ISSUE-33: How can rr:template be used in an ObjectMapClass to produce IRI's or Strings
rr:template type in ObjectMapClass
How can rr:template be used in an ObjectMapClass to produce IRI's or Strings
- State:
- CLOSED
- Product:
- R2RML
- Raised by:
- David McNeil
- Opened on:
- 2011-03-10
- Description:
- From section A.2.2.2 of the R2RML spec http://www.w3.org/2001/sw/rdb2rdf/r2rml/#sec-emptable-mapping-table
rr:predicateObjectMap
[
rr:predicateMap [ rr:predicate emp:jobtype ];
rr:objectMap [ rr:template "http://example.com/emp/job/{job}" ]
];
This leads to the question: in an ObjectMapClass what is to be the datatype of the value produced by an rr:template expression? Choices I can think of are:
1) IRI - this leads to the question of how to use a template to produce a string? One would expect to use rr:termtype for this, but section 3.6.1.3 makes it clear that rr:termtype & rr:datatype are "relevant in an ObjectMap only if rr:column property is present as well". Another possibility is to require the user to create a SQLQuery that implements the desired template behavior in a projected column. Then the rr:termtype & rr:datatype properties can be used. But this seems like it is requiring the user to jump through unnecessary hoops.
2) String - then how to use a template to produce an IRI?
My recommendation is to clarify in the spec, in the context of an ObjectMapClass whether rr:template produces an IRI or a string and to allow rr:termtype and rr:datatype to be used in conjunction with rr:template. - Related Actions Items:
- No related actions
- Related emails:
- ISSUE-33 (rr:template type in ObjectMapClass): How can rr:template be used in an ObjectMapClass to produce IRI's or Strings [R2RML] (from sysbot+tracker@w3.org on 2011-03-10)
Related notes:
There was agreement that this needs to be changed. The termtype and datatype properties are intended to be used with the template property as well. Richard suggested a general refactoring of the spec to remove some of the parallelism. For the immediate needs to publish the spec, Souri will update sections 3.1.6.3 and 3.1.6.4.
David McNeil, 22 Mar 2011, 16:37:47R2RML Spec has been modified to take care of this.
Ashok Malhotra March 22, 2011
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