Support slice-specific constraints

[jduteau]

I have a number of profiles where we do slicing and then we have constraints that are specific to one of the slices. It appears that the IBM validation applies all the constraints to all of the slices. If the constraint is expressed assuming the slice discriminator holds true, then this results in validation occurring when it shouldn't.

As an example, we sliced Organization.identifier based on the identifier system. We then had slice-specific validation based on the slices.

In slice A, we said that the identifier.value needed to be 9 digits
In slice B, we said that the identifier.value needed to be 5 or 7 digits.

When we ran examples against the validation, both constraints fired in both slices which raised errors.

The workaround was to include the slice discriminator in the constraint.

This resulted in the constraint changing from 'value.length() = 9' to 'system = 'X' implies value.length() = 9'. We could have also moved the constraint to identifier but we left it at the slice level for documentation purposes, i.e. it reads better if the constraint is specific to the slice.

Acceptance Criteria

1. GIVEN a constraint attached to one slice and not the others WHEN a resource is submitted for validation that includes elements in multiple slices THEN the constraint is only validated against the slice it is attached to AND not the other slices.

NOTE: I have included a sample StructureDefinition that shows the constraint attached to the specific slice.
StructureDefinition-IdentifiedOrganization.txt

[jduteau]

Here is an example of an IdentifiedOrganization.
Organization-SampleIdentifiedEstablishment.txt

[prb112]

We've upgraded to the latest, and I confirm the build is in 4.9.0, and we support slice specific constraints.