tailieunhanh - HTML cơ bản - p 29

264 Chapter 5: Building Websites noticeable in the preview from messing up the blog’s front page. This can happen, for example, when a link at the end of a post is missing the closing anchor tag (). When reproduced on the front page, the link may extend into the title of the post below it in the listing. n ot t e S t i n g i n D i F F e r e n t B r oW S e r S Browsers are getting better all the time and are converging on HTML5 as a common standard. But many of. | 264 Chapter 5 Building Websites noticeable in the preview from messing up the blog s front page. This can happen for example when a link at the end of a post is missing the closing anchor tag a . When reproduced on the front page the link may extend into the title of the post below it in the listing. NOT TESTING IN DIFFERENT BROWSERS Browsers are getting better all the time and are converging on HTML5 as a common standard. But many of the HTML5 specifications for browser behavior are recommendations not requirements. Also a wider variety of browsers are in use across more device types and operating systems than ever before. Furthermore browsers are getting bigger and incorporating more features. As a consequence of all this complexity there are bugs and edge conditions where browser behavior is not well defined. Therefore there is no way to ensure that your web pages will perform flawlessly without testing them in all the major browsers. It is human nature to become attached to your favorite tools. When other people encounter problems with your website it s tempting to blame their poor choice of browser. Avoid falling into this unproductive attitude by making it a point to use different browsers as you work on your website. Testing in Internet Explorer Firefox Chrome Safari and Opera covers about 98 percent of all browser use according to data collected on Wikipedia. Search for browser share to find the latest statistics. Unfortunately that also means testing on older versions of Internet Explorer. Currently Internet Explorer version 6 running on Windows XP NT 2000 and earlier versions of Microsoft s operating systems still accounts for a fifth of all browser usage This is in spite of the fact that this browser is ten years old and is widely derided for its security issues and lack of support for modern web standards. It is a persistent fact that many people are forced to work with the tools they are given not the ones they would prefer. Major web service companies