Why we need a New Web Standard?
Today, RIA are built using Adobe Flash, JavaFX, and Microsoft Silverlight & AJAX. The availability of so many vendors, and try to achieve the same purpose by different approaches causes trouble in the Web 2.0. There is a need of standardization which can inherently be embedded into all browsers. This can pump up the developer communities effort into more unified technology rather than being biased to specifics.
As per 2008, Out of total web deelopers around the world, 15% are comfortable or atleast developed a single application based on Adobe Flash, AJAX. The number is lowerewd to 2% for Silverlight, 1% for JavaFX. What are we achieving by de-standardization?
Internet Task group took up the challenge to come up with a standard that could tackle this scenario. They have been working for years, and still far from achieving th efinal standard which could redefine the way RIA web 2.0 applications are written. Though some of the features are mature and can be talked about at this part of the time.
HTML 5 provides a number of new elements and attributes that reflect typical usage on modern RIA Web 2.0 Web sites.
– There are semantic replacements for common uses of generic block (<div>) and inline (<span>) elements, for example <nav> (website navigation block) and <footer>.
– Many new functionalities are exposed through a standardized interface, e.g. the audio and video will now be built in supported via <audio> and <video> elements.
– Some deprecated elements from HTML v4.01 have now been removed, including purely presentational elements, such as <font> and <center>, whose effects are supposed to be handled exclusively by CSS in future.
– DOM scripting web behaviour is now more prominent than ever.
– The syntax is no longer based on SGML despite its markup being very close. It has, however, been designed to be backward compatible with common parsing of older versions of HTML. It comes with a new introducing line which looks like an SGML document type declaration, <!DOCTYPE html>, and enables standards-compliant rendering in all browsers that use “DOCTYPE sniffing”.
New Development APIs
Existing Document Object Model (DOM) interfaces are extended. There are new APIs, such as:
- The canvas tag for immediate mode 2D drawing (to compete with Flash 2d graphics)
- Timed media playback (imagine youtube player inbuilt to your browser)
- Offline storage database (like SqlLite)
- Document editing (e.g. MS Doc, Rich Fomatting)
- Drag-and-drop (Files, documents, content, Objects)
- Cross-document messaging (intra browser communication)
- Browser history management (general APIs that let you analyze history for various intelligent decisions whether its URL typing or your flavour of websites)
- MIME type and protocol handler registration (MIME is used for attachments to plain text and now HTML 5 will support it. Other protocol handlers will also find registration with HTML 5 e.g. CORBA)
Changes since HTML 4/XHTML 1
There is a lot that has changed over time. This will summarize on what has changed since 4.01. The following is a list of differences and some specific examples.
- New parsing rules oriented towards flexible parsing and compatibility
- New elements –
section,article,footer,audio,video,progress,nav,meter,time,aside,canvas,datagrid - New types of form controls – dates and times,
email,url,search - New attributes –
ping(onaandarea),charset(onmeta),async(onscript) - Global attributes (that can be applied for every element) –
id,tabindex,hidden - Deprecated elements dropped –
center,font,strike (mentioned earlier)
Approach to Errors & Backward Compatibility
So what happens when an older browser sees a HTML 5 content?
Everything is handled properly in 5. HTML5 is designed so that old HTML 4 browsers can safely ignore new HTML 5 constructs. In contrast to HTML 4, the HTML 5 specification gives detailed rules for lexing and parsing, with the intent that different compliant browsers will produce the same result in the case of incorrect syntax. An HTML5 (text/html) browser will be flexible in handling incorrect syntax, in contrast to the XHTML variant of HTML 5 (XHTML5), where such errors must not be ignored.
What It could mean to Adobe Flash?
Is it the end of Flash,, and all other RIA plugins. NO! Flash is far more superior that HTML 5 is currently targetted for. The flexibility of 2D and 3D renderring exposed in flash is far more advanced than what HTML 5 will see int he years to come.
HTML 5 will provide replacements to small scale usage of Flash, where Flash was used just for basic form handling, data storage, basic graphics, etc.
It CANNOT dream of rolling Flash out of business.
Which Browsers support HTML 5?
To answer this, you need to understand how HTML works. Layout engines are used inside every browser which decides how will a HTML code will be converted into user-presentable form. Most of the browsers use different Layout Engines, being proprietary or open source. Allmost all the broswers on the Desktop support HTML 5, though, the formation is still in the draft stages, not yet usable. You can track the details at wikipedia page.
Dows my Mobile support HTML 5?
Currently on the mobile platform, iPhone is the only one to support HTML 5 with Safari on OS 3.0. Android could be the next one to do it.
VERDICT
HTML 5 could serve threat to some basic applications, but the real purpose of the standard is to make things more generic and better for the internet world.