[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

DTD Entity

• From: Richard Knapp <warped_user@y...>
• To: "xml-dev@l..." <xml-dev@l...>
• Date: Sat, 10 Mar 2001 09:29:34 -0500 (EST)

Since it isn't quite dead yet (just mortally wouned), I have a question DTD Elements.

Note: Beginner's question is being posed. Please excuse any cases of gross lack of knowledge.

We are working on DTD with the following requirement:

- Base element consists of Child elements First, Second, Third, and Fourth.
- First must appear under Base.
- Second, Third, and Fourth may appear zero or one time.
- Order is not important for elements Second, Third, and Fourth.

The original statement in my DTD was

<!ELEMENT Base (First, Second?, Third?, Fourth?)>

Which imposes an order constraint on the elements. It was suggested that

<!ELEMENT Base (First (Second|Third|Fourth)?)>

was more correct. However, this appears it will allow only Second, Third, _or_ Fourth element, not all three. Is 
this correct?

Conversely:

<!ELEMENT Base (First (Second|Third|Fourth)*)>

seems to allow enough elements (zero or one of each) but also allows more than one.

Is there a good way to address this situation or is this a limit of DTDs? Do Schemas handle this any better?

Again, thank you for you patience.

	- Richard



_________________________________________________________

Do You Yahoo!?

Get your free @yahoo.com address at http://mail.yahoo.com

• Follow-Ups:
  • Re: DTD Entity
    • From: Charles Reitzel <creitzel@m...>

• Prev by Date: Re: XML Schema built-in data type namespace URI
• Next by Date: 100's of old Posts Today
• Previous by thread: Looking for help with MSXML CAB
• Next by thread: Re: DTD Entity
• Index(es):
  • Date
  • Thread