API

SUSHI exposes a fshToFhir function that can be used to convert FSH strings to FHIR JSON.

Syntax

fshToFhir(fshString[, options])

Parameters

fshString - A string containing FHIR Shorthand definitions.

options - An object which can have any combination of the following attributes:

• canonical - A string used to specify the canonical URL.
• version - A string used to specify the version.
• fhirVersion - A string used to specify the version of FHIR to use. Note that SUSHI only supports FHIR R4 and R5.
• dependencies - An array of objects used to specify dependencies required for processing the FSH. Each object should have a packageId and version, and optionally a uri.
• logLevel - A string that specifies what level of logging to use when processing FSH. Options are silent, debug, info, warn, and error.
• snapshot - (EXPERIMENTAL) A boolean that specifies whether to generate the snapshot data element in Structure Definition output (default: false)

See the configuration documentation for more information on canonical, version, fhirVersion, and dependencies. These properties correspond to the properties of the same name that are used in sushi-config.yaml.

Return Value

A Promise that resolves to an object with the following attributes:

• fhir - An array of FHIR definitions generated from the input FSH.
• errors - An array of objects containing any errors detected during processing. Each object has a message with the error message and optionally has input and location properties with additional information.
• warnings - An array of objects containing any warnings detected during processing. Each object has a message with the warning message and optionally has input and location properties with additional information.

Usage

To use fshToFhir, you must first install fsh-sushi as a dependency of your project:

 npm install fsh-sushi

Once fsh-sushi is installed as a dependency of your project, you can import and use this function as shown:

import { sushiClient } from 'fsh-sushi';

// Example basic usage
sushiClient
  .fshToFhir('Your FSH here')
  .then((results) => {
    // handle results
  })
  .catch((err) => {
    // handle thrown errors
  });

// Example usage with options
sushiClient
  .fshToFhir('Your FSH here', {
    canonical: "http://example.com",
    version: "1.2.3",
    fhirVersion: "4.0.1",
    dependencies: [{ packageId: "hl7.fhir.us.core", version: "3.1.0" }],
    logLevel: "error",
  })
  .then((results) => {
    // handle results
  })
  .catch((err) => {
    // handle thrown errors
  });