August 25th 2010: HTML 5: The Hype and Some Alternative Realities

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August 25th 2010: HTML 5: The Hype and Some Alternative Realities

John R Hudson

Posted on August 27, 2010

( 4 minute read )

David Fisher and Jeff introduced HTML5, saying that it was estimated that HTML5 will only receive full approval in 2022 because W3C standards now require full compliance from two browsers.

The aims of HTML5 were to tackle all the crap people never fixed in the past and to add stuff that is missing. It is not one big thing but lots of features and APIs and many separate specifications. It makes it easy to detect browser support and most things in IE are fixable in JavaScript. It is fully backwards compatible; it handles older browser features sensibly and HTML4 markup is treated sensibly.

Many of the new features are already in Firefox, Safari, Opera, Chrome, IE9, e.g. canvas, video, geolocation, local storage, microdata. It’s here for good, XHTML2 was killed in October 2009.

Aims

fix what is broken – inconsistent error handling
add what is missing – semantics → lots of new tags, multimedia, application support.

New markup

structural/semantic

New functionality

New

doctype <!DOCTYPE html> puts all browsers in standards mode
simple root language <html lang= "en"> works in all browsers
charset metadata

semantic markup

<body>
    <header> ... </header>
    <nav> ... </nav>
    <article>
        <section>
            ...
        </section>
        <section>
            ...
        </section>
    </article>
    <aside> ... </aside>
    <footer> ... </footer>
</body>

[ HTML_page ]

HTML page: n.b. to remove a whole page: take out <article>…</article>

Modifications

rel attributes can be simpler, e.g. archive, icon, sidebar – registry of permitted rel attributes
and reserved for unusual cases

Sub-sectioning: clarifies section levels – also headings within sections

<section>
    <hl>\level 1\,/hl>
    <section>
        <hl>\level 2</hl>
        <section>
            <hl>level 3</hl>
        </section>
    </section>
</section>

The choice of reserved words was based on popularity and genericism.
...
lots of formats, pubtime option [since removed].
IE<9 won’t apply CSS styles to unknown elements: fix – tell IE that an element exists and IE will treat it properly; in other words, because IE fails to obey HTML rules, the fix works by using an example of IE abuse of HTML rules.

Deprecated

mostly presentational stuff: , , ... , ... , <applet>, ,

In use

Modernizer: JavaScript library – detects virtually all HTML5 stuff.
IE7.js handles CSS in IE; now IE9.js allows proper CSS in IE.
video: no agreement yet on codec – use ogg with fallback, e.g. Flash
<canvas width= height= id= > then use JavaScript to draw = replacement for Flash; context to define style of canvas; can copy one image to another canvas → animation
Form input types: url, email, datetime, datetime-local, date, month …
manifest: files cached for use offline

Storage:

sessionStorage, eg. cookies
localStorage, e.g. large chunks of data
databases – n.b. given up on SQL

Other new features

Webworkers: limited multitasking, drag and drop, contenteditable =WYSIWYG, geolocation, autocomplete, esp. autocomplete=off (for bank accounts), spellcheck=false

All browsers will handle rubbish consistently.

Useful websites: Wikipedia on HTML5 and CSS, Living Validator, Dive into HTML5,

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