What can developers expect about HTML5?

Web developers' expectations for HTML5 are getting stronger and stronger. As a document-centered markup protocol, HTML is increasingly unable to meet the needs of modern Web applications. What's more, this protocol has not been updated for more than 10 years. HTML5 aims to solve problems such as interaction, media, and local operations in the Web. Some browsers have already tried to support some features of HTML5, and developers are expected to finally get relief from those Web plug-ins.

However, it should be pointed out that although some heavyweight Web technology manufacturers, such as Apple, Google, Mozilla Foundation, Vimeo, and YouTube, have begun to support this new standard, W3C stated that there is still a long way to go before HTML5, and some of its details There is still controversy. It will take a long time before the mainstream Web switches to HTML5, and developers have to face the dilemma of how to use current technologies to design rich Web applications while preparing for the future. HTML5 Be prepared.

Modern HTML for the Rich Web

There is no good match between rich Web applications and HTML. Tim Berners-Lee, the father of the Web, views HTML this way. It is a markup language used to create platform-independent hypertext documents. With the birth of XHTML, W3C also transformed web pages into considered as documentation.

This annoyed developers who regarded the Web as an application platform. In 2004, Apple, the Mozilla Foundation, and Opera established a Hypertext Application Technology Working Group (WHATWG), seeking to create a standards organization other than the W3C to create a more Web for applications.

In 2007, their XHTML2 was mired in never-ending disputes. Later, the W3C voted to absorb the work of the WHATWG and make it a standard for HTML5. At this time, even Tim Berners-Lee extended an olive branch to the application-oriented Web. , he said, now it seems that those efforts we have made towards XML are ineffective.

This is not to say that pure XML syntax is dead. Although the development direction of HTML has changed, XHTML5 is also in progress at the same time as HTML5. The difference is that XHTML will be suitable for those who have already converted to XML, and for ordinary people Developers do not necessarily use XHTML.

HTML5: Tag changes

HTML5 absorbs some suggestions from XHTML 2, including some features to improve the structure of documents. For example, the use of new HTML tags header, footer, dialog, aside, fugure, etc. will allow content creators to create documents more semantically. Developers always use divs in these situations.

HTML5 also includes some efforts to separate content and presentation. Developers may be surprised that the b and i tags still exist, but their meaning is different from before. The meaning of these tags is just to identify a piece of text. Instead of styling them in bold or italic. The tags u, font, center, and strike have been completely removed.

The new standard applies some new form input objects, including dates, URLs, and email addresses, while others add support for non-Latin characters. HTML5 also introduces microdata, a method of annotating content with machine-readable tags, making processing the Semantic Web simpler. Overall, these structure-related improvements allow content creators to create cleaner, more manageable web pages that are more friendly to search engines, screen-reading software, and more.

Enable a standards-based rich web

However, the most exciting thing about HTML5 is the new APIs that allow developers to implement rich applications, such as graphics, animation, and multimedia. Before HTML5, the implementation of these functions required plug-ins such as Flash, RealMdeia, and QuikTime. These plug-in technologies Not only is it easy to bring security risks, but its audience is limited.

HTML5 solves these problems by using corresponding markup languages. Content creators can use languages ​​like MathML and SVG to create mathematical formulas and graphics. These languages ​​are easier to use across platforms than formats such as Flash and Silverlight.

Web developers will also cheer for the audio and ideo tags of HTML5. These tags allow Web pages to easily embed media. Their encoding standards are neutral, which means that browser manufacturers can use whatever encoding they want to output media, and it The video tag will also benefit mobile browsers that do not support Flash.

The Canvs tag will take interactive Web graphics to a higher level. Developers can use JavaScript to operate objects in the canvas to achieve real-time interactive graphics operations and even interactive games. In addition to these changes that can be seen, HTML5 also introduces browser-based program caching, which caches application data locally (just like the previous Google Gears plug-in). This can not only speed up the running of Web programs, but also enable some programs to run offline. can still be used. In fact, Google is now slowly removing support for Gears and fully moving to HTML5.

Browser plug-ins: Not dead yet

Although HTML5 has introduced so many new features, don't expect those plug-ins to disappear overnight. It will take a long time for pure HTML5 to realize all the functions of the current plug-in world, let alone those old systems that need to continue to be supported. For example, although Vimeo and YouTube have begun to use the video tag to output videos, things are not that simple. The W3C has not determined which encoding scheme to use, which means that those videos are not guaranteed to be viewed on any device. For example, Apple, Google and Microsoft all promote H.264 encoding, but the open source Firefox is not willing because of licensing issues.

In addition, not all old systems will be rewritten in HTML5. For example, although Google itself is no longer optimistic about Google Gears and mainly promotes HTML5, Gooel admits that HTML5 cannot realize all the functions of Google Gears and convert applications based on Google Gears into Pure HTML5 is impossible to implement simply.

Finally, a variety of browsers will also hinder Web developers from moving to HTML5. IE6, older versions of Firefox, Opera, and Safari do not support HTML5. Therefore, unless the vast majority of people's browsers are upgraded to the latest state, otherwise , HTML5-oriented development will still face various difficulties.

early adopters

Although Microsoft has stated that IE9 will support HTML5, they are also cautious about this matter. Microsoft believes that today, when the HTML5 standard has not yet been established, it is inappropriate to say that its browser supports most HTML5 functions. In fact, no organization is more aware of the progress of HTML5 than the W3C. The W3C believes that the HTML5 standard is still not mature, and the establishment of functions will not be completed until 2011. Even then, it will take until 2011 to establish these things as standards. In 2022, that is to say, it will take about 15 years from XHTML1.1 to HTML5.

In any case, HTML5 will be the most cutting-edge technology in the next 5 to 10 years. Those who adopt it early can find a large number of experience sites on the Internet. Currently, the best browsers to experience HTML5 are those based on the Webkit engine, such as Chrome, Safari, and Firefox are not very smooth. Web developers can use the current HTML5 draft to create experimental sites. Of course, there are still some problems with the current browser distribution system. The best HTML5 development resource online is Mark Pilgrim's excellent Dive into HTML5.

HTML5 experience site