fhir_generator
A generator for fhir dart classes with json artifacts. Thie generator uses the freezed package to generate the data classes. It also uses all the primitive_types from the fhir package.
How to Use
To use the generator you have to dart file containing a main function that runs the buildRunner and passes the arguments to it. An example looks like this.
void main(List args) {
buildRunner(args);
}
After that, run the following command dart [name-of-runner-file].dart [json-directory] [generation-directory]. The first argument is the directory containing all json files while the second argument contains the path to the build directory for all dart classes.
Type of files
To generated all the files you need to maintain the following directory structure inside your project where the runner file is located:
- abstract/
- extendables/
- backbone_element.dart
...
- primitive_types/
- base64binary.dart
...
- abstracts.dart
- pre_code/
- code_system_pre_code.txt
...
- json_directory/
- base_types/
- address.json
...
- code_systems/
- administrative_gender.json
...
- extensions/
- structureDefinition.json
...
- resources/
- patient.json
...
- value_sets/
- address_use.json
...
Abstracts
The abstracts directory contains all the primitive_types from the fhir package. Inside the extendablesfolder you can create your manual data classes for inheritance. The best example is extension.dart which is used to mark all child extensions as Type extension. The class looks like this.
class Extension extends Element {
final FhirUri url;
const Extension._(this.url);
factory Extension.fromJson(Map json) =>
Extension._(json['url']);
Map toJson() => {...super.toJson(), "uri": this.url};
}
pre_code
The pre_code directory contains all the template files for creating a specific resource and then run the freezed build runner over it. An example is resource_pre_code.txt. You can create your own templates or change the current ones. This is especially useful, if you create your own generator.
import 'package:freezed_annotation/freezed_annotation.dart';
import '{BUILD_PATH}/abstracts/abstracts.dart';
import '{BUILD_PATH}/code_systems/code_systems.dart';
import '{BUILD_PATH}/base_types/base_types.dart';
//THIS FILE IS AUTO GENERATED! DO NOT EDIT!
part '{FILE_NAME}.freezed.dart';
part '{FILE_NAME}.g.dart';
@freezed
class {RESOURCE_NAME} extends Resource with _${RESOURCE_NAME} {
factory {RESOURCE_NAME}({
{RESOURCE_CONSTRUCTOR}
}) = _{RESOURCE_NAME};
factory {RESOURCE_NAME}.fromJson(Map json) =>
_${RESOURCE_NAME}FromJson(json);
}
json-directory
The json-directory is the folder containing all the files to be build which contains
base_types
Alle the base_data_types similiar to the datatypes of fhir An example is address.json. All base_type files will be put into the generated-directory/base_types/ directory.
{
"name": "Address",
"element": {
"use": "AddressUseCode",
"type": "AddressTypeCode",
"text": "",
"line": [""],
"city": "",
"district": "",
"state": "",
"postalCode": "",
"country": "",
"period": "Period"
}
}
A generated version of this class looks like the following.
import 'package:freezed_annotation/freezed_annotation.dart';
import '../../abstracts/abstracts.dart';
import '../../code_systems/code_systems.dart';
import '../../base_types/base_types.dart';
//THIS FILE IS AUTO GENERATED! DO NOT EDIT!
part 'address.freezed.dart';
part 'address.g.dart';
@freezed
class Address extends Element with _$Address {
factory Address({
String? id,
List? extension,
AddressUseCode? use,
AddressTypeCode? type,
String? text,
List? line,
String? city,
String? district,
String? state,
String? postalCode,
String? country,
Period? period
}) = _Address;
factory Address.fromJson(Map json) =>
_$AddressFromJson(json);
}
These base types can also extend other class as Element or use generic types. An example is group_member.json.
{
"name": "OpenImisGroupMember",
"extends": "BackboneElement",
"element": {
"entity": "Reference"
}
}
The extends key allows to change from what class the child should inherit. The generated version would look like this.
import 'package:freezed_annotation/freezed_annotation.dart';
import '../../abstracts/abstracts.dart';
import '../../code_systems/code_systems.dart';
import '../../base_types/base_types.dart';
//THIS FILE IS AUTO GENERATED! DO NOT EDIT!
part 'open_imis_group_member.freezed.dart';
part 'open_imis_group_member.g.dart';
@freezed
class OpenImisGroupMember extends BackboneElement with _$OpenImisGroupMember {
factory OpenImisGroupMember({
List? modifierExtension,
String? id,
List? extension,
Reference? entity
}) = _OpenImisGroupMember;
factory OpenImisGroupMember.fromJson(Map json) =>
_$OpenImisGroupMemberFromJson(json);
}
To use generic types use the typing keyword and set it to true as done in coding.json. The you can use T as your generic type.
{
"name": "Coding",
"typing": true,
"element": {
"system": "",
"version": "",
"code": "T",
"display": "",
"userSelected": ""
}
}
code_systems
The code_systems directory contains all code systems from your fhir api. These code_systems can be downloaded from your fhir specific website and look like administrative_gender.json. Very important is the concept key.
"concept": [
{
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/codesystem-concept-comments",
"valueString": "Male"
}
],
"code": "male",
"display": "Male",
"definition": "Male."
},
{
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/codesystem-concept-comments",
"valueString": "Female"
}
],
"code": "female",
"display": "Female",
"definition": "Female."
},
...
]
All code systems will be put into generated-directory/code_systems/ and contain _code with the data as enum at the end of their file name. An example is administrative_gender_code.dart.
import 'package:freezed_annotation/freezed_annotation.dart';
//THIS FILE IS AUTO GENERATED! DO NOT EDIT!
enum AdministrativeGenderCode {
@JsonValue("male")
value_male,
@JsonValue("female")
value_female,
@JsonValue("other")
value_other,
@JsonValue("unknown")
value_unknown,
}
value_sets
Simaliar to code systems there are value sets, which you can download from your fhir specific api documentation. The value sets are used to make an actually fhir Coding class. An example is administrative_gender.json. Important is the compose key with the proper reference to the id of the actually Code (enum class).
"compose": {
"include": [
{
"system": "http://hl7.org/fhir/administrative-gender"
}
]
}
The generated file contains _coding at the end of the file name and is put into the same directory as the code systems. An example is administrative_gender_coding.dart.
import 'package:freezed_annotation/freezed_annotation.dart';
import '../../base_types/base_types.dart';
import '../../abstracts/abstracts.dart';
import 'administrative_gender_code.dart';
//THIS FILE IS AUTO GENERATED! DO NOT EDIT!
part 'administrative_gender_coding.freezed.dart';
part 'administrative_gender_coding.g.dart';
@freezed
class AdministrativeGenderCoding with _$AdministrativeGenderCoding {
factory AdministrativeGenderCoding({
@Default(FhirUri.asConst("http://hl7.org/fhir/administrative-gender", ConstUri("http://hl7.org/fhir/administrative-gender"),true)) FhirUri system,
required AdministrativeGenderCode code,
}) = _AdministrativeGenderCoding;
factory AdministrativeGenderCoding.fromJson(Map json) =>
_$AdministrativeGenderCodingFromJson(json);
}
extensions
Extensions are fhir specific resources that can be downloaded from your fhir specific api documentation website. These are structure definitions like resources. Important is the snapshot key. An example is StructureDefinition-patient-is-head.json.
"snapshot": {
"element": [
{
"id": "Extension",
"path": "Extension",
"short": "IsHead (Patient)",
"definition": "Whether the Patient/Insuree is the Head of the Family.",
"min": 0,
"max": "*",
"base": {
"path": "Extension",
"min": 0,
"max": "*"
},
...
]
}
]
},
These extensions will be put into the generated-folder/extensions/. An example is patient_is_head.dart.
import 'package:freezed_annotation/freezed_annotation.dart';
import '../../abstracts/abstracts.dart';
import '../../code_systems/code_systems.dart';
import '../../base_types/base_types.dart';
//THIS FILE IS AUTO GENERATED! DO NOT EDIT!
part 'patient_is_head.freezed.dart';
part 'patient_is_head.g.dart';
@freezed
class PatientIsHead extends Extension with _$PatientIsHead {
factory PatientIsHead({
String? id,
List? extension,
@Default(FhirUri.asConst("https://openimis.github.io/openimis_fhir_r4_ig/StructureDefinition/patient-is-head", ConstUri("https://openimis.github.io/openimis_fhir_r4_ig/StructureDefinition/patient-is-head"),true)) FhirUri url,
Boolean? valueBoolean
}) = _PatientIsHead;
factory PatientIsHead.fromJson(Map json) =>
_$PatientIsHeadFromJson(json);
}
resources
Resources are basically the same as extensions. The generated files will be put into generated-directory/resources/.
Example
An example containing the jsons and the build files is in the directory example_json/ and example_generated.
2 Nov 17, 2022
9 Apr 30, 2021
35 Jan 2, 2023
10 Dec 19, 2022
14 Nov 9, 2022
0 Jan 30, 2022
193 Jan 7, 2023
70 Sep 28, 2022
5 Jul 10, 2021
12 Nov 18, 2022