New elements in HTML 5

In the new millennium, Hypertext Markup Language (HTML) 5 introduced new elements into HTML for the first time. The new structural elements include aside, figure, and section. The new inline elements include time, meter, and progress. The new inline elements are video and audio. The new interaction elements are details, DataGrid, and command.

The development of Hypertext Markup Language (HTML) was stopped by the 1999 HTML 4. The World Wide Web Consortium has shifted its focus to changing the underlying syntax of HTML from standard Universal Markup Language (SGML) to Extensible Markup Language (XML), as well as the new markup languages of scalable Vector Graphics (SVG), XForms, and MathML. Browser vendors focus on browser features such as tabs and rich-site digest (RSS) readers. Web designers began learning to use asynchronous JavaScript + XML (Ajax) to build their own applications in the existing framework through cascading style sheets (CSS) and JavaScript™ languages. But for the next eight years, the HTML itself has not changed.

Recently, it has risen again. Three key browser vendors-apple, Opera, and Mozilla foundation-have set up Web Hypertext application Technology Working Group (WhatWG) to develop traditional HTML New version. Recently, the consortium has also taken note of these activities and has launched its own new generation of HTML projects, many of which have the same membership. These two projects are likely to be merged eventually. While many details are still being debated, the outline of the next version of HTML is clear.

Web developers have been expecting a new version of HTML since 1999 (usually called HTML 5, but also known as WEB Applications 1.0), which is now finally released. It retains the original features of HTML: no namespaces or patterns. element does not have to end. Browsers will treat errors with tolerance. P is still p,table is still table.

If you freeze a Web developer in 1999 and thaw it now, he will encounter some new, confusing elements. Yes, his familiar elements (such as Div) remain, but HTML now contains new elements such as section, header, footer, and NAV. EM, code, and strong still exist, but add meter, time, and M. IMG and embed are still available, but they also add video and audio. But when he looked closely, he found that the elements were actually no different. Many of these elements may be needed by developers in 1999 and are not available. These new elements are easy to understand by making a simple analogy with the elements he has mastered. In fact, they are very easy to master compared to Ajax or CSS.

Finally, when he opens his 300MHz notebook (which runs Windows 98 and is frozen in 1999), he may be surprised by the new pages displayed in Netscape 4 and Windows®internet explorer®5. Of course, these older browsers do not recognize the new elements and ignore them completely, but the page will still show that the content is still intact.

This is not a fictional story. The design principle of HTML 5 is that it can degrade smoothly in browsers that do not support it. The reason is simple: we are all such "primitive people". Browsers now have tabs, CSS, and XMLHttpRequest, but their HTML display engine still stays at the 1999 level. In addition to the huge increase in user volume, the WEB actually has no progress in nature. HTML 5 takes this into account. It currently has some real benefits for WEB developers, and page viewers will gradually enjoy these benefits as browsers slowly escalate. Let's look at what the HTML 5 provides.

Structure

Because of the lack of structure, even well-formed HTML pages are more difficult to handle. You must analyze the level of the headings to see how each part is divided. Sidebar, footer, header, navigation bar, main content area, and each article are represented by a common div element. HTML 5 Adds a few new elements that are specifically designed to identify these common structures:

Section: This can be a chapter or verse in a book that can actually be anything that has its own title in HTML 4.

Header: Headers displayed on the page; different from head elements

Footer: footer; You can display the signature in an e-mail message

Nav: A set of links to other pages

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