[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Fw: New Catalog XML Draft



----- Original Message -----
From: "Jeff de La Beaujardiere" <address@hidden>
To: "John Caron" <address@hidden>
Cc: <address@hidden>
Sent: Monday, May 20, 2002 8:51 PM
Subject: Re: Fw: New Catalog XML Draft


>
> # > Internal DTD rules override external DTD rules, but you can have both
in
> # > the same document. Internal DTD declarations come after the external
DTD
> # > call and between square brackets.
>
> The following clarification may not be relevant for your work, but
> just in case: The internal DTD is physically after the external DTD
> reference in the XML document, but the internal DTD is processed
> first. Strictly speaking, it does not override (i.e., redefine)
> external definitions but rather declares them first and thereby
> forbids the external DTD from declaring them. Therefore, you cannot
> use the internal DTD as a way to modify elements defined in the
> external DTD--you can only extend it by defining new elements.

I am still unclear: if the internal DTD declares an element, what happens if
the external DTD does also? If the second declaration gets ignored, isnt
that like overriding?

>
> The most error-prone part of the OGC Web Map Service metadata XML is
> the provision for vendor-specific elements via a required but usually
> empty %ENTITY declaration in the internal DTD. I have not yet
> determined whether XML Schema will let us do this more effectively.
>
> -Jeff DLB

Are you referring to this line in the Capabilities DTD? It seems very
similar to what Joe was trying to do. Were you trying to make a standard
list that could be extended? What was error-prone about it?

BTW, where is the "sample XML" mentioned below?

<!-- This WMT-wide list of possible output formats can be redefined by
individual servers; see the sample XML. -->

<!ENTITY % KnownFormats " GIF | JPEG | PNG | WebCGM | SVG | GML.1 | GML.2 |
GML.3 | WBMP | WMS_XML | MIME | INIMAGE | TIFF | GeoTIFF | PPM | BLANK " >



NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.