I'm trying to constrain the 'role' attr to be one of two values.
Initially, I'm doing this on the <phrase> element, but eventually I want
to do this on all elements.
This is in DocBook 5, and I'm using the non-compact RNG syntax for our
customization. There's an example in Walsh and Muellner's "DocBook 5.0"
document in section 5.10, but it's in the compact syntax:
namespace db = "http://docbook.org/ns/docbook";
include "docbook.rnc" {
db.procedure.role.attribute = attribute role
{ "required" | "optional" }
}
OK, I thought, can't be too hard...
Several hours later, and a good deal of searching on the web, I still
can't get it to work. My non-compact syntax schema fragment looks like
this (omitting the 'include docbook.rng' part):
<define name="db.phrase.role.attribute" >
<attribute name="role">
<choice>
<value type="string">tech</value>
<value type="string">nontechy</value>
</choice>
</attribute>
</define>
(The funny spelling of "nontechy" here is intentional: the value in the
document is actually "nontech", so what I'm trying to do is to ensure
that this customization signals a warning for any 'role' attrs in the
text whose values don't match the above schema fragment.)
Using the above code, XMLmind signals an error about the customization:
multiple definitions of "db.phrase.role.attribute"
without "combine" attribute
I'm not sure how the "combine" attr is supposed to be represented in the
compact syntax, but clearly it's required in the non-compact syntax.
However, I have tried both possible values of this attr, without success.
Specifically, if I add 'combine="interleave"', to the <define...> tag,
then I get the error
duplicate attribute "role"
If I instead add 'combine="choice"' I don't get an error, but I do get
some odd behavior. For existing <phrase role="nontech"> tags, there is
no warning, despite the fact that this spelling does not conform to the
above schema. If I create a *new* <phrase> tag, the attributes pane in
XXE shows me two role attributes: one is just 'role', and appears to be
text-valued (that is, it simply allows typing in a value); the other is
labeled 'role-2', and has a drop-down with the above two values ('tech'
and 'nontechy'). (Sometimes 'role' and 'role-2' are reversed, I'm not
sure when this happens.) Neither behavior is what I want: I want it to
flag existing 'nontech' roles as warnings (because they're misspelled
according to the above schema fragment); and for new <phrase> tags, I
want just a 'role' attr (with two choices), not a 'role' attr and a
'role-2' attr.
Do you have some sample schema code in which an attr which is defined in
DocBook 5 as text-valued (like 'role') is customized to allow only one
of an enumerated set of values?
--
Mike Maxwell
What good is a universe without somebody around to look at it?
--Robert Dicke, Princeton physicist
