What is extensible about xhtml?

[think2]

The x in xhtml stands for extensible. Why is xhtml extensible and html is not? What exactly is extensible in xhtml?

Has the extensibility (whatever that is) of xhtml been made use of anywhere?

TIA

 

[Ken g6]

The tags are extensible. You can define practically any tag you want with a schema. Or just ignore the schema thing and parse it with Perl regexes like I do. (This is a bad habit of mine. It's almost always better to at least parse it as markup, as opposed to line-by-line.)

Edit: I misread xhtml as xml. :$

 

[think2]

You can add extra tags to html can't you?

Why do you add extra tags? What do you do with them? Why do you parse xhtml and why with perl?

 

[PhatoseAlpha]

Depends on how you look at it. XHTML is a subset of XML, and thus XML itself is an extension of XHTML from a certain point of view. However, I doubt that's what you meant.


XHTML was extensible in that it is supposed to be fair game to create your own new tags as long as you point it to an appropriate doctype declaration. So, theoretically in XHTML I could create a new tag like <DIMENSIONSPECIFICATIONS>1x4</DIMENSIONSPECIFICATIONS> and have it be perfectly valid and correct XHTML. You can't do that in HTML - you're stuck with whatever tags W3C gives you.

That's all theoretical though. Between the poor browser support for doing that, the extra overhead of making your own doctypes, and the simple reality that you can pretty much always achieve the same effect with classes, nobody actually does that.

 

[think2]

I still don't really get it. I have a suspicion that the X in XHTML should stand for XML-conforming, not extensible.

XHTML was extensible in that it is supposed to be fair game to create your own new tags as long as you point it to an appropriate doctype declaration.

Can you create new tags in HTML? I thought that's what Microsoft does and is the means by which html develops?

Do browsers actually look up the doctype declaration when they process xhtml and do they reject non-conforming pages?

 

[Markbnj]

Can you create new tags in HTML? I thought that's what Microsoft does and is the means by which html develops?

HTML is a standard. What Microsoft and other companies/orgs have done is to create proprietary tags that are parsed on the server-side before being sent to the browser. I don't recall whether they have created client-side proprietary tags, but if they did then only their browser would recognize those tags, which would be bad.

 

[think2]

HTML is a standard. What Microsoft and other companies/orgs have done is to create proprietary tags that are parsed on the server-side before being sent to the browser. I don't recall whether they have created client-side proprietary tags, but if they did then only their browser would recognize those tags, which would be bad.

But this happens with xhtml too.

What is the point of having proprietary tags processed by the server? That requires a proprietary server? What are these proprietary tags for? Have they been made public - if not, they can't really be called proprietary.

 

[Aluvus]

I still don't really get it. I have a suspicion that the X in XHTML should stand for XML-conforming, not extensible.

Perhaps, but the acronym is already clumsy enough.

Can you create new tags in HTML? I thought that's what Microsoft does and is the means by which html develops?

In HTML, browsers will accept tags they don't understand, but they won't really do anything with them (except what CSS tells them to); they can't really be made to "know" what the tags mean.

Do browsers actually look up the doctype declaration when they process xhtml and do they reject non-conforming pages?

Per the spec, yes; in practice, not always.