More flexible DTD solution needed

[Collin VanDyck]

Hello!

I'm relatively new to writing DTDs, so be gentle with me

I'm writing a DTD to validate XML documents that script my product which
managed XHTML.

I want to use the DTD to enforce basic, high level structure but I don't
want to account for every single type of element that could be in the
script document.

For instance, I want to allow this:

<script>
<add-page>
<name>testPage</name>
<content>
ALL SORTS OF XHTML CONTENT GOES HERE
</content>
</add-page>
</script>

In my DTD I specify the rules for the script, add-page, name, and
content elements. However, I want to allow all sorts of markup in the
content element without having to account for it in the DTD.

In other words, if the user supplies:

<script>
<add-page>
<name>testPage</name>
<content>
<b>Hi!</b>
</content>
</add-page>
</script>

Then I get an error when validating because 'b' was not defined as an
element.

Any ideas, or is this not possible using DTD ?

thanks,
Collin

 

[Peter Flynn]

Hello!

I'm relatively new to writing DTDs, so be gentle with me

I'm writing a DTD to validate XML documents that script my product which
managed XHTML.

I want to use the DTD to enforce basic, high level structure but I don't
want to account for every single type of element that could be in the
script document.

You can't. Validation means accounting for every single element.

For instance, I want to allow this:

<script>
<add-page>
<name>testPage</name>
<content>
ALL SORTS OF XHTML CONTENT GOES HERE
</content>
</add-page>
</script>

That's different. Depending on what you really mean, you could either

a) write a DTD which allowed XHTML mixed content, equivalent to the
content model for P, for example

b) write a DTD which allowed any arbitrary mix of XHTML element types
(so it would never actually be valid XHTML in there, just a jumble.

(a) is easy. (b) is not so easy, because you still have to declare the
element types and provide them with content models.

Any ideas, or is this not possible using DTD ?

You either want valid XML or you don't. If you want it valid, it has to
conform to a DTD or Schema, so you have to write one which it can be
validated against. If you don't want to do that, you can't have valid
XML, just well-formed XML. Your call.

///Peter

 

[Richard Tobin]

Any ideas, or is this not possible using DTD ?

Right, it's not possible.

It can be done with XML Schemas though.

-- Richard

 

[Tommaso Torti]

Right, it's not possible.

It can be done with XML Schemas though.

-- Richard

Richard, can you explain this point with more details ?
Please... ;-)

Tommaso

 

[Richard Tobin]

It can be done with XML Schemas though.

[/QUOTE]

Richard, can you explain this point with more details ?

XML Schemas allow you to use a "wildcard" that matches any element,
and you can specify whether the subtree rooted at that element should
be validated.

For an introduction to XML Schemas see

http://www.w3.org/TR/xmlschema-0/

-- Richard