HTML5, rumored to be the killer of Flash, is a revolutionary network technology for web application development. HTML 5 provides some new elements and attributes, some of which are technically similar to the and tags, but have certain meanings, such as and . Such tags will facilitate search engine indexing, use on small screen devices and the visually impaired. It also provides new functionality for other browsing elements, such as the and tags, through a standard interface. In addition to the original DOM interface, HTML5 adds more diverse APIs: Real-time 2D drawing Canvas API: API for dynamically generating and rendering graphics, charts, images and animations. Scheduled media playback HTML5 audio and video: New elements in HTML5, which provide developers with a set of common, integrated, script-based APIs for processing audio and video without installing any plug-ins. Offline storage database (offline web application) Edit Drag and drop Cross-document communication Communication/Network Communication APIs: Two foundations for building real-time and cross-origin communication: Cross Document Messaging and XMLHttpRequest Level 2. Browsing history management MIME and protocol handler header registration Microdata The above technical descriptions exist in the WHATWG HTML documentation, but not all of them are included in the W3C HTML5 documentation. W3C has separately explained some technologies, and this article will not go into details one by one. It sounds a little too technical, so what impact will HTML5 have on design? This is a question that web designers and developers have to consider after taking the trouble to discuss programming code. Advantages of HTML5 and web app Take the mobile Internet field as an example. Faced with numerous terminal devices and platforms, designers and developers have to make compromises in terms of product presentation and experience consistency, and are tired of filling the platform. So much of our energy was wasted. The product could have reached a higher level, but the reality of mobile terminal fragmentation (including hardware and software) blocked the good wishes. The current mainstream mobile phone development platforms include: iOS, Symbian, Linux, Palm, BlackBerry, Windows Mobile, Android, etc. Among them, the iOS platform needs to be designed separately for the resolutions of 480*320, 960*640 and 1024*768; the QVGA resolution on the Android platform is 240*320, the WQVGA resolution is 240*400, and the HVGA resolution is 320*480. The WVGA resolution is 480*800, the FWVGA resolution is 480*854, etc.; the Symbian system has a long history. It is currently developed mainly for the S60 V3 and V5 versions, and the resolutions are still 176*208, 208*208, 240* 320/320*240, 352*416/416*352 and 800*352 and many other types. Even for the same platform, designs with different resolutions will have corresponding differences. In addition, client products need to be constantly updated and iterated, from version 1.0, version 2.0 to version N.0; every time a native app is developed, a platform needs to be laid. And the reality is that not all users will actively update the new version, so designers and developers have to worry about whether the previous old version will support it when developing new features. Different platforms are multiplied by different versions, manpower and material resources are invested in the work of laying the platform, and the energy to improve the user experience of the product is relatively limited. So people were fed up with the fragmentation of terminal devices and began to look forward to the emergence of something different from native apps. The emergence of web apps developed by HTML5 technology has given designers and developers a bright future. The rendering process of HTML5 technology is mainly performed by browsers, applications with embedded HTML5 parsers, applications that support bookmark opening, or mobile phone products. In this way, product launches and version updates no longer need to take so long to build the platform. Appcelerator's internal logic will convert the product's UI into the native interface of platforms such as iOS or Android. At the same time, products in the form of web apps do not require users to download updates, and the latest version can be accessed through the network; it also facilitates designers and developers to debug and correct errors, and there is no longer the problem of taking into account both old and new versions.
