XHTML..
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
XHTML is a combination of HTML and XML (EXtensible Markup Language)
XHTML consists of all the elements in HTML 4.01 combined with the syntax of XML
XHTML 1.0 became a W3C recommendation back in January 26, 2000.
W3C defines XHTML as the latest version of HTML.
XHTML will gradually replace HTML.
All New Browsers Support XHTML
XHTML is compatible with HTML 4.01.
XHTML is a reformulation of HTML 4.01 in XML, and can be put to immediate use with existing browsers by following a few simple guidelines.
You should start to write your HTML code in lowercase letters, and NEVER skip ending tags from now on.
Why should you use XHTML?
XML is a markup language where everything has to be marked up correctly, which results in very well formed documents.
XML was designed to DESCRIBE data, and HTML was designed to DISPLAY data.
With many different browser technologies, some run Internet on computers, some run Internet on mobile phones and hand helds; the latest do not have the resources to interpret a "bad" markup language.
Therefore, by combining HTML and XML, and their strengths, you've got a markup language that is useful now and in the future, and it is called XHTML.
XHTML pages can be read by all XML enabled devices.
The syntax of XHTML
XHTML elements must be properly nested
XHTML elements must always be closed
XHTML empty elements must also be closed
XHTML elements must be in lowercase
XHTML documents must have one root element
XHTML attribute names must be in lower case
XHTML attribute values must be quoted
XHTML attribute minimization is forbidden
XHTML id attribute replaces the name attribute
HTML 4.01 defines a name attribute for the elements a, applet, frame, iframe, img, and map.
In XHTML the name attribute is deprecated. Use id instead.
To interoperate with older browsers for a while, you should use both name and id, with identical attribute values.
XHTML DTD (Document Type Definitions) defines mandatory elements
An XHTML document consists of three main parts:
1. The DOCTYPE (Mandatory)
The DOCTYPE declaration should always be the first line in an XHTML document.
The DOCTYPE declaration is not a part of the XHTML document itself. It is not an XHTML element, and it should not have a closing tag.
2. The Head
3. The Body
There are 3 XHTML document types:
STRICT:
Use STRICT when you want really clean markup, free of presentational clutter. Use this together with Cascading Style Sheets.
TRANSITIONAL:
Use TRANSITIONAL when you need to take advantage of HTML's presentational features and when you want to support browsers that don't understand Cascading Style Sheets.
FRAMESET:
Use FRAMESET when you want to use HTML Frames to partition the browser window into two or more frames.
To make your XHTML compatible with today's browsers, you should add an extra space before the "/" symbol.
The html, head and body elements must be present, and the title must be present inside the head element.
The xmlns attribute inside the <html> tag is required in XHTML.
However, the validator on w3.org does not complain when this attribute is missing in an XHTML document.
This is because "xmlns=http://www.w3.org/1999/xhtml" is a fixed value and will be added to the <html> tag even if you do not include it.
How can I include flash in valid (X)HTML Web pages?
There are many techniques to incorporate flash in valid web pages.
One of the most famous is the "Flash Satay" technique created by Drew McLellan
The following is a short version of it, but if you want to read about Mr. McLellan complete development process, please by all means, go and visit his web site, it's a great read.
Many Flash authoring tools recommend, or enforce, the usage of the <embed> element to include flash animations or applications in Web pages.
<embed>, however, was never part of any standardized version of HTML, and this practice produces invalid markup..
.. Originally created by Netscape as their method of embedding plug ins and players in web pages, and while some browsers other than Netscape support it...
.. It’s not standards-compliant, so it’s out!
<object> is part of the XHTML specification, but is badly implemented in this case.
It is used by IE style browsers to start an instance of the Flash Player and load in the specified movie.
The <param> element is its bedfellow, offering any number of parameters to be passed to the player once it is started.
The Flash Player is configured to respond to content with a MIME type of application/x-shockwave-flash.
This is great, because the type attribute allows to specify a content type.
Therefore, out goes... classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
... and in comes... type="application/x-shockwave-flash"
Next comes the "codebase" attribute...
...Well the "codebase" attribute has got to go too...
... And here comes the "data" attribute...
... Not quite enough for I.E though... (not streaming the movie)
The Satay Method
"Creating a very small container movie, which in the first frame loads in the real movie we want to play!"
As Mr. McLellan says: "It’s a bit of a hack, but a valid and justifiable hack in my opinion." (we kind of agree)...
"The greatest thing is that you don’t have to create a separate container movie for each “real” movie...
...
ONE smart container can work with any Flash movie having the same proportions.
No matter if your movie is made from beef, chicken, or pork, you still need to skewer it and dip it in the sauce to make it work...
We call this the Satay Method."
Mr. Drew McLellan's container movie...
"I created a new Flash movie and put the following ActionScript on Frame 1 right in the root of the movie:
_root.loadMovie(_root.path,0);
This instructs the Flash Player to load a movie, whose name is in the variable path on the root, into Level 0 of the current movie.
All we need to do is make sure that the name of the movie we want to load is held in the variable called path.
Flash makes this part easy. The Flash Player loads any name/value pairs that are passed to a Flash movie on a query string into the root of the movie.
This is useful for many different applications, but in our case it means that we just need to call the movie like this:
c.swf?path=movie.swf
The container movie is c.swf.
I’m passing it a variable called path with a value of movie.swf.
This means that our ActionScript, when evaluated, would equate to this:
_root.loadMovie("movie.swf",0);
You can modify the behavior of the container movie to do whatever you like, as long as it’s kept small.
You can use GET and POST to pass variables through the container if you need to,
for example.
This method, however, will only work well if the container movie is just a few kilobytes in size.
The markup:
<object type="application/x-shockwave-flash"
data="c.swf?path=movie.swf"
width="400" height="300">
<param name="movie"
value="c.swf?path=movie.swf" />
</object>
Compensating the loss of the "codebase" attribute...
"The workaround is simple: just include one sacrificial movie at the front of your site with the codebase attribute left in.
This needs to be a movie with no purpose within the site...
just a 1k empty blob of nothingness that causes the user to be prompted if they have an old version of the plug in.
Not the cleanest approach, but a practical one. It shouldn’t lose you any friends."
FINAL?
<object type="application/x-shockwave-flash
data="c.swf?path=movie.swf"
width="400" height="300">
<param name="movie"
value="c.swf?path=movie.swf" />
<img src="noflash.gif"
width="200" height="100" alt="" />
</object>
"If the browser doesn’t know how to play objects with a MIME type of application/x-shockwave-flash,
it will simply go for the next child element and give that a try.
I’m guessing that a simple image element should be okay for most people.
Failing that, you can simply use text."
Work in progress (Mr. Drew McLellan's conclusion)
"I’ve written this article with the knowledge that it’s simply one man’s findings and thus a work in progress.
Consider it like a scientific theory: what I state today is only proven until it’s disproved."
About the Author
 Drew McLellan is the author of Dreamweaver MX Web Development and a member of The Web Standards Project’s Dreamweaver Task Force, who work with Macromedia to improve standards compliance in its market-leading web authoring products.
XHTML validation
Introduction to TIDY
When editing HTML it's easy to make mistakes. Wouldn't it be nice if there was a simple way to fix these mistakes automatically and tidy up sloppy editing into nicely layed out markup? Well now there is! Dave Raggett's HTML TIDY is a free utility for doing just that. It also works great on the atrociously hard to read markup generated by specialized HTML editors and conversion tools, and can help you identify where you need to pay further attention on making your pages more accessible to people with disabilities.
Clean up your Web pages
with HTML TIDY
HTML validators
Page Walet
WDG's HTML Validator
|
