FHIR Client
Ruby FHIR client.
Supports:
- FHIR R4, STU3 and DSTU2
- JSON and XML
- All CRUD, including version read and history
- Transactions and Batches
- Search
- Operations (e.g.
$everything
,$validate
) - Support for OAuth2
Getting Started
$ bundle install
$ bundle exec rake fhir:console
Creating a Client
client = FHIR::Client.new(url)
This client supports two modes of operation: basic and advanced. The basic mode is useful for simple operations because it promotes an ActiveRecord-like style of interaction. The advanced mode is less developer-friendly, but is currently necessary if you would like to use the entire range of operations exposed by FHIR.
Basic Usage
Associate the client with the model:
FHIR::Model.client = client
The FHIR models can now be used to directly interact with a FHIR server.
# read an existing patient with an ID of 'example'
patient = FHIR::Patient.read('example')
# update a patient
patient.gender = 'female'
patient.update # saves the patient
# create a patient
patient = FHIR::Patient.create(name: {given: 'John', family: 'Doe'})
#create a patient with specific headers
patient = FHIR::Patient.new(name: {given: 'John', family: 'Doe'}).create({Prefer: "return=representation"})
# search patients
results = FHIR::Patient.search(given: 'John', family: 'Doe')
results.count # results in an enumeration
# delete the recently created patient
patient.destroy
Advanced Usage
Changing FHIR Versions
The client defaults to R4
but can be switched to DSTU2
or STU3
. It can also attempt to autodetect the FHIR version based on the metadata
endpoint.
# autodetect the FHIR version
client = FHIR::Client.new(url)
version = client.detect_version
if version == :stu3
puts 'FHIR Client using STU3'
elsif version == :dstu2
puts 'FHIR Client using DSTU2'
elsif version == :r4
puts 'FHIR Client using R4'
end
# tell the client to use R4
client.use_r4
# now use the client with the DSTU2 models
patient = FHIR::Patient.read('example')
patient = client.read(FHIR::Patient, 'example').resource
# tell the client to use STU3 (default)
client.use_stu3
# now use the client normally
patient = FHIR::STU3::Patient.read('example')
patient = client.read(FHIR::STU3::Patient, 'example').resource
# tell the client to use DSTU2
client.use_dstu2
# now use the client with the DSTU2 models
patient = FHIR::DSTU2::Patient.read('example')
patient = client.read(FHIR::DSTU2::Patient, 'example').resource
Changing FHIR Formats
The client defaults to json
representation of resources but can be switched to xml
representations.
client = FHIR::Client.new(url)
# Tell the client to use xml
client.default_xml
# Tell the client to use json
client.default_json
Configuration
You can specify additional properties for the client
:
client.additional_headers = {Prefer: 'return=representation'}
client.proxy = 'https://your-proxy.com/'
CRUD Examples
# read an existing patient with id "example"
patient = client.read(FHIR::Patient, "example").resource
# read specifying Formats
patient = client.read(FHIR::Patient, "example", FHIR::Formats::FeedFormat::FEED_JSON).resource
# create a patient
patient = FHIR::Patient.new
patient_id = client.create(patient).id
# update the patient
patient.gender = 'female'
client.update(patient, patient_id)
# conditional update
p_identifier = FHIR::Identifier.new
p_identifier.use = 'official'
p_identifier.system = 'http://projectcrucible.org'
p_identifier.value = '123'
patient.identifier = [ p_identifier ]
searchParams = { :identifier => 'http://projectcrucible.org|123' }
client.conditional_update(patient, patient_id, searchParams)
# conditional create
ifNoneExist = { :identifier => 'http://projectcrucible.org|123' }
client.conditional_create(patient, ifNoneExist)
# destroy the patient
client.destroy(FHIR::Patient, patient_id)
Searching
# via GET
reply = client.search(FHIR::Patient, search: {parameters: {name: 'P'}})
# via POST
reply = client.search(FHIR::Patient, search: {body: {name: 'P'}})
bundle = reply.resource
patient = bundle&.entry&.first&.resource
Fetching a Bundle
reply = client.read_feed(FHIR::Patient) # fetch Bundle of Patients
bundle = reply.resource
bundle.entry.each do |entry|
patient = entry.resource
puts patient.name[0].text
end
puts reply.code # HTTP 200 (or whatever was returned)
puts reply.body # Raw XML or JSON
Transactions
# Create a patient
@patient = FHIR::Patient.new
@patient.id = 'temporary_id'
# Create an observation
@observation = FHIR::Observation.new
@observation.status = 'final'
@coding = FHIR::Coding.new
@coding.system = 'http://loinc.org'
@coding.code='8302-2'
@observation.code = FHIR::CodeableConcept.new
@observation.code.coding = [ @coding ]
@quantity = FHIR::Quantity.new
@quantity.value = 170
@quantity.unit = 'cm'
@quantity.system = 'http://unitsofmeasure.org'
@observation.valueQuantity = @quantity
@reference = FHIR::Reference.new
@reference.reference = "Patient/#{@patient.id}"
@observation.subject = @reference
# Submit them both as a transaction
@client.begin_transaction
@client.add_transaction_request('POST',nil,@patient)
@client.add_transaction_request('POST',nil,@observation)
reply = @client.end_transaction
OAuth2 Support
client = FHIR::Client.new(url)
client_id = 'example'
client_secret = 'secret'
options = client.get_oauth2_metadata_from_conformance
if options.empty?
puts 'This server does not support the expected OAuth2 extensions.'
else
client.set_oauth2_auth(client_id, client_secret, options[:authorize_url] ,options[:token_url], options[:site])
reply = client.read_feed(FHIR::Patient)
puts reply.body
end
License
Copyright 2014-2022 The MITRE Corporation
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.