Populating drop-down options in FHIR Core from Resources in DB

[allan-on]

Feature request

Syncing location (hierarchy) data from the server and populating drop-down options in a Questionnaire

Context

In Questionnaires where the user needs to input location-related data such as the name of a physical location or Health Facility tied to a jurisdiction, a selection from a list would offer the best UX.

Implementation

Server-side implementation

The implementation should provide syncing of location data from the server added through location hierarchy or practitioner assignments on FHIR Web.

• We can use the implementation that will be available on the FHIR Gateway that allows getting Location and LocationHierarchy details as part of the Practitioner details
• This will be once moving of the Practitioner details endpoint to plugins in the FHIR Gateway in [ServerSide] Move the Practitioner Details endpoint to plugins on the FHIR Gateway #2213 is done

Android FHIR SDK SDC Support

• Currently, it is only possible to use answerExpressions with an expression that takes a query and populates a drop-down item control. Support was added here Support for answerExpression extension google/android-fhir#1039

• This means that we can query against a Resource and use the values in a drop-down. This happens on loading of the Questionnaire and doesn't support multi-level selections. For instance, in a Questionnaire with multiple (multi-level) location selection options, a prior location selection within the same Questionnaire would not result in a change in the options in the next drop-down

• With initialExpression x-fhir-query support that will be introduced in Initial expression with x-fhir-query support google/android-fhir#2036 it'll be possible to Query for and set an initially selected option

FHIR Core implementation

• On FHIR Core we'd need to sync & persist the Location data using the location/practitioner details API.
  • We'll also need a menu option to trigger syncing of locations/hierarchy manually whenever assignment updates are done on FHIR Web
  • There might be performance implications depending on the amount of data that is being synced.
    • Might be beneficial to be able to define which locations to sync in the hierarchy defined

a) Drop-down selection

• The drop-down options can be populated using answerExpression. A sample implementation can be seen here Use initial expressions to select the initial value from a dropdown list populated using answer expressions google/android-fhir#1830 (comment)

b) Multi-level selections

• To implement multi-level selections that facilitate This would need SDK support for answerExpressions to work with an already loaded Questionnaire

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Additional Context

See Loading of data on SDC widgets meeting notes