Hi friends,

Can any one tell me What is XHTML?


Thanks
devarajan.V

Is simple words, XHTML, or Extensible HTML, is HTML 4 with XML rules applied to it (each begin tag must have an end tag, attribute values in single/double quotes, etc.). However, the overall vision of XHTML is much more than that. In addition to using XML syntax for HTML, XHTML also encloses specifications such as XHTML Basic (minimal set of modules for devices such as PDAs), XForms (represents the next generation of forms for the Web, and separates presentation, logic, and data), XML Events (provides XML languages with the ability to uniformly integrate event listeners and associated event handlers), etc.

hi,

I have given an elaborate information about XHTML


The evolution of HTML has essentially stopped. Instead, HTML is being replaced by a new language, called XHTML. XHTML is in many ways similar to HTML, but is designed to work with the new eXtensible Markup Language, or XML, that will soon serve as the core language for designing all sorts of new Web applications, in which XHTML will be only one of many "languages." But, XHTML is designed to work with these other language, so that different documents, in different languages, can be easily mixed together.

For this to work, the rules for writing HTML documents had to change. These rules are simple, and are as follows:

1. All tag and attribute names must be in lowercase. Thus, you can't write
<A HREF="foo.html">...</A>
but must instead write this in lowercase, as :
<a href="foo.html">...</a>

2. "Empty" tags must be written with an extra slash at the end. An empty tag is one like <br> or <img src="foo.html"> that doesn't have a </br> or <img> to end it. In XHTML, such tags must be written as: <br />, and <img src="foo.gif" />.

3. You can never omit an end tag. With HTML, you could sometimes leave off an end tag, as in
<p> ..... paragraph text
<p> ..... more paragraph text
With XHTML, you must always put in the end tag, so that the preceding must be written as:
<p> ..... paragraph text </p>
<p> ..... more paragraph text </p>

4. Attributes must always have a value. In HTML you can sometimes omit atttibute values, as in
<hr size="2" noshade>
in XHTML, this would need to be written as:
<hr size="2" noshade="noshade" />

5. Attributes values must always be quoted.. In HTML you can sometimes omit the quotes,as in
<hr size=2>
in XHTML, this would need to be written as:
<hr size="2" />

That's about it -- there are a few more subtle details, but essentially if you follow the above rules, then the documents you write are acceptable as XHTML. Thus it's easy to write up Web pages using the XHTML format -- they will work with today's HTML browsers, and are easily upward-compatible for the next-generation of Web browsers.

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Venkat
knowledge is Power

Short for Extensible Hypertext Markup Language, a hybrid between HTML and XML specifically designed for Net device displays.

XHTML is a markup language written in XML; therefore, it is an XML application.

XHTML uses three XML namespaces (used to qualify element and attributes names by associating them with namespaces identified by URI references. namespaces prevent identically custom-named tags that may be used in different XML documents from being read the same way), which correspond to three HTML 4.0 DTDs: Strict, Transitional, and Frameset.

XHTML markup must conform to the markup standards defined in a HTML DTD.

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S.VinothkumaR
Behind me is infinite power,
Before me is Endless Possibility,
Around me is Boundless Opportunity,
Why should I fear!

XHTML is a stricter form of HTML and as such is a subset of XML which is an extremely useful, powerful and very strict way of marking up pure data.

The headers you sometimes see along with XHTML code declare what exactly the rules are.. for instance, that <a> is an anchor. In XML you can declare your own rules.

XHTML is significantly better than HTML, as it encourages good practice. Where it doesn't allow things that HTML does, it's likely there's a good reason.. for instance not using target="_blank". These things then in turn impact on the sites accessibility, consistency, search engine performance etc etc.

XHTML (eXtensible HyperText Markup Language) is the W3C's new version of HTML. It is the reformulation of HTML 4.0 as an application of XML, containing a family of current and future document types and modules that reproduce and extend the capabilities of HTML. XHTML provides the framework for future extensions of HTML, with the aim of replacing HTML in the future.

• XHTML stands for EXtensible HyperText Markup Language
• XHTML is aimed to replace HTML
• XHTML is almost identical to HTML 4.01
• XHTML is a stricter and cleaner version of HTML
• XHTML is HTML defined as an XML application
• XHTML is a W3C Recommendation

difference between html & xhtml is :-

xhtml element must always be closed .
empty element must also be closed.
xhtml element must be in lower.
xhtml must have one root element.

The difference is only seen by the people creating the pages (Web designers, programmers, etc.) and focuses on “forgivability”— HTML allows for some ugly code (mixed-case tags like <BoDy>, improperly nested elements, and unclosed tags), while XHTML does not. If you write HTML, it’s probably a good idea to start using XHTML practices anyway.

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J. Jeyaseelan
Everything Possible

Example of valid HTML:
<p>This is a paragraph

Equivalent in XHTML:
<p>This is a paragraph</p>

Tags that don’t contain data (like breaks, images, and horizontal rules) should also be closed in HTML. There’s no need to write an opening and closing tag, though. We can use the perfectly acceptable shortcut:

<!— Examples of properly closed XHTML tags -->
<!—Properly closed image -->
<img src=”someimage.gif” alt="An image" />
<!—Properly closed break tag -->
<br />
<!—Properly closed horizontal rule -->
<hr />

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J. Jeyaseelan
Everything Possible

In HTML, the following code might display exactly as you intended:

<strong><em>Here’s some bold and italicized text</strong></em>

Although this might work, it’s not “good” code. And for the purposes of this article, not valid XHTML either. To complete your XHTML training, simply make sure your tags are properly nested:

<strong><em>Here’s a valid XHTML version of bold italicized code</em></strong>

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J. Jeyaseelan
Everything Possible