HTML5

advertisement
HTML5 (HYPER TEXT MARKUP
LANGUAGE)
Lab 223
潘建廷 chp32324@hotmail.com
何偉聖 administratorEx@hotmail.com
INTRODUCE




Today, some elements in HTML 4.01 (1999)are
obsolete, never used, or not used the way they
were intended to. These elements are deleted or
re-written in HTML5.
HTML5 is the next generation of HTML.
HTML5 will be the new standard for HTML,
XHTML, and the HTML DOM.
HTML5 is still a work in progress. However,
most modern browsers have some HTML5
support.
GOALS

Document real-world browser behaviour

Document and standardise useful extensions

Develop practical new features

Ensure backwards compatibility

Define robust error handling
DESIGN PRINCIPLES

Foundation of Design and Development

Organised into 3 Categories
Compatibility
 Utility
 Interoperability

DESIGN PRINCIPLES: COMPATIBILITY

Support Existing Content

Degrade Gracefully

Don't Reinvent the Wheel

Pave the Cow paths

Evolution, not Revolution
DESIGN PRINCIPLES: UTILITY

Solve Real Problems

Priority of Constituencies

Media Independence

Universal Access

Support World Languages

Secure By Design

Separation of Concerns
DESIGN PRINCIPLES: INTEROPERABILITY

Well-Defined Behaviour

Avoid Needless Complexity

Handle Errors
BENEFITS OF HTML

Backwards compatible with legacy UAs

Author familiarity

Lenient and forgiving syntax

Convenient shorthand syntax

Can omit some tags and attribute values
BENEFITS OF XHTML

Strict XML Syntax

Integrate directly with other XML vocabularies


SVG, MathML
Use XML Processing
DOCUMENT REPRESENTATIONS

HTML5 will be the new standard for HTML,
XHTML, and the HTML DOM.
HTML5 WERE ESTABLISHED

New features should be based on HTML, CSS, DOM,
and JavaScript

Reduce the need for external plugins (like Flash)

Better error handling

More markup to replace scripting

HTML5 should be device independent

The development process should be visible to the
public
VIDEO
•Ogg = Ogg files with Theora video codec and Vorbis audio codec
•WebM = WebM files with VP8 video codec and Vorbis audio codec
•MPEG4 = MPEG 4 files with H.264 video codec and AAC audio
codec
VIDEO
H.264 SUPPORT IN THE “BIG-5”
VIDEO --VIA HTML5
Example
•The video element allows multiple source elements. Source elements can
link to different video files.
• The browser will use the first recognized format
VIDEO – UI CONTROLS
AUDIO
• Until now, there has never been a standard for playing audio on a web page.
• Today, most audio are played through a plugin (like flash). However, not all
browsers have the same plugins.
• HTML5 specifies a standard way to include audio, with the audio element.
• The audio element can play sound files, or an audio stream.
WEB STORAGE

HTML5 offers two new objects for storing data on
the client:
localStorage - stores data with no time limit
 sessionStorage - stores data for one session

Download