tailieunhanh - Sams Teach Yourself CSS in 24 Hours- P10

Sams Teach Yourself CSS in 24 Hours- P10: Times have changed, thankfully, since those Dark Ages of CSS. All major browsers as well as some minor ones have increased support for Cascading Style Sheets in the latest versions. Web developers are aware of CSS and the vital role they play in designing great Web pages, and presumably you’ve got some idea of how important they are if you’ve bought this book. | 432 Hour 24 Listing Continued author name Kynn Bartlett name email lt kynn@ gt email author tipbody para When a blind user accesses a Web page using a screenreader the screenreader uses a specific language dictionary to know how words should be pronounced based on the language of the page. If the wrong dictionary is used the speech will be very difficult to understand. para para If the language changes in the middle of the Web page you need to mark that change with the code lang code attribute which can be set on any HTML tag but is usually set on the code lt span gt code element. This will let the screenreader know which language dictionary to use when synthesizing speech. para para paratype note The XML equivalent of the code lang code attribute is code xml lang code . para tipbody tipexample lt p gt lt span lang de gt Ich bin Berliner. lt span gt I am a resident of Berlin lt p gt tipexample accesstip tippage Notice that in the listing the tipexample element contains HTML code but the angle brackets have been converted to character entities using lt and gt . Also notice that this document says absolutely nothing about how to display the content it just defines the information and leaves it at that. This is one of the primary uses of XML completely separating presentation from content. Later this hour you ll see how CSS can be used to define that presentation. CSS and XML 433 DTDs and Schemas To make the jump from an XML document to an XML-based language you need to have a formal definition for a language. An XML document is not required to be part of an XMLbased language though An XML document without a formal definition basically creates an ad hoc language as it goes along and by the rules of XML that s perfectly valid. However if you re writing an application that you mean for others to use you may need to have the syntax of your XML document written down. There are two primary ways to do this XML Document Type Definitions DTDs and XML Schemas.