So I think your requirements are this:
* fixed length 5
* the hyphen nil indicator may have spaces around it
* canonical form is left justified for "-" or any value.
This is the best I could do. I had to surround the nillable element with
another element so as to get left-justification by way of filling of the
unused region of a complex type, with fillByte which is %SP;.
If you want center justified hyphens for the nil case and left-justified
strings for the value case, then I think it's not possible to model this
without using separate elements for the nil and value. (That solution not
shown here.)
<element name="Foo"
dfdl:length="5"
dfdl:lengthKind="explicit"
dfdl:terminator="/"
dfdl:fillByte="%SP;">
<!--
The above achieves canonical unparse
as left-justified fixed length because
the fillByte will be used to fill unused
space on the right.
This only works for fixed length left-justified data.
If this was right-justified, this trick would not work.
-->
<complexType>
<sequence>
<!--
The below achieves trimming of spaces either side,
but only when parsing. Nothing is added when unparsing.
-->
<element name="value" nillable="true"
dfdl:nilValue="-"
dfdl:lengthKind="delimited"
dfdl:textStringJustification="center"
dfdl:textTrimKind="padChar"
dfdl:textPadKind="none">
<simpleType>
<restriction base="xs:string">
<enumeration value="AB"/>
<enumeration value="ABC"/>
</restriction>
</simpleType>
</element>
</sequence>
</complexType>
</element>
The TDML file I created for this has these tests in it showing that this
works:
<parserTestCase name="foo1" root="Foo" model="s" roundTrip="onePass">
<document>- /</document>
<infoset>
<dfdlInfoset>
<ex:Foo xmlns=""><value xsi:nil="true"/></ex:Foo>
</dfdlInfoset>
</infoset>
</parserTestCase>
<parserTestCase name="foo2" root="Foo" model="s" roundTrip="twoPass">
<document> - /</document>
<infoset>
<dfdlInfoset>
<ex:Foo xmlns=""><value xsi:nil="true"/></ex:Foo>
</dfdlInfoset>
</infoset>
</parserTestCase>
<parserTestCase name="foo3" root="Foo" model="s" roundTrip="twoPass">
<document> AB /</document>
<infoset>
<dfdlInfoset>
<ex:Foo xmlns=""><value>AB</value></ex:Foo>
</dfdlInfoset>
</infoset>
</parserTestCase>
<parserTestCase name="foo4" root="Foo" model="s" roundTrip="onePass">
<document>AB /</document>
<infoset>
<dfdlInfoset>
<ex:Foo xmlns=""><value>AB</value></ex:Foo>
</dfdlInfoset>
</infoset>
</parserTestCase>
On Mon, Aug 8, 2022 at 10:22 AM Roger L Costello <coste...@mitre.org> wrote:
> Hi Mike,
>
>
>
> I gave your suggested approach a try. It failed.
>
>
>
> With this input:
>
>
>
> …/AB /…
>
>
>
> it works.
>
>
>
> With this input:
>
>
>
> …/ - /…
>
>
>
> it fails, producing this error:
>
>
>
> [error] Validation Error: Foo failed facet checks due to: facet
> enumeration(s): AB|ABC
>
>
>
> Further, even if the approach were to work with this example where the
> field length is 3, it would be an untenable approach for longer fixed
> fields. For example, if the field length was 10, then the nilValue would
> need something like 10-factorial whitespace-separated values.
>
>
>
> Do you have another suggested approach?
>
>
>
> /Roger
>
>
>
> *From:* Mike Beckerle <mbecke...@apache.org>
> *Sent:* Monday, August 8, 2022 9:38 AM
> *To:* users@daffodil.apache.org
> *Subject:* [EXT] Re: Conflicting requirements: fixed length field,
> nillable, some enumeration values shorter than the required length
>
>
>
> I would try making the nilValue "%SP;-%SP; -". That is two separate
> possibilities for nilValue, one is space-hyphen-space, the other just
> hyphen. (It's a whitespace-separated list of nil values tokens.)
>
>
>
> The first one will be used for unparsing. Both will be tried for parsing.
>
>
>
> That along with justification left might work.
>
>
>
>
>
>
>
>
>
>
>
>
>
> On Mon, Aug 8, 2022 at 8:01 AM Roger L Costello <coste...@mitre.org>
> wrote:
>
> Hi Folks,
>
> I have an input field that is fixed length (3). If there is no data, the
> field is to be populated with a hyphen (of course, it must be padded with
> spaces to the required length). The schema has a simpleType with
> enumeration facets. Some enumeration values are less than the required
> length.
>
> Here's how I specify the field:
>
> <xs:element name="Foo"
> nillable="true"
> dfdl:nilKind="literalValue"
> dfdl:nilValue="-"
> dfdl:lengthKind="explicit"
> dfdl:length="3"
> dfdl:textTrimKind="padChar"
> dfdl:textPadKind="padChar"
> dfdl:textStringPadCharacter="%SP;"
> dfdl:textStringJustification="center">
> <xs:simpleType>
> <xs:restriction base="xs:string">
> <xs:enumeration value="AB"/>
> <xs:enumeration value="ABC"/>
> </xs:restriction>
> </xs:simpleType>
> </xs:element>
>
> Notice dfdl:textStringJustification="center" which is fine for the
> nillable value (hyphen) but not for a regular value such as AB which should
> be left justified. As the schema is, the input could contain this (assume
> slash separators):
>
> .../ AB/...
>
> which is incorrect.
>
> So, there are conflicting requirements: the nillable value needs
> dfdl:textStringJustification="center" whereas the normal values need
> dfdl:textStringJustification="left". What to do about this?
>
> /Roger
>
>
