Search

FHIR search operations search through an existing set of resources by a set of search criteria supplied as parameters to the search. The Swift framework provides the FHIRSearch class to configure and execute searches.

Usage

Searches are configured in a NoSQL-like approach proposed and used by fhir.js.

Configuration

A search for all medication orders for patient with a known id can be as simple as:

let search = MedicationOrder.search(["patient": id])

Searching for all male patients in the Boston area with the exact family name "Willis" would be achieved with:

let search = Patient.search([
    "address": "Boston",
    "gender": "male",
    "family": ["$exact": "Willis"]
])

This will translate into a REST request against:

Patient?address=Boston&gender=male&family:exact=Willis

These two searches are generated with convenience methods provided by all FHIRResource subclasses. You can also create FHIRSearch instances manually:

let search = FHIRSearch(query: [
    "subject": [
        "$type": "Patient",
        "name": "Bruce",
        "birthDate": ["$lt": "1970"]
    ]
])

Execution

The perform(server:) method on the previously created FHIRSearch instances can be used to execute the search query to retrieve the result Bundle:

search.perform(smart.server) { bundle, error in
    if nil != error {
        // there was an error
    }
    else {
        let bruces = bundle?.entry?
            .filter() { return $0.resource is Patient }
            .map() { return $0.resource as! Patient }
            
            // now `bruces` holds all known Patient resources
            // named Bruce and born earlier than 1970
    }
}