I have a question for more experienced Daffodil maintainers. Suppose a schema
contains some fixed="constant" attributes:
<xs:complexType name="Limits">
<xs:sequence>
<xs:element name="sync0" fixed="210" type="idl:uint8"/>
<xs:element name="sync1" fixed="13" type="idl:uint8"/>
<xs:element name="id" fixed="34" type="idl:uint8"/>
<xs:element name="length" fixed="0" type="idl:uint8"/>
<xs:element name="checksum" type="idl:uint16"/>
</xs:sequence>
</xs:complexType>
<xs:element name="LimitsDecl" type="idl:Limits"/>
</xs:schema>
If a TDML test suite turns on validation="on", Daffodil runtime1 will call
Xerces to perform validation on an XML infoset and Xerces will report a
validation error if, say, element sync0 does not contain the right value:
[Fail] limits_parse
Failure Information:
(Implementation: daffodil) Validation errors found where none were expected
by the test case.
Validation Error: cvc-elt.5.2.2.2.2: The value '208' of element 'sync0'
does not match the {value constraint} value '210'.
I want Daffodil runtime2 to detect the presence of a fixed="constant" attribute
on a schema grammar object and generate C code to check that the corresponding
C struct member contains the right value. However, I don't know how to write
code to find the "fixed" attribute on a schema grammar object when runtime2
calls a class like BinaryIntegerKnownLengthCodeGenerator. I set a breakpoint
in the debugger but a quick search found the fixed attribute only in a shareKey
value.
How can I detect the presence of the fixed attribute and get its value in
BinaryIntegerKnownLengthCodeGenerator?
John
