Re: EMBED and validation

David G. Durand (dgd@cs.bu.edu)
Tue, 2 Dec 1997 23:00:29 -0500 (EST)


On Dec 1, 11:22am, Rob McDougall wrote:
> Subject: RE: EMBED and validation
> I'm new to XML but this doesn't seem to accomplish what I would be
> looking for as an "include" capability.

no, EMBED is _not_ an include facility. External text entities are.

> Let's say I have a markup language (let's call if RML, "Rob's Markup
> Language"). I create a DTD for it and post it to my public web site.
> All users of RML put the URL for the DTD in the <!DOCTYPE> declaration.
> So far so good?

yep.

> Now, if one particular user of RML notices that there's a section that's
> common across every one of their RML documents, they might wish to
> seperate it out into a distinct file and insert a link to it. This
> common piece is not a complete document unto itself so it cannot be
> validated, yet the user may wish to have the documents that include make
> sure that it is valid within the context that it was embedded. Since
> this particular file is unique to this user and not all RML users, it
> does not belong in the commono DTD. This would seem to make an external
> text entity undesireable for this case.

Right. That's why XML has the "internal subset. You put the any _per-document_
declarations there, (inside the square brackets of the doctype) and they
augment the DTD, without removing it.

> Is this correct, or am I missing something? Is there any other way to
> accomplish this using the current XML/XLL specs?

No; Yes; Yes.

for example, you might have:

<!doctype RML SYSTEM "some:URL/goes/here"
[
<!ENTITY boilerplate SYSTEM "http://Joes-server.isp.com/disclaimer">
]>

.... later on in your document ...
&boilerplate;

The entity reference to "boilerplate" will include the whole disclaimer without
having to change the DTD, or fill it with weird private information. Is this
good enough?

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David Durand dgd@cs.bu.edu| david@dynamicDiagrams.com
Boston University Computer Science | Dynamic Diagrams
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