Reference Resolve

Torch needs to resolve references in the extracted data to ensure that all resources are correctly extracted and linked. This is done in the Reference Resolve step of the Torch pipeline.

Resolving References

Torch manages for each Attribute Group the Resources that have been assigned to it. This assignment is called a ResourceGroup (e.g. AttributeGroup_Observation,Observation1).

To resolve references, Torch uses the following steps for each Patient or the Core Resources:

1. Get all valid ResourceGroups: Torch retrieves all ResourceGroups that are valid for the current extraction.
2. Extract References: For each ResourceGroup, Torch extracts the references from the resources.
3. Load References: Torch checks if it already loaded the referenced resources in its cache.
   • If the resource is not loaded, Torch bundles all references and loads them in a single FHIR search request.
4. Assign References: Torch assigns the loaded resources to the ResourceGroup.
   • Performs a must-have check on the loaded resources.
   • For Patient resources, it also checks if the resources are allowed by the patient's consent.
   • If any must-have condition is violated, the referencing resource group is marked for deletion.
5. Update ResourceGroup: The ResourceGroup is updated with the loaded resources and their references.
6. Repeat for all ResourceGroups: Torch repeats the process for all newly added ResourceGroups until all references are resolved.