FHIR‑Path Demo

This playground is a Flutter web build of a small app that runs the same FHIRPath implementation documented on this site: the model-independent fhir_path engine via its R4 binding, fhir_r4_path. Under the hood it creates a FHIRPathEngine, parses your expression, and evaluates it with evaluateWithContext against the resource you provide.

How to use it:

• Context Resource (left): paste any FHIR R4 resource as JSON. It is used as the evaluation context, %resource, and %rootResource. The pre-loaded example is a QuestionnaireResponse.
• FHIRPath Expression (right): type an expression and press Evaluate (or hit Enter). The pre-loaded expression walks the questionnaire answers with descendants().
• Results: shown as a JSON list — primitive results as values, complex results as JSON objects. Errors (bad JSON, invalid expressions) are shown in place of results.

Credit to fhirpath.js, whose demo inspired this one.

Here's the live FHIRPath playground link for full screen: