Also, explicit choice lengths aren't implemented yet. The dfdl:choiceLengthKind and dfdl:choiceLength properties are currently ignored. There is a pull request to add the support, but it's needs some changes before it can be merged.
- Steve On 6/3/19 2:40 PM, Beckerle, Mike wrote: > The most common use cases come from COBOL REDEFINES where a typical union of > record types is made the fixed length of the longest one. Everything in such > data is typically fixed length. These are also almost always going to have > dfdl:choiceDispatchKey - because it is typical that there is a field to > distinguish the various record formats. > > > C language unions have the same behavior, but those aren't often used to > define > record structures in files, whereas in COBOL they almost always ARE used to > define record structures in files. > > > > -------------------------------------------------------------------------------- > *From:* Costello, Roger L. <coste...@mitre.org> > *Sent:* Monday, June 3, 2019 1:54:43 PM > *To:* users@daffodil.apache.org > *Subject:* Got a good use case for dfdl:choiceLengthKind? > > Hello DFDL community, > > I am trying to understand choiceLengthKind. Do you have a compelling use case > for it? > > I tried the following for dfdl:choiceLengthKind="explicit" > > The input contains a person’s name. If the name is less than 10 characters, > then > it’s just the firstname. Otherwise, it’s the firstname and last name. > > <xs:elementname="input"> > <xs:complexType> > <xs:choicedfdl:choiceLengthKind="explicit"> > <xs:elementname="firstname"type="xs:string"dfdl:choiceLength="10"/> > <xs:elementname="firstname-lastname"type="xs:string"dfdl:choiceLength="20"/> > </xs:choice> > </xs:complexType> > </xs:element> > > For reasons I do not understand, the first choice (the firstname element) is > always selected. > > This input: > > John > > Produces this XML: > > <input> > <firstname>John</firstname> > </input> > > And this input: > > John Alexander Smith > > Produces this XML: > > <input> > <firstname>John Alexander Smith</firstname> > </input> > > Why is that? > > /Roger >
