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Some comments:
1. Does ESIS output PIs in the DTD?
2. Entities in XML cannot have just a PUBLIC ID, they must also have a
SYSTEM id.
3. SDATA doesn't exist in XML. Do you mean NDATA?
-Wayne Steele
>From: Arjun Ray <aray@nyct.net>
>To: xml-dev@lists.xml.org
>Subject: Re: [xml-dev] "Datatypes" for DTDs
>Date: Wed, 02 Oct 2002 05:28:41 +0000
>
>Bob DuCharme <bobdc@snee.com> wrote:
>
>| All right, here's my trick for datatypes in DTDs [...]
>
>| To summarize: for simple element types, instead of the e-dtype
>| attribute used by DT4DTD, use a #FIXED xsi:type attribute described
>| in section 2.6.1 (http://www.w3.org/TR/xmlschema-1/#xsi_type) of XML
>| Schema Part 1, which is used more widely.
>
>Ugh. :-(
>
>| For attribute typing, I do have parameter entity trick, but I thought
>| it was better than the DT4DTD one.
>
>AFAIK, DT4DTD doesn't use PEs. This is one of its major virtues. (Maybe
>you meant that you like the trick itself better?) Personally, I view any
>method needing PEs to be basically broken.
>
>For completeness, let me outline one version of the external entity hack.
>Assume a declarative mechanism (say, a PI) which identifies the name of a
>distinguished attribute. For concreteness, let this name be type-map. It
>will have a declared value of NAMES (NMTOKENS in XML); the names will be
>of other attributes on the same element type. The first of these names
>will be that of an attribute with declared value ENTITIES, the rest of
>attributes for which data types will be "mapped" by the entities named in
>the first attribute (in a correspondence list fashion). These entities,
>in turn, are placeholder public identifiers with associated notations, and
>these notations name the data types. Putting it all together, you have
>something like this (using the example in the DT4DTD note):
>
> <?xml-typemap typemap ?>
> <!NOTATION date
> PUBLIC "etc etc"
> >
> <!ENTITY date-hook
> PUBLIC "whatever"
> SDATA date
> >
> <!NOTATION length
> PUBLIC "etc etc"
> >
> <!ENTITY length-hook
> PUBLIC "whatever"
> SDATA length
> >
> <!-- more like above, for all needed data types, and then -->
> <!ATTLIST person
> birthdate CDATA #IMPLIED
> binding CDATA #IMPLIED
> typemap NMTOKENS #FIXED "foo birthdate binding"
> foo ENTITIES #FIXED "date-hook length-hook"
> >
>
>Note that the typemap value will usually have one more name than the foo
>"hook" to datatypes. If the foo attribute has the same number, then the
>first is the hook for the element type itself. IOW, something like this
>
> <!ATTLIST birthdate
> typemap NMTOKENS #FIXED "foo"
> foo ENTITIES #FIXED "date-hook"
> >
>
>would mean that the data type applied to the #PCDATA content.
>
>Note that even something as "old-fashioned" as the ESIS output of nsgmls
>will report all the needed notations.
>
>A similar hack is possible with LPDs too.
>
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