Modularization ?

I'm a beginning student in XHTML (1.1) now, but I have significant experience in other, high-level programming languages, such as C and C++.

I would like to hear from PROGRAMMERS about the concept of modularization in XHTML 1.1 where a designer/programmer includes or excludes certain of the functional modules, based on the functionality of the program/product that is being developed.

Simply put, with C++ for example, you could obtain certain functionality for your program by linking to code libraries, but the addition of each one increased the size of your code.

Thinking, as I do, that these XHTML modules are nothing but DTD "references", what does it matter if a development author qualifies which modules of XHTML his product supports?

What is gained by editing a "standard" DTD in order to define the functionality that a given program or product supports, that is, if a hand-held widget did not make use of FRAMES functionality, what is the negative effect if the its referenced DTD includes the FRAMES module definition?

I really would appreciate any information that the programmers in this forum have about this issue.

Bill Luinetti

Two reasons not to include extra modules:

1) It makes the DTD bigger. This is only an issue when you're validating the xhtml file, but it's still an issue.

2) Using your example of a hand-held widget that doesn't handle frames: If I write an xhtml page for said widget, and I validate it against your DTD for said widget, and your DTD says my <frame> tags are perfectly valid, then I damn well expect you said widget to render my frames!!! . If it doesn't, it's broken.

This kind of comes down the purpose of a DTD. If an application only supports some of the tags in a DTD, what good is the DTD? You still have to look in other documentation somewhere else to find out how the app is going to render your page. In that case, you might as well define your DTD to include everything, or better yet just leave it out entirely.

Thanks, Bricker42;

Your response (2) was exactly what I needed...I had overlooked the obvious...the rest of the world would get an incorrect reading from me, if my hand-held widget DTD was just a plain, vanilla standard.

I thank you, sincerely, for your time.

Bill Luinetti