Yep, sounds right to me.
On 6/7/19 11:59 AM, Costello, Roger L. wrote:
> Hi Steve,
>
> Is this the rule: To indicate a _string_ value in an XPath expression, wrap
> the value within quotes (either single quotes or double quotes). If the value
> is not within an XPath expression, then do not wrap the value within quotes.
>
> Is that correct?
>
> /Roger
>
> -----Original Message-----
> From: Steve Lawrence <[email protected]>
> Sent: Friday, June 7, 2019 11:49 AM
> To: [email protected]
> Subject: [EXT] Re: A choiceBranchKey that specifies multiple value?
>
> The choiceDirectDispatchKey is a DFDL expression. In order to return a string
> value from an expression, you need to wrap it in quotes, otherwise it looks
> like a path. For example, in this expression:
>
> { rounded }
>
> There are no quotes, so it looks like a path, and so will return the value of
> the infoset element with name "rounded". On the otherhand, when there are
> quotes like this expression:
>
> { 'rounded' }
>
> That will returns the literal string "rounded", but without the quotes.
> So when we compare the value against choice branch key, were compare against
> the string value without quotes.
>
>
> On 6/7/19 11:35 AM, Costello, Roger L. wrote:
>> Steve wrote:
>>
>> 2) Have a more complex dispatch expression, something like:
>>
>> dfdl:choiceDispatchKey="{
>>
>> if (./num eq 1) then 'rounded'
>>
>> else if (./num eq 2) then 'square'
>>
>> else 'none' }"
>>
>> And change your choiceBranchKeys to "rounded", "square", and "none".
>>
>> Wow!
>>
>> I really like that solution.
>>
>> I implemented it and it works great. But it raises a question. Here is
>> the DFDL
>> schema:
>>
>> <xs:elementname="input">
>> <xs:complexType>
>> <xs:sequencedfdl:separator="%NL;"dfdl:separatorPosition="infix">
>> <xs:elementname="num"type="xs:integer"/>
>> <xs:choicedfdl:choiceDispatchKey="{ if (./num eq 1) then 'rounded'
>> else if (./num eq 2) then 'square' else 'none' }">
>> <xs:elementname="A"type="xs:string"
>> dfdl:initiator="("dfdl:terminator=")"
>> dfdl:choiceBranchKey="rounded"/>
>> <xs:elementname="B"type="xs:string"
>> dfdl:initiator="["dfdl:terminator="]"
>> dfdl:choiceBranchKey="square"/>
>> <xs:elementname="C"type="xs:string"
>> dfdl:initiator="%WSP*;"dfdl:terminator="%NL;"
>> dfdl:choiceBranchKey="none"/> </xs:choice>
>> </xs:sequence> </xs:complexType> </xs:element>
>>
>> Notice that there are quotes around round, square, and none in the
>> expression for dfdl:choiceDispatchKey but there are no quotes around
>> them in dfdl:choiceBranchKey. I initially did this:
>>
>> dfdl:choiceBranchKey=" 'rounded' "
>>
>> Notice the single quotes within the double quotes. That resulted in an error.
>>
>> Why don't I need those single quotes to indicate that we are matching
>> to a _/string/_?
>>
>> /Roger
>>
>> -----Original Message-----
>> From: Steve Lawrence <[email protected]>
>> Sent: Friday, June 7, 2019 10:47 AM
>> To: [email protected]
>> Subject: [EXT] Re: A choiceBranchKey that specifies multiple value?
>>
>> A few ways to handle this:
>>
>> 1) Daffodil has an extension to allow a space separated list of
>> choiceBranchKeys, so if you know all the keys for the third branch you can
>> do this:
>>
>> dfdl:choiceBranchKey="3 4 5 6"
>>
>> But if you need it to be portable to other DFDL implementations (e.g.
>>
>> IBM), or if you need something more generic (e.g. all nums greater
>> than
>>
>> 3 should have no parents) then you need to go a different route.
>>
>> 2) Have a more complex dispatch expression, something like:
>>
>> dfdl:choiceDispatchKey="{
>>
>> if (./num eq 1) then 'rounded'
>>
>> else if (./num eq 2) then 'square'
>>
>> else 'none' }"
>>
>> And change your choiceBranchKeys to "rounded", "square", and "none".
>>
>> This works well if there aren't too many different keys/branches, but
>> if there are, then the if else expression can get pretty complicated,
>> so we sometimes use the next alternative.
>>
>> 3) Nested choices act sort of like a default if the dispatch doesn't match
>> anything:
>>
>> <xs:choice>
>>
>> <xs:choice dfdl:choiceDispatchKey="{ ./num }">
>>
>> <xs:element name="A" dfdl:choiceBranchKey="1" ... />
>>
>> <xs:element name="B" dfdl:choiceBranchKey="2" ... />
>>
>> </xs:choice>
>>
>> <xs:element name="C" ... />
>>
>> </xs:choice>
>>
>> So we first try the first branch of the outer choice, which is a
>> choice dispatch. If the dispatch key doesn't match any of the branch
>> keys, then we try the second branch of the outer choice. Which in this
>> case is our element C with no parens.
>>
>> On 6/7/19 10:28 AM, Costello, Roger L. wrote:
>>
>> > Hello DFDL community,
>>
>> >
>>
>> > My input file has a number (num), followed by a comma-separated
>> pair
>>
>> > of values, enclosed within either round parentheses, square
>> parentheses, or no parentheses.
>>
>> >
>>
>> > * If num=1 then the initiator and terminator are rounded parentheses.
>>
>> > * If num=2 then the initiator and terminator are square parentheses.
>>
>> > * If num=3, 4, 5, ... then there is no parentheses.
>>
>> >
>>
>> > The below DFDL schema works for num=1, num=2, and num=3. But it is
>>
>> > silent on other values of num (4, 5, ...). Is there a way to have a
>>
>> > choiceBranchKey for multiple values, e.g.,
>>
>> >
>>
>> > dfdl:choiceBranchKey="3...infinity"
>>
>> >
>>
>> > <xs:element name="input">
>>
>> > <xs:complexType>
>>
>> > <xs:sequence dfdl:separator="%NL;"
>> dfdl:separatorPosition="infix">
>>
>> > <xs:element name="num" type="xs:integer" />
>>
>> > <xs:choice dfdl:choiceDispatchKey="{ ./num }">
>>
>> > <xs:element name="A" type="xs:string"
>>
>> > dfdl:initiator="(" dfdl:terminator=")"
>>
>> > dfdl:choiceBranchKey="1" />
>>
>> > <xs:element name="B" type="xs:string"
>>
>> > dfdl:initiator="[" dfdl:terminator="]"
>>
>> > dfdl:choiceBranchKey="2" />
>>
>> > <xs:element name="C" type="xs:string"
>>
>> > dfdl:initiator="%WSP*;"
>> dfdl:terminator="%NL;"
>>
>> > dfdl:choiceBranchKey="3" />
>>
>> > </xs:choice>
>>
>> > </xs:sequence>
>>
>> > </xs:complexType>
>>
>> > </xs:element>
>>
>> >
>>
>
