If you want different element names, there's really way to avoid a
choice. You can get fancy with a hidden group, restriction, choice
dispatch and checkConstraints, and that avoids parsing the same field
twice, but it's very ugly and I wouldn't recommend it. I've put an
example of what this might look like at the end of this email.
In general, I would recommend not trying to have separate valid/invalid
elements, but instead parse the the field and rely on restrictions for
validation. For example:
<element name="field" dfdl:lengthKind="delimited" dfdl:terminator="%NL;">
<simpleType>
<restriction base="xs:string" />
<pattern value="[0-9][a-zA-Z]" />
</restriction>
</simpleType>
</element>
This works very similar, but now field is used for the well-formed
content, regardless if it's valid or not, and the restriction will be
used to validate it, either with Daffodils internal "limited"
validation, "full" Xerces validation, or external validation. An added
benefit it is doesn't have to parse the data twice for invalid data.
Below is the approach mentioned at the top. Note that it uses the same
technique as above, but it hides the field element and uses choice
dispatch, inputValueCalc, and outputValueCalc to create the
invalid/valid elements.
<group name="hiddenField">
<sequence>
<element name="field" dfdl:terminator="%NL;"
dfdl:outputValueCalc="{ if (fn:exists(../valid)) then ../valid
else ../invalid }">
<simpleType>
<restriction base="xs:string">
<pattern value="[0-9][a-zA-Z]" />
</restriction>
</simpleType>
</element>
</sequence>
</group>
<element name="root">
<complexType>
<sequence>
<sequence dfdl:hiddenGroupRef="ex:hiddenField" />
<choice dfdl:choiceDispatchKey="{
xs:string(dfdl:checkConstraints(./field)) }">
<sequence dfdl:choiceBranchKey="true">
<element name="valid" type="xs:string"
dfdl:inputValueCalc="{ ../field }" />
</sequence>
<sequence dfdl:choiceBranchKey="false">
<element name="invalid" type="xs:string"
dfdl:inputValueCalc="{ ../field }" />
</sequence>
</choice>
</sequence>
</complexType>
</element>
On 2023-09-07 05:04 PM, Roger L Costello wrote:
Hi Folks,
Good input contains a digit followed by a letter, e.g., this is good
input: 1H
Anything else is bad input, e.g., this is bad input: 1H23
If the input is good, I want to put the input into a <valid> element, e.g.,
<valid>1H</valid>
If the input is bad, I want to put the input into an <invalid> element,
e.g.,
<invalid>1H23</invalid>
This DFDL seems to work:
<xs:choice>
<xs:sequencedfdl:terminator="%NL;">
<xs:elementname="valid"type="xs:string"dfdl:lengthKind="pattern"
dfdl:lengthPattern="[0-9][a-zA-Z]"/>
</xs:sequence>
<xs:elementname="invalid"type="xs:string"/>
</xs:choice>
But that doesn’t seem like a good solution. Is there a better way to
solve this problem?
/Roger
