" />
<p>Your browser doesn't support video</p>
</video>

video.addEventListener('play' , function () {…;}, false),
video.addEventListener('pause' , function () {…; }, false)

Instead of drawing with a brush, use JavaScript

<canvas width="100" height="100">
<p>Your browser does not support the canvas</p>
</canvas>

Grab the context

var canvas = document.getElementById('theCanvas');
var ctx = canvas.getContext("2d");

ctx.beginPath();
ctx.moveTo(75, 50);
ctx.lineTo(75, 100);
ctx.lineTo(25, 100);
ctx.fill();

context.beginPath();
context.moveTo(100, 100);
context.lineTo(100, 300);
context.closePath();
context.fillStyle = "#0099ff";
context.fill();

context.lineWidth = 6;
context.lineJoin = "round";
context.strokeStyle = "#cccccc";
context.stroke();

context.beginPath();
context.arc(100, 50, 30, 0, Math.PI * 2, true);
context.fill();

var context = canvas.getContext("2d");

var img = new Image(); img.onload = function () {
alert('loaded');
context.drawImage(img, 0, 0, 250, 375);
}

img.src = '../images/Soldier_stub.png';

Lot’s of possibilities

• Transformations
• setTransform
• Rotate, scale, skew, pan, …

• Run over Pixels
• Save canvas content

HTML5 Web Workers

• API for background scripts
• Don’t block the UI Thread
• Not supported in IE
• But in IE10 (thx to @kvdm for feedback)

Restrictions

• No access to DOM
• No access to the window
• No access to the host page

Your storage options in HTML5

• Web Storage
• Web SQL
• IndexedDB
• Cookies

Web Storage

• Session Storage
• Temporary key/value pairs
• One session per tab/window
• Local Storage
• Same as session storage
• Persitant
• Global

IndexedDB

• Object based data store

• Like a database without SQL

• Only vendor prefixed implementations
• Not ready

Thank you for listening

Contact me on kevin@e-guidelines.be

Thank you VISUG
Thank you Combell

Everything You Need to Get Started with HTML5

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