SMART Client for NodeJS

High-level API

In this mode you create a framework-specific API that is easier to use. Currently, we have adapters for Express and HAPI. Pull requests are welcome for other frameworks. Here is how to use that:

const smart = require("../lib/express")(options);
// or
const smart = require("../lib/hapi")(options);

Then just use the smart.authorize or other methods as described in their manuals:

• Express
• HAPI

Low-level API

In this mode you start by creating one configuration (options) object and one storage object (that implements The storage interface) and pass those as parameters for the functions as shown below.

authorize(request, response, options, storage)

This function should be called when you have a request to an URL with launch and iss parameters or alternatively a fhirServiceUrl parameter. When you launch your app from outside (from an EHR or a test launcher like https://launch.smarthealthit.org), your launchUri endpoint will be called with launch and iss parameters. Than you can use this function to initiate the launch sequence. An express example might look like this:

const smart = require("../lib");
// ...
app.get("/launch", (req, res) => smart.authorize(req, res, options, storage));

completeAuth(request, storage)

The login function above will redirect the browser to the authorization endpoint of the SMART server. Depending on the requested scopes, the user might be asked to select a patient or practitioner, authorize the app and so on. Eventually, the user will be redirected back to your site at your options.redirectUri. At that point you should have received a code that needs to be exchanged for an access token. To do so, you can use the completeAuth function like so (express example):

const smart = require("../lib");
// ...
app.get("/redirect", (req, res) => {
    smart.completeAuth(req, storage)
        .then(client => client.request("/Patient"))
        .then(result => res.json(result.data))
        .catch(error => res.status(500).send(error.stack));
})

Configuration Options

The following options are supported:

• clientId - string, required - The Client ID that you were given after registering your app with the authorization server.
• redirectUri - string, required - The location to redirect to, once the user have authorized the launch.
• serverUrl - string, optional - The base URL of the Fhir server. If you specify this in your options you will be able to call your launchUri endpoint without any parameters and it will initiate a standalone launch sequence against this server. You can also pass a fhirServiceUrl query parameter to your launchUri endpoint which will take precedence over the config option value. Finally, if your launch endpoint is called with iss and launch parameters (which will happen when launched from EHR), iss will become the used server and the fhirServiceUrl url parameter (if any) and the serverUrl option (if any) will be ignored.
• scope - string, optional - Space-separated list of scopes as described in http://docs.smarthealthit.org/authorization/scopes-and-launch-context/. Strictly speaking, this is option is not required but you will typically want access to certain resources and the scope should be used to request that access.
• clientSecret - string, optional If you registered your app as confidential client you should have been given a clientSecret that you have to set here.
• getStorage(request) - function, optional A function that will return a custom storage object. See The storage interface below for details.

Use these options while creating a SMART api:

const smart = require("../lib/express")({
    scope      : "openid profile offline_access",
    redirectUri: "/",
    clientId   : "my-client-id"
});
// ...

or you just pass them to functions if you prefer the low-level api:

const smart = require("../lib");
const options = {
    scope      : "openid profile offline_access",
    redirectUri: "/",
    clientId   : "my-client-id"
};
smart.authorize(req, res, options, storage)
// ...

Contribution and development

This library is written in typescript and the framework adapters are written in pure JavaScript. For best development experience you might want to have a few terminals running (cd into the project folder first):

• npm run build:watch - will watch TS files for changes and automatically re-build the JS versions in /lib.
• npm run test:watch - will run tests on any change so that if you introduce an issue you will know immediately.
• npm start - will run the node example on http://localhost:3000
  • npm run start:express - will run the express example on http://localhost:3000. You will have to do cd examples/express && npm i when you run this for the first time.
  • npm run start:hapi - will run the HAPI example on http://localhost:3000. You will have to do cd examples/hapi && npm i when you run this for the first time.
• npm run build or npm test if you want to build or test on demand instead of in watch mode.