Uncovering the mystery of HTML 5 working draft_HTML/Xhtml_Web page production

The World Wide Web Consortium (W3C) has released a draft of the HTML 5 specification, the first major revision since HTML 4 was released more than a decade ago. During this period, as developers gradually put their Applications have been ported to the Web, which has evolved from a primarily static media to an interactive application with rich media content. The purpose of HTML 5 is to reflect such changes.
New Features are fully considered by application developers. Therefore, HTML 5 introduces a large number of new Javascript APIs. These contents can be associated with corresponding HTML elements. They include:
1/ Two-dimensional drawing API, which can be used On a new Canvas element to render images, game graphics, or other running visual graphics.
2/An API that allows web applications to register themselves as a certain protocol or MIME type.
3/An API that introduces a new caching mechanism to support offline web applications.
4/An API that can play video and audio, using new video and audio elements.
5/A historical record API, which can expose the browsing history, allowing the page to better support the back button in AJAX applications after adding it.
6/Cross-document messaging, it provides a way , allowing documents to communicate with each other regardless of their source domain, 7/To some extent, this design is to prevent cross-site scripting attacks.
8/An API that supports drag-and-drop operations, with which you can Associated with the draggable attribute.
9/ An API that supports editing operations, which can be associated with a new global contenteditable attribute.
10/ A new network API that supports web applications on the local network communicate with each other and maintain bidirectional communication on their origin servers.
Use JavaScript API key/value pairs to implement client-side persistent storage, while supporting embedded SQL databases.
Events sent by the server, through It can be associated with the new event-source element, which facilitates persistent connections to remote data sources and greatly eliminates the need for polling in web applications.
At the same time, HTML 5 also introduces many new presentation elements to support common page components, such as headers (headers), footers (footers), figures (illustrations), dialog (dialog, used to mark sessions) and navigation (navigation) ). In addition, there is a new datagrid element that supports interactive tables and trees, a datalist element for combo boxes, and a progress attribute that can show the completion of a long-running task. At the same time, it also adds Page tags that support RSS feeds.
For forms, the input element type type includes new support for dates, times, emails, and URLs, so that the browser can provide user interface elements, such as a calendar Date picker or integration with the user's address book, while also being able to submit data to the server in a defined format.
HTML 5 also dropped support for some well-known features. The most notable of which is the abandonment support for frames, which have long been considered to undermine the accessibility and usability of web pages. It is worth noting that even if the browser fully supports the HTML 5 standard, it will continue to support these abandoned features. , because support for older versions of HTML will continue for many years.
HTML 5 is developed under the guidance of the W3C's HTML Working Group, which was established in March 2007. The operations of the working group are completely public, and in recent times The 500 participants included members from Apple, Google, IBM, Microsoft, Mozilla Foundation, Nokia and Opera.
"There is no doubt that HTML is a very important standard", the author of the first HTML version, W3C Director Tim Berners-Lee said, "I'm pleased to see the developer community, including browser vendors, working together to create the best development trajectory for the Web. Integrating the ideas of so many people is a difficult task, and we face The challenge is to find the balance between innovation and conservatism, idealism and pragmatism.”
HTML 5 will gradually replace HTML 4, but the finalization of HTML 5 specifications is still a long way to go. The current plan is to launch it in 2009 It was initially considered as a candidate for recommendation during the year, and was then implemented as the final official version in September 2010.
Author Charles Humble
Translator Zhang Yi