|
XHTML - What is it?
XHTML stands for EXtensible HyperText Markup Language - Extended Hypertext Markup Language. The language is designed to replace сущETS is widely used today, and HTML. According to the new syntax of the language is virtually identical to HTML. It is more structured and «clean» version of HTML. Furthermore, XHTML is in the form of XML-applications.
Since January 2000, XHTML versions 1.0 officially recommended by W3C consortium as a new web standard. W3C XHTML announced the latest version of HTML, and predicted the gradual replacement of the old to new.
With regard to support for the new standard - all modern browsers supportedare XHTML.
The new language is a synthesis of the usual HTML and XML, and is composed of the elements of HTML 4.01 in combination with syntax XML.
Background and motive of the new standard are obvious. At one point, came to that Webhave that many Web pages have the «wrong» HTML, poor-quality markings. Despite the fact that the page looks fine, its code is not formed in accordance with standard HTML - as in the following example:
<html>
<head>
<title> Incorrect markup </ title>
<body>
<h1> Bad HTML
</ html>
In this example, there is no end tag </ head> before opening <body>; missing closing tag header </ h1>. & Nbsp;
Here is a quite common error:
<b> <I> Text </ b> </ I>
According to the tags must be closed in the reverse order of their discovery.
XML - a markup language where everything has to be formed correctly, but in this case, the data will be displayed. Otherwise, there is a mistake. If the XML is designed to describe data and HTML - for their display, the XHTML successfully combined the advantages of educationtheir languages.
In today's world, the various IT technologies browsers. Some of them work on a PC, some - on mobile phones, smartphones and PDAs. And the latter are not so many resources on the interpretation and understanding of & laquo; bad »HTML. It is here that there is a need for new language, which became XHTML. It should say that XHTML-pages will be able to display any device that supports XML. The new language - this is a ticket to the future. While the digital world improved to support XML browsers have developedtchikov have time and opportunity to create the correct documents to be available to all new browsers - to continue, not least, kept going.
Okay, and what web developers do not have to pereuchivatsya. It is necessary only to understand some features of languageand remember the principles of the documents:
1. Elements of the document should be clearly embedded and subordination. When we first opened up the title tag, then tag italic, after the text, we must first close the italics tag for them - the title tag.
2. Documents must be properly formed. Root elements for the remaining elements of the document is a tag <html>.
3. The names of the tags must be in lower case.
4. All tags must behave the closing tags. Please note that the opening tag with no closing tag (<img>, <br>, <hr> etc.) should be shut themselves (<img />, <br />, <hr />). And to quote (/
Writing a correct code involves the use of explicit syntax:
- Attribute names must be in lower case (<font color = "red" >);
- Attribute values must be in quotes (<font color="red">);
- Somewhat unusual requirement prohibition minimize attributes. If before we can write <input type = "checkbox"Checked>, now this record should look like this: <input type="checkbox" checked="checked">;
- Attribute name is replaced with the final attribute id. If now these attributes priravnivayutsI, the future will only id;
- In the first line of the document should be a fundamental element in DOCTYPE, telling the browser type of the document: <! DOCTYPE type>. It should be noted that the DOCTYPE element is not part of XHTML-document, so should not haveclosing (closed by themselves);
- HHTML document can be of three types (the definition of Document Type Definitions). In general, the document consists of three main parts: DOCTYPE, Head and Body:
<! DOCTYPE ...>
; <html>
<head>
<title> ... </ title>
</ head>
<body> ... </ body>
& nbsp; </ html>
Document type can be STRICT, TRANSITIONAL or FRAMESET. The most common is the second type.
Strict type is used in the provision of clean markup, free of visual processing. Can be used in conjunction with CSS (cascading style sheets).
Transitional type is used, if necessary, visuallyOn submission, plus support for browsers that do not use CSS (the most common type).
Frameset type is used for frames.
|