Hmmm. So an IVC element within an unordered sequence? When would it get
evaluated?
I think we should prevent this. The whole notion of unordered has to do with
positions of things in the representation. A non-represented element has no
business being in there.
So I think the same restriction should apply as for choice branches - no IVC
allowed.
________________________________
From: Taylor Wise
Sent: Friday, November 17, 2017 1:13:12 PM
To: Mike Beckerle; Steve Lawrence; dev@daffodil.apache.org
Subject: Unordered Sequence and Choice Branch Violations
While executing some existing tests I've come across a case that I need
guidance on.
Given the following test case:
<tdml:defineSchema name="simple_invalid_path_to_branch">
<dfdl:format ref="ex:daffodilTest1" lengthUnits="characters"
lengthKind="delimited" />
<xs:element name="USG_01">
<xs:complexType>
<xs:sequence dfdl:sequenceKind="unordered"
dfdl:separator=",">
<xs:element name="e1" type="xs:int" dfdl:lengthKind="delimited"
dfdl:initiator="a">
</xs:element>
<xs:element name="e2" type="xs:int" dfdl:lengthKind="delimited"
dfdl:initiator="b">
</xs:element>
<xs:element name="e3" type="xs:int" dfdl:lengthKind="delimited"
dfdl:initiator="c">
</xs:element>
<xs:element name="e4" type="xs:string" dfdl:lengthKind="delimited"
dfdl:inputValueCalc="{ ../ex:e3 }">
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<tdml:parserTestCase name="test_simple_invalid_path_to_branch"
model="simple_invalid_path_to_branch" description="Section 14 Sequence group
with left over data - DFDL-14-001R"
root="USG_01" roundTrip="false">
<tdml:document><![CDATA[b2,a1,a4,c3,ruh-oh!]]></tdml:document>
<tdml:errors>
<tdml:error>Schema Definition Error</tdml:error>
<tdml:error>Expression</tdml:error>
<tdml:error>../e3</tdml:error>
<tdml:error>navigates to another branch</tdml:error>
<tdml:error>e3</tdml:error>
</tdml:errors>
</tdml:parserTestCase>
The result of the test is the following:
edu.illinois.ncsa.daffodil.tdml.TDMLException: Did not find diagnostic message
"Expression" in any of the actual diagnostic messages:
Schema Definition Error: Branch of choice
ex:USG_01::LocalComplexTypeDef::sequence::choiceElement::LocalComplexTypeDef::choice::e4
cannot have the dfdl:inputValueCalc property.
Schema context: choice Location line 184 in
file:/tmp/simple_invalid_path_to_branch4208585747499063196.dfdl.xsd
Now, in the test you'll notice that there's no choice listed in the schema. But
because it's an unordered sequence, it gets transformed into a sequence of
choice.
Something like:
<xs:sequence dfdl:sequenceKind="ordered" dfdl:separator=",">
<xs:element name="choiceElement" minOccurs="0" maxOccurs="unbounded"
dfdl:occursCountKind="parsed">
<xs:complexType>
<xs:choice dfdl:choiceLengthKind="implicit">
<xs:element name="e1" type="xs:string" dfdl:initiator="a" />
<xs:element name="e2" type="xs:int" dfdl:initiator="b" />
<xs:element name="e3" type="xs:string" dfdl:initiator="c" />
<xs:element name="e4" type="xs:string" dfdl:inputValueCalc="{ ../ex:e3 }" />
</xs:choice>
</xs:complexType>
</xs:element>
</xs:sequence>
So does this now mean that this schema has to obey all the rules of choice?
That's not immediately obvious.
The spec states that IVC is "not allowed to appear on a local element or
element reference that is the root of a choice branch". e4 is now the root of a
choice branch.
Offending code:
final def branchesAreNotIVCElements = LV('branchesAreNotIVCElements) {
val branchesOk = groupMembersNoRefs map { branch =>
if (!branch.isRepresented) {
schemaDefinitionErrorButContinue("Branch of choice %s cannot have the
dfdl:inputValueCalc property.".format(branch.path))
false
} else true
}
assuming(branchesOk.forall { x => x })
}.value
About IVC from the spec:
It is a schema definition error if this property is specified on an element
which has an XSDL fixed or default property.
It is a schema definition error if dfdl:inputValueCalc and dfdl:outputValueCalc
are specified on the same element.
It is not possible to place this property in scope on a dfdl:format annotation.
This property is not allowed to appear on a local element or element reference
that is the root of a choice branch.
If this property appears on an element declaration or element reference schema
component, the appearance of any other DFDL properties on that component is a
schema definition error.
If this property appears on an element reference, then DFDL properties
expressed on the referenced global element declaration or its type are ignored.
If this property appears on an element declaration, then DFDL properties
expressed on its type are ignored.
