Logical Model + Custom Resource

If you’re working with a custom format that you want to transform, you need create a model of your data to describe it to the FHIR Mapper. If you’re working with FHIR resources as your source data, Vonk already has the models available, so you can skip this step.

  1. Describe your logical model in Forge: see Logical Models. An example model is available and we’ll use it in this documentation.
../../_images/sample-logical-model.png
  1. Next, convert the logical model you’ve made to a custom resource:

    2.1. Ensure the .url starts with http://hl7.org/fhir/StructureDefinition (this is a temporary limitation).

    2.1.1. In our example, change from http://example.org/mappingengine/fhir/StructureDefinition/FakeInpatientDrugChart to http://hl7.org/fhir/StructureDefinition/FakeInpatientDrugChart.

    2.2. Set .kind to resource.

    2.3. Remove the URL from .type and set it to just a name.

    2.3.1. In our example, change from http://example.org/fhir/StructureDefinition/FakeInpatientDrugChart to FakeInpatientDrugChart.

    2.4. Add a .id element at the root level with the name of the custom resource.

    2.4.1. In our example, set .id to FakeInpatientDrugChart.

    2.5. Set the .baseDefinition to http://hl7.org/fhir/StructureDefinition/DomainResource.

    2.6. Delete the type field from the first .differential.element (and .snapshot.element if you have it):

    ../../_images/delete-first-type-from-logical.png

    2.7. If you only have a .snapshot in your model and no .differential, rename the .snapshot to .differential (this is a temporary limitation - basically, ensure that you have a .differential).

If you’d like to double-check, this is how our example custom resource looks like now with all the changes applied.

  1. Finally, upload your custom resource to Vonk’s /administration endpoint:

    3.1. PUT the resource to http(s)://<vonk-endpoint>/administration/StructureDefinition/<custom resource name>.

    3.1.1 In our example, PUT http://localhost:4080/administration/StructureDefinition/FakeInpatientDrugChart with the resource in the body.

With the custom resource uploaded to Vonk’s administration point, we have now taught Vonk about a new resource type!

You can verify this by running GET http(s)://localhost:4080/<custom resource name> (in our example GET http://localhost:4080/FakeInpatientDrugChart). The query will return 0 search results instead of an error message “Request for not-supported ResourceType(s)”.

Next we’ll create a mapping between our custom resource and FHIR STU3 resources.