thiyanarumugam/health.fhir.cds

CDS Base Module

Sample Usage

This section focuses on samples depicting how to use this package to implement CDS related integrations

Prerequisites

1. Install Ballerina 2201.8.2 or later

1. Validate the context data of CDS request

Sample below is using the CDS request resource in health.fhir.r4.cds package.

import ballerina/log;
import ballerinax/health.fhir.cds;

public function main() returns error? {
    json cdsRequestPayload = {
        "hookInstance": "d1577c69-dfbe-44ad-ba6d-3e05e953b2ea",
        "fhirServer": "http://hapi.fhir.org/baseR4",
        "hook": "patient-view",
        "fhirAuthorization": {
            "access_token": "some-opaque-fhir-access-token",
            "token_type": "Bearer",
            "expires_in": 300,
            "scope": "user/Patient.read user/Observation.read",
            "subject": "cds-service4"
        },
        "context": {
            "userId": "Practitioner/example",
            "patientId": "593380",
            "encounterId": "89284"
        },
        "prefetch": {
            "patientToGreet": {
                "resourceType": "Patient",
                "gender": "male",
                "birthDate": "1925-12-23",
                "id": "1288992",
                "active": true
            }
        }
    };

    json cdsServiceJson = {
        "description": "An example of a CDS Service that returns a static set of cards",
        "hook": "patient-view",
        "id": "static-patient-greeter",
        "title": "Static CDS Service Example",
        "prefetch": {
            "patientToGreet": "Patient/{{context.patientId}}"
        }
    };

    cds:CdsService cdsService = check cdsServiceJson.cloneWithType();
    cds:CdsRequest cdsRequest = check cdsRequestPayload.cloneWithType();
    cds:CdsError? validationResult = cds:validateContext(cdsRequest, cdsService);
    if validationResult is cds:CdsError {
        log:printError(string `Error message: ${validationResult.message()}`);
        log:printError(string `Error description: ${validationResult.detail().description ?: ""}`);
        log:printError(string `Status code: ${validationResult.detail().code}`);
    } else {
        log:printInfo("Context validation is successful!");
    }
}

2. Prefetch validation

import ballerina/log;
import ballerinax/health.fhir.cds;

public function main() returns error? {
    json payload = {
        "hookInstance": "d1577c69-dfbe-44ad-ba6d-3e05e953b2ea",
        "fhirServer": "http://hapi.fhir.org/baseR4",
        "hook": "patient-view",
        "fhirAuthorization": {
            "access_token": "some-opaque-fhir-access-token",
            "token_type": "Bearer",
            "expires_in": 300,
            "scope": "user/Patient.read user/Observation.read",
            "subject": "cds-service4"
        },
        "context": {
            "userId": "Practitioner/example",
            "patientId": "593380",
            "encounterId": "89284"
        },
        "prefetch": {
            "patientToGreet": {
                "resourceType": "Patient",
                "gender": "male",
                "birthDate": "1925-12-23",
                "id": "1288992",
                "active": true
            }
        }
    };

    json cdsServiceJson = {
        "description": "An example of a CDS Service that returns a static set of cards",
        "hook": "patient-view",
        "id": "static-patient-greeter",
        "title": "Static CDS Service Example",
        "prefetch": {
            "patientToGreet": "Patient/{{context.patientId}}"
        }
    };

    cds:CdsService cdsService = check cdsServiceJson.cloneWithType();
    cds:CdsRequest cdsRequest = check payload.cloneWithType();
    cds:CdsRequest|cds:CdsError result = cds:validateAndProcessPrefetch(cdsRequest, cdsService);

    if (result is cds:CdsError) {
        log:printError(string `Error message: ${result.message()}`);
        log:printError(string `Error description: ${result.detail().description ?: ""}`);
        log:printError(string `Status code: ${result.detail().code}`);
    } else {
        log:printInfo(string `Validated CDS request: ${result.toJsonString()}`);
    }
}