Still not fixed in Daffodil version 3.2.1
Bummer.
/Roger
From: Roger L Costello <coste...@mitre.org>
Sent: Thursday, December 2, 2021 8:00 AM
To: users@daffodil.apache.org
Subject: Re: Huh? Nillable complex type elements can only have '%ES;' as their
dfdl:nilValue property
Hi Mike,
1. Would you get the DFDL committee to remove this restriction, please?
2. I have 350 data formats, each having dozens of fields with nillable
complexTypes. So there is a strong use case for removing the restriction.
3. The choice idea that you presented, although clever and interesting, is not
suitable. In the example I presented, the output XML should be one of these:
<MyField>-</MyField>
<MyField>
<DateTimeIso>…</DateTimeIso>
</MyField>
<MyField>
<MonthName>…</MonthName>
</MyField>
With the technique you showed, the output would be one of these:
<noValue>-</noValue>
<MyField>
<DateTimeIso>…</DateTimeIso>
</MyField>
<MyField>
<MonthName>…</MonthName>
</MyField>
That first one -- <noValue> -- is not unacceptable to my community.
/Roger
From: Mike Beckerle <mbecke...@apache.org<mailto:mbecke...@apache.org>>
Sent: Wednesday, December 1, 2021 4:06 PM
To: users@daffodil.apache.org<mailto:users@daffodil.apache.org>
Subject: [EXT] Re: Huh? Nillable complex type elements can only have '%ES;' as
their dfdl:nilValue property
This is definitely a DFDL language restriction, not a Daffodil-specific thing.
I have made inquiries as to what the rationale is for this restriction, and
I'll report back.
In the mean time, maybe this sort of technique.
<choice>
<element name="noValue" type="xs:string" dfdl:lengthKind="explicit"
dfdl:length="0" dfdl:initiator="-"/>
<element name="myComplexType">
.... non nillable complex type definition ....
</element>
</choice>
I have to admit that this workaround sort of suggests that there isn't a
coherent rationale for the restriction, as this is pretty obviously equivalent
to the complex type being nillable with nilValue="-".
On Wed, Dec 1, 2021 at 12:43 PM Roger L Costello
<coste...@mitre.org<mailto:coste...@mitre.org>> wrote:
Hi Folks,
I am creating a DFDL schema for a data format that has a field whose value is a
hyphen when no data is available and when data is available, then the field
contains either an ISO datetime or a 3-letter month name. Here's how I
specified the field:
<xs:element name="MyField" nillable="true" dfdl:nilValue="-">
<xs:complexType>
<xs:choice dfdl:choiceLengthKind="implicit">
<xs:element name="DateTimeIso">
<xs:complexType>
<xs:sequence>
...
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="MonthName" type="xs:string"
dfdl:length="3" dfdl:lengthKind="explicit" />
</xs:choice>
</xs:complexType>
</xs:element>
When I run it, Daffodil gives this error message:
[error] Schema Definition Error: Nillable complex type elements can only have
'%ES;' as their dfdl:nilValue property.
Is that an error in Daffodil? Or, is it an actual DFDL restriction? If the
latter, why is there such a restriction? How do I work around this error?
/Roger
