mixed node kind in cube data

[giacomociti]

Describe the bug

Affected functionalities (all that apply)

• CSV Mapping
• Transformation
• Publishing
• Other

Relevant links

query returning an example of inconsistent data (a dimension with
constraint sh:nodeKind sh:IRI but having both IRI and literal values).

To Reproduce
Steps to reproduce the behavior:

1. Create a new cube from CSV
2. Apply transformation
3. Edit metadata linking to a shared dimension some values of a dimension (but not all of them)
4. Publish

Expected behavior

The constraint for the dimension should have sh:nodeKind sh:IRIOrLiteral instead of sh:IRI.

Screenshots

Desktop (please complete the following information):

• OS: Windows 11
• Browser: chrome

Additional context

There is a proposal of disallowing mixed node kinds. If applied, cube creator should prevent publishing invalid data.

[tpluscode]

I the correct node kind set when you transform again after editing the metadata?

[giacomociti]

by "editing the metadata" you mean for example linking every value to some shared dimension term? Because the node kind is set by the pipeline (<#toCubeShape>) based on the actual observations (and does not cover sh:IRIOrLiteral unlike the new implementation in barnard59). So the only chance to avoid the issue is to ensure all the values for a dimension have the same node kind (either IRI or Literal)

[Rdataflow]

@giacomociti WRT the spec at https://cube.link/#null-empty-values
it would be the most obvious to reuse cube:Undefined in this case.

... so nodeKind would be consistently IRI 👍

[giacomociti]

agreed, we should be using cube:Undefined.

There is an external application which may be affected by the change, so we'll probably evolve both the cube and the app in the future.

[Rdataflow]

@giacomociti to increase the reusability of cube:Undefined it might be good to establish labels using schema:name and maybe some other useful properties.

first brainstorming:

cube:Undefined  schema:name  "Undefined" , "Undefined"@en , "Unbestimmt"@de , "Indéfini"@fr , "Indefinito"@it , "Indefini"@rm .

possibly other attributes i.e. WDYT?

cube:Undefined  schema:identifier  ""^^cube:Undefined ;
    schema:position  ""^^cube:Undefined .