fhir.js

JavaScript client for FHIR

Goals:

• Support FHIR CRUD operations
• Friendly and expressive query syntax
• Support for adapters that provide idiomatic interfaces in angular, jQuery, extjs, etc
• Support for access control (HTTP basic, OAuth2, Cookies)
• ...

Development

Node.js is required for build.

We recommend installing Node.js using nvm

Build & test:

git clone https://github.com/FHIR/fhir.js
cd fhir.js
npm install

# build fhir.js
npm run-script build

# run tests in node
npm run-script test

# run tests in phantomjs
npm run-script integrate

API

Create instance of the FHIR client

To communicate with concrete FHIR server, you can create instance of the FHIR client, passing a configuration object & adapter object. Adapters are implemented for concrete frameworks/libs (see below).

var config = {
  // FHIR server base url
  baseUrl: 'http://myfhirserver.com',
  auth: {
     bearer: 'token',
     // OR for basic auth
     user: 'user',
     pass: 'secret'
  },
  // Valid Options are 'same-origin', 'include'
  credentials: 'same-origin',
  headers: {
    'X-Custom-Header': 'Custom Value',
    'X-Another-Custom': 'Another Value',
  }
}

myClient = fhir(config, adapter)

Config Object

The config object is an object that is passed through the middleware chain. Any values in the config object that are not mutated by middleware will be available to the adapter.

Because middleware mutates the config, it is strongly recommended when implementing an adapter to not directly rely on config passed in.

baseUrl

This is the full url to your FHIR server. Resources will be appended to the end of it.

auth

This is an object representing your authentication requirements. Possible options include:

bearer

This is your Bearer token when provided, it will add an Authorization: Bearer <token> header to your requests.

user

This is your Basic auth Username.

When you provide both user name and password, basic auth will be used.

pass

This is your basic auth password.

When you provide both user name and password, basic auth will be used.

credentials

This option controls the behaviour of sending cookies to the remote server. Refer to the table below for how to configure the option for your desired adapter.

| Adapter | credentials | Result | |----------|---------------|---------------------------| | Native | 'same-origin' | Cookies are sent to the server, if it is on the same host as the origin sender | | Native | 'include' | Send cookies to all hosts | | jQuery | 'same-origin' | ignored | | jQuery | 'include' | Send cookies to all hosts | | yui | 'same-origin' | ignored | | yui | 'include' | Send cookies to all hosts | | angular | 'same-origin' | ignored | | angular | 'include' | ignored | | node | 'same-origin' | ignored | | node | 'include' | ignored |

headers

A key:value object that represents headers. This object is passed through to you configured adapter.

If you choose to add custom headers to your requests, you should ensure that the server that you are talking to supplies the appropriate headers. Further reading on Allowed Headers: https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS

const config = {
  headers: {
    'X-Custom-Header': 'Custom Value',
    'X-Another-Custom': 'Another Value',
  }
}

Adapter implementation

Currently each adapter must implement an http(requestObj) function:

Structure of requestObj:

• method - http method (GET|POST|PUT|DELETE)
• url - url for request
• headers - object with headers (i.e. {'Category': 'term; scheme="sch"; label="lbl"'}

and return promise (A+)

http(requestObj).then(success, error)

where: success - success callback, which should be called with (data, status, headersFn, config)

• data - parsed body of responce
• status - responce HTTP status
• headerFn - function to get header, i.e. headerFn('Content')
• config - initial requestObj passed to http

error - error callback, which should be called with (data, status, headerFn, config)

Here are implementations for:

• AngularJS adapter
• jQuery adapter
• Node adapter
• YUI adapter
• Native adapter

Conformance & Profiles

Resource's CRUD

Create Resource

To create a FHIR resource, call myClient.create(entry, callback, errback), passing an object that contains the following properties:

• resource (required) - resource in FHIR json
• tags (optional) - list of categories (see below)

In case of success,the callback function will be invoked with an object that contains the following attributes:

• id - url of created resource
• content - resource json
• category - list of tags

var entry = {
  category: [{term: 'TAG term', schema: 'TAG schema', label: 'TAG label'}, ...]
  resource: {
    resourceType: 'Patient',
    //...
  }
}

myClient.create(entry,
 function(entry){
    console.log(entry.id)
 },
 function(error){
   console.error(error)
 }
)

Get resource

To get one specific object from a resource (usually by id), call fhir.read({type: resourceType}). To specify the patient identifier, call fhir.read({type: resourceType, patient: patientIdentifier})

Examples:

fhir.read({type: 'Patient', patient: '8673ee4f-e2ab-4077-ba55-4980f408773e'})

Search Resource

To search a resource, call fhir.search({type: resourceType, query: queryObject}), where queryObject syntax fhir.js adopts mongodb-like query syntax (see):

{name: 'maud'}
//=> name=maud

{name: {$exact: 'maud'}}
//=> name:exact=maud

{name: {$or: ['maud','dave']}}
//=> name=maud,dave

{name: {$and: ['maud',{$exact: 'dave'}]}}
//=> name=maud&name:exact=Dave

{birthDate: {$gt: '1970', $lte: '1980'}}
//=> birthDate=gt1970&birthDate=lte1980

{subject: {$type: 'Patient', name: 'maud', birthDate: {$gt: '1970'}}}
//=> subject:Patient.name=maud&subject:Patient.birthDate=gt1970

{'subject.name': {$exact: 'maud'}}
//=> subject.name:exact=maud

Update Resource

To update a resource, call fhir.update({type: resourceType, id: identifier, resource: resourceObject}). In case of success,the callback function will be invoked.

Example:

 	this.fhirClient.update({
            type: "Patient",
            id: 1,
            resource: {
		name: 'New Name'
            }
        }).catch(function(e){
            console.log('An error happened while updating patient: \n' + JSON.stringify(e));
            throw e;
        }).then(function(bundle){
            console.log('Updating patient successed');
            return bundle;
        });

Delete Resource

To update a resource, call fhir.delete({type: resourceType, id: identifier}).

For more information see tests

AngularJS adapter: ng-fhir

AngularJS adapter after npm run-script build can be found at dist/ngFhir.js

Usage:

angular.module('app', ['ng-fhir'])
  .config(['$fhirProvider', function ($fhirProvider) {
    $fhirProvider.baseUrl = 'http://try-fhirplace.hospital-systems.com';
    $fhirProvider.auth = {
      user: 'user',
      pass: 'secret'
    };
    $fhirProvider.credentials = 'same-origin'
  }])
  .controller('mainCtrl', ['$scope', '$fhir', function ($scope, $fhir) {
    $fhir.search(
      {
        type: 'Patient',
        query: {name: 'emerald'}
      }).then(
      function (successData) {
        $scope.patients = successData.data.entry;

      },
      function (failData) {
        $scope.error = failData;
      }
    );
  }]);  

jQuery adapter: jqFhir

jQuery build can be found at dist/jqFhir.js

Example app

Usage:

<script src="./jquery-???.min.js"> </script>
<script src="./jqFhir.js"> </script>

// create fhir instance
var fhir = jqFhir({
    baseUrl: 'https://ci-api.fhir.me',
    auth: {user: 'client', pass: 'secret'}
})

fhir.search({type: 'Patient', query: {name: 'maud'}})
.then(function(bundle){
  console.log('Search patients', bundle)
})

Node.js adapter: npm install fhir.js

Via NPM you can npm install fhir.js. (If you want to work on the source code, you can compile coffee to js via npm install, and use ./lib/adapters/node as an entrypoint.)

var mkFhir = require('fhir.js');

var client = mkFhir({
    baseUrl: 'http://try-fhirplace.hospital-systems.com'
});

client
    .search( {type: 'Patient', query: { 'birthdate': '1974' }})
    .then(function(res){
        var bundle = res.data;
        var count = (bundle.entry && bundle.entry.length) || 0;
        console.log("# Patients born in 1974: ", count);
    })
    .catch(function(res){
        //Error responses
        if (res.status){
            console.log('Error', res.status);
        }

        //Errors
        if (res.message){
            console.log('Error', res.message);
        }
    });

YUI adapter: yuiFhir

YUI build can be found a