That fixed it - thank you Steve!
One more question, if I may.
Here is the output that I am now getting:
<Characteristics>
<Characteristic-16>0</Characteristic-16>
<Characteristic-15>0</Characteristic-15>
<Characteristic-14>0</Characteristic-14>
<Characteristic-13>0</Characteristic-13>
<Characteristic-12>0</Characteristic-12>
<Characteristic-11>If the image is on removable media, copy it to and run
it from the swap file</Characteristic-11>
<Characteristic-10>Debugging information was removed and stored separately
in another file</Characteristic-10>
<Characteristic-9>The computer supports 32-bit words</Characteristic-9>
<Characteristic-8>0</Characteristic-8>
<Characteristic-7>0</Characteristic-7>
<Characteristic-6>0</Characteristic-6>
<Characteristic-5>0</Characteristic-5>
<Characteristic-4>0</Characteristic-4>
<Characteristic-3>0</Characteristic-3>
<Characteristic-2>0</Characteristic-2>
<Characteristic-1>Relocation information was stripped from
file</Characteristic-1>
</Characteristics>
That is okay, but I would like to get rid of the -N (e.g., Characteristic-1).
I'd like to output this XML:
<Characteristics>
<Characteristic->0</Characteristic->
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>If the image is on removable media, copy it to and run it
from the swap file</Characteristic>
<Characteristic>Debugging information was removed and stored separately in
another file</Characteristic>
<Characteristic>The computer supports 32-bit words</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>0</Characteristic>
<Characteristic>Relocation information was stripped from
file</Characteristic>
</Characteristics>
Even better, I'd like to omit completely Characteristic elements with no
message:
<Characteristics>
<Characteristic>If the image is on removable media, copy it to and run it
from the swap file</Characteristic>
<Characteristic>Debugging information was removed and stored separately in
another file</Characteristic>
<Characteristic>The computer supports 32-bit words</Characteristic>
<Characteristic>Relocation information was stripped from
file</Characteristic>
</Characteristics>
Is that possible (and still be able to unparse the XML)?
/Roger
-----Original Message-----
From: Steve Lawrence <[email protected]>
Sent: Monday, November 12, 2018 3:05 PM
To: [email protected]; Costello, Roger L. <[email protected]>
Subject: Re: Bug with hidden group containing an element with a 1-bit value?
I believe I have found the problem. In the dfdl:format tag, you have the
alignment and alignmentUnits set to 1-byte. Your unsignedint1 type explicitly
sets the alignmentUnits property to bits, which makes perfect sense. In side
each hidden group you have a sequence with an element that uses this type, e.g.:
<xs:group name="hidden_characteristic_bit1_Group">
<xs:sequence>
<xs:element name="Hidden_characteristic_bit1" type="unsignedint1" />
</xs:sequence>
</xs:group>
In addition to elements and simple types, alignment also applies to sequences
and choices. So in this case, the xs:sequence will have an alignmentUnit of
bytes, which ultimately causes multilpe bits to be skipped to deal with the
alignment of that sequence. The solution here is to either 1) set the
alignmentsUnits of that sequence to bits or 2) just set the alignmentUnits to
bits in the dfdl:format tag. If you do not ever expect to need to skip bits due
to alignment, then #2 probably makes the most sense to avoid these kinds of
subtle mistakes, and then explicitly set alignmentUnits to bytes in cases where
there explicit alignment is needed, if at all.
- Steve
On 11/12/18 1:37 PM, Costello, Roger L. wrote:
> Hello DFDL community,
>
> I am creating a DFDL schema for .exe files (Portable Executable file format).
>
> At one point in the file are 2-bytes that represent sixteen 1-bit flags.
>
> For each bit, if the bit = 1, then I want to output a message; otherwise
> output 0 (for now).
>
> To test that I am correctly reading the 2 bytes I did this:
>
> <xs:element name="Characteristics" type="xs:hexBinary" dfdl:length="2"
> dfdl:lengthKind="explicit" dfdl:lengthUnits="bytes" />
>
> The output contained the correct hex bytes:
>
> 07 01
>
> To test that I am correctly consuming each individual bit I did this:
>
> <xs:element name="Characteristic" type="unsignedint1" minOccurs="16"
> maxOccurs="16" />
>
> Here is the output:
>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>1</Characteristic>
> <Characteristic>1</Characteristic>
> <Characteristic>1</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>0</Characteristic>
> <Characteristic>1</Characteristic>
>
> You can see that those bits correspond to hex 07 01.
>
> I want the value of each <Characteristic> element to be a message, not 0/1.
> So, I used the dfdl:hiddenGroupRef approach to translate 0/1 to a message.
>
> <xs:element name="Characteristics">
> <xs:complexType>
> <xs:sequence>
> <xs:sequence
> dfdl:hiddenGroupRef="hidden_characteristic_bit16_Group" />
> <xs:element name="Characteristic-16" type="xs:string"
> dfdl:inputValueCalc="{
> if
> (fn:lower-case(xs:string(../Hidden_characteristic_bit16)) eq "1") then "The
> bytes of the word are reversed(obsolete)"
> else xs:string(../Hidden_characteristic_bit16)}" />
> <xs:sequence
> dfdl:hiddenGroupRef="hidden_characteristic_bit15_Group" />
> <xs:element name="Characteristic-15" type="xs:string"
> dfdl:inputValueCalc="{
> if
> (fn:lower-case(xs:string(../Hidden_characteristic_bit15)) eq "1") then "The
> image should only be run on a single processor computer"
> else xs:string(../Hidden_characteristic_bit15)}" />
> ...
> </xs:sequence>
> </xs:complexType>
> </xs:element>
>
> <xs:group name="hidden_characteristic_bit16_Group">
> <xs:sequence>
> <xs:element name="Hidden_characteristic_bit16" type="unsignedint1"
> dfdl:outputValueCalc="{ . }" />
> </xs:sequence>
> </xs:group>
> ...
> <xs:group name="hidden_characteristic_bit1_Group">
> <xs:sequence>
> <xs:element name="Hidden_characteristic_bit1" type="unsignedint1"
> dfdl:outputValueCalc="{ . }" />
> </xs:sequence>
> </xs:group>
>
> That produced this incorrect output:
>
> <Characteristic-16>0</Characteristic-16>
> <Characteristic-15>0</Characteristic-15>
> <Characteristic-14>0</Characteristic-14>
> <Characteristic-13>0</Characteristic-13>
> <Characteristic-12>0</Characteristic-12>
> <Characteristic-11>0</Characteristic-11>
> <Characteristic-10>0</Characteristic-10>
> <Characteristic-9>0</Characteristic-9>
> <Characteristic-8>0</Characteristic-8>
> <Characteristic-7>0</Characteristic-7>
> <Characteristic-6>0</Characteristic-6>
> <Characteristic-5>Aggressively trim the working
> set(obsolete)</Characteristic-5>
> <Characteristic-4>0</Characteristic-4>
> <Characteristic-3>0</Characteristic-3>
> <Characteristic-2>0</Characteristic-2>
> <Characteristic-1>0</Characteristic-1>
>
> Is there a bug with hidden groups containing an element with a 1-bit value?
>
> Note: here is how unsigned1 is defined:
>
> <xs:simpleType name="unsignedint1" dfdl:length="1" dfdl:lengthKind="explicit"
> dfdl:alignmentUnits="bits">
> <xs:restriction base="xs:unsignedInt"/> </xs:simpleType>
>
> /Roger
>
