fhir 0.0.5

FHIR library of versions R4, STU3, DSTU2, and R5 (draft) for Dart & Flutter.

FHIR

A Dart/Flutter package for working with FHIR resources.

It contains packages for the 3 released FHIR versions:

• R4 v4.0.1
• Stu3 v3.0.2
• Dstu2 v1.0.2

As well as the R5 Preview #1:

• v4.2.0: R5 Draft

Say Hello!

• As all parts of this are new (FHIR, Flutter, using the two together), I'd love to hear from you if you're working in this space. You can email me at [e-mail].

How To Use

In order to use this package in your app, you must include the following in your pubspec.yaml file under dependencies:

dependencies:
  fhir: ^0.0.5

Or if you want to include the most recent unreleased version from Github

fhir:
  git:
    url: git://github.com/Dokotela/fhir.git

Then, in any file where you're going to be using it, simply import it like this:

import 'package:fhir/r4.dart';

Or, you may need to rename the package, for instance, there are some variables FHIR uses that overlap with dart:core, or if you're going to be using more than oen version of FHIR in the same file:

import 'package:fhir/r4.dart' as r4;
import 'package:fhir/stu3.dart' as stu3;

And then just remember to append r4 or stu3 to any variables you use from the library.

Currently this package is really just for serializing/deserializing FHIR data, and being able to create FHIR resources.

To do something like create a patient, you can do the following::

var newPatient = Patient(
  resourceType: 'Patient',
  name: [
    HumanName(family: 'LastName', given: ['FirstName'])
  ],
  birthDate: Date('2020-01-01'),
  gender: PatientGender.female,
);

If you're instead trying to get data from a server (currently I haven't implemented SMART on FHIR so it would need to be an open server, HAPI for instance - make sure you choose the right version you're interested in), a very simple example of querying and then printing the result:

import 'dart:convert';

import 'package:fhir/r4.dart';
import 'package:http/http.dart';

Future main() async {
  var server = 'http://hapi.fhir.org/baseR4';
  var headers = {'Content-type': 'application/json'};
  var desiredResource = 'Patient';
  var response = await get('$server/$desiredResource', headers: headers);
  var searchSetBundle = Bundle.fromJson(json.decode(response.body));
  print(searchSetBundle.toJson());
}

All of the FHIR resources are immutable classes using the freezed package, which means you can take advantage of it's functionality for things like copying/updating:

  var changePatientName = newPatient.copyWith(name: [
    HumanName(family: 'NewLastName', given: ['SameFirstName'])
  ]);

And that's essentially all there is at this point. This is still very much a developing package, so there are likely to be breaking changes as I try and figure out how it should all work. I welcome any and all feedback, suggestions or pull requests.

Upcoming

There are two big items I would really like to get to work to add functionality:

1. Database - I'm working on a locally embedded, encrypted database using Sembast and SQFlite. Feel free to take a look, it's in the basic branch of my vigor repository.
2. SMART - this one I could really use some help with. I think I understand the pieces, but I'm not sure the best way to try and implement it. But I do realize it's necessary to truly making this a useful package.

Validation

R5

• These are non-resource files that my package doesn't know how to read. From the sample files here: https://hl7.org/fhir/2020Feb/downloads.html, it won't properly serialize/deserialize package-min-ver.json, uml.json, hl7.fhir, hl7.fhir.r5.core.manifest.json, hl7.fhir.r5.expansions.manifest.json
• It finds that the Id field is too long for questionnaireresponse-extensions-QuestionnaireResponse-item-subject.json
• The padding in binary-example.json field renders it invalid

R4

• All of the downloads here: https://www.hl7.org/fhir/examples-json.zip have been run through a tester to ensure proper serialization/deserialization using this FHIR package
• I've compared each field from the input to the output and output to input as Maps. This should have revealed if any fields were created or deleted. It also avoids issues with fields in a different order from input to output.
• Known problems:

1. There is an ID field in questionnaireresponse-extensions-QuestionnaireResponse-item-subject.json in the examples seems to be too long
2. There is a Base64Binary binary-example.json field that has padding which renders it invalid
3. There's also this file, package-min-ver.json, that I have no idea what to do with.

Stu3

• All of the downloadable STU3 HL7 Examples, https://hl7.org/fhir/STU3/examples-json.zip have been run through the tester. Amazingly, it seemed to correctly run through all of them.

Dstu2

• All of the DSTU2 HL7 Examples from https://hl7.org/fhir/dstu2/validation-min.json.zip
• In https://www.hl7.org/fhir/DSTU2/searchparameter.html there is an issue with the SearchParameter: at least according to this website, it does appear that the field "base" and "description" should be required. However, many, many of the examples that are provided on the website do not have those fields, so I have not made them mandatory.
• In https://www.hl7.org/fhir/DSTU2/elementdefinition.html#ElementDefinition, it seems that in the type field, "code" is required, but if "_code" is present, this does not seem to be the case in the examples. I have therefore removed the requirement from the code field.
• There are private fields in this FHIR version that appear to correlate to the private Element fields in R4. I cannot find these specifically stated anywhere, so I'm going to assume all R4 private fields are valid as long as there is a corresponding public field. A few of these should actually be lists. But if they are not in the examples, then I do not know which. So there are likely some that should be lists that I have not implemented as such.
• Known Problems, a number of files appear to have Ids that are too long, all observations: observation-genetics-cg-prf-1a-Observation-gene-amino-acid-change.json, observation-genetics-cg-prf-1a-Observation-chromosome-genomicstart.json, observation-genetics-cg-prf-1a-Observation-condition-gene-dnavariant.canonical.json, observation-genetics-cg-prf-1a-Observation-condition-gene-dnavariant.json, observation-genetics-cg-prf-1a-Observation-gene-amino-acid-change.canonical.json, observation-genetics-cg-prf-1a-Observation-chromosome-genomicstart.canonical.json.

First Package

This is the first time I've ever created a package, feedback and pull requests are welcome. I've also been started to implement type checking using Freezed. But if you run into any issues with this, either incorrect validation, or frustrating to work with returned failures, please let me know.

Code Generation

I think it's the new compiling. It's actually great though, json_serializable and freezed are used extensively throughout. Note that sometimes freezed will give a stack overflow error if you try to do all code generation for the entire package at the same time. Also note that for fields that can take any resource, they have to be manually assigned. Currently this is done by passing the json object to resourceList. The fromJson code has to be changed in the 'g.dart' file.

Formatting Notes

• Class names: upper camel case.
• Variables: lower camel case.
• File names: snake case.
• FHIR nested classes (including enums) listed under the primary class
• There are a number of FHIR fields that are reserved words in Dart. For these, I have added a '_' to the end of the field. (note that this does not change the json format, as when that happens the @JsonKey has been added to the field like so:

@JsonKey(name: 'extension') List<FhirExtension> extension_,

A couple special notes about DSTU2

• Because Dstu2 is not formatted as well as the newer versions, a number of the names end up being extremely long. What I have decided to do is the following:
  • If the field/class id in the schema is a single word("id": "integer" or "id": "ValueSet"), that word is used as the field or class name.
  • If the id is more than a single word AND it is a primitive type ("id": "ValueSet.expansion.contains.display" which is a string), the last word is used as the type, in this case the field would be: String display
  • If the id is 2 words and is NOT a primitive type ("id": "ValueSet.expansion"), the type is the two words combined with upper camel case, and the field is the last word: ValueSetExpansion expansion
  • if the id is more than 2 words and NOT a primitive type ("id": "TestScript.setup.action.operation.requestHeader"), the type is the first, next to last and last word combined with upper camel case, and the field is the last word: TestScriptOperationRequestHeader requestHeader
• Many of the element fields I have included because they are included as part of the test resources. I could not find a full list online, so there may still be some element fields that I have missed.

FHIR datatypes (these are R4 (which is what everyone should be using, but since EHR vendors are doing everything they can to not share data, I am also working on stu3 and dstu2 as well)

PrimitiveTypes	GeneralTypes	MetadataTypes	SpecialTypes	DraftTypes
base64binary	address	contactDetail	dosage	population
boolean	age	contributor	elementDefinition	productedShelfLife
canonical	annotation	dataRequirement	extension	prodCharacteristic
code	attachment	parameterDefinition	meta	marketingStatus
date	codeableConcept	relatedArtifact	narrative	substanceAmount
dateTime	coding	triggerDefinition	reference
decimal	contactPoint	usageContext
id	count	relatedArtifact
instant	distance	triggerDefinition
integer	duration	usageContext
markdown	humanName	expression
oid	identifier
positiveInt	money
string	moneyQuantity
time	period
unsignedInt	quantity
uri	range
url	ratio
	sampledData
	signature
	simpleQuantity
	timing

ResourceTypes	by Category
Base
Individuals	Entities1	Entities2	Workflow	Management
Group	Endpoing	BiologicallyDerivedProduct	Appointment	Encounter
Patient	HealthcareService	Device	AppointmentResponse	EpisodeOfCare
Person	Location	DeviceMetric	Schedule	Flag
Practitioner	Organization	Substance	Slot	Library
PractitionerRole	OrganizationAffiliation		VerificationResult	List
RelatedPerson
Clinical
Summary	Diagnostics	Medications	CareProvision	RequestAndResponse
AdverseEvent	BodyStructure	Immunization	CarePlan	Communication
AllergyIntolerance	DiagnosticReport	ImmunizationEvaluation	CareTeam	CommunicationRequest
ClinicalImpression	ImagingStudy	ImmunizationRecommendation	Goal	DeviceRequest
DetectedIssue	Media	Medication	NutritionOrder	DeviceUseStatement
FamilyMemberHistory	MolecularSequence	MedicationAdministration	RequestGroup	GuidanceResponse
Procedure	Observation	MedicationDispense	RiskAssessment	SupplyDelivery
	QuestionnaireResponse	MedicationKnowledge	VisionPrescription	SupplyRequest
	Specimen	MedicationRequest
		MedicationStatement
Financial
Support	Billing	Payment	General
Coverage	Claim	PaymentNotice	Account
CoverageEligibilityRequest	ClaimResponse	PaymentReconciliation	ChargeItem
CoverageEligibilityResponse	Invoice		ChargeItemDefinition
EnrollmentRequest			Contract
EnrollmentResponse			ExplanationOfBenefits
			InsurancePlan
Foundation
Conformance	Terminology	Security	Documents	Other
CapabilityStatement	CodeSystem	AuditEvent	CatalogEntry	Basic
CompartmentDefinition	ConceptMap	Consent	Composition	Binary
ExampleScenario	NamingSystem	Provenance	DocumentManifest	Bundle
GraphDefinition	TerminologyCapabilities	DocumentReference		Linkage
ImplementationGuide	ValueSet			MessageHeader
MessageDefinition				OperationOutcome
OperationDefinition				Parameters
SearchParameter				Subscription
StructureDefinition
StructureMap
Specialized
Public Health And Research	Definitional Artifacts	Evidence Based Medicine	Quality Reporting And Testing	Medication Definition
ResearchStudy	ActivityDefinition	EffectEvidenceSynthesis	Measure	MedicinalProduct
ResearchSubject	DeviceDefinition	Evidence	MeasureReport	MedicinalProductAuthorization
	EventDefinition	EvidenceVariable	TestScript	MedicinalProductContraindication
	ObservationDefinition	ResearchDefinition	TestReport	MedicinalProductIndication
	PlanDefinition	ResearchElementDefinition		MedicinalProductIngredient
	Quesionnaire	RiskEvidenceSynthesis		MedicinalProductInteraction
	SpecimenDefinition			MedicinalProductManufactured
				MedicinalProductPackaged
				MedicinalProductPharmaceutical
				MedicinalProductUndesirableEffect
				SubstanceNucleicAcid
				SubstancePolymer
				SubstanceProtein
				SubstanceReferenceInformation
				SubstanceSpecification
				SubstanceSourceMaterial