Thanks Mike. I implemented your approach. It fails to detect invalid input. Let
me explain.
Input specifications:
* Fixed length field (3)
* Nillable, hyphen is the nil value, the hyphen may be anywhere within the
3 character field
* Values must be left-justified
Here are examples of valid inputs:
…/AB /…
…/ABC/…
…/- /…
.../ - /…
…/ -/…
Your solution permits this input (I tested it, Daffodil gives no error or
warning):
…/ AB/…
Notice that the value is right-justified. That is invalid.
/Roger
/Roger
From: Mike Beckerle <mbecke...@apache.org>
Sent: Monday, August 8, 2022 3:58 PM
To: users@daffodil.apache.org
Subject: [EXT] Re: Conflicting requirements: fixed length field, nillable, some
enumeration values shorter than the required length
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<mailto: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<mailto:mbecke...@apache.org>>
Sent: Monday, August 8, 2022 9:38 AM
To: users@daffodil.apache.org<mailto: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<mailto: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
