Model Generator

This model generator can be used to generate JsonSerializable models

Run

flutter packages run model_generator

Model file

By default, the model generator looks for the model yaml file in model_generator/config.yaml. If you want to overwrite this, specify it in your pubspec.yaml file by using config_path. Example of the pubspec.yaml file if you want to use a custom model file location:

model_generator:
  config_path: my_model_dir/config.yaml

You can also specify a command line parameter to override the location for a single run. For this, use the --path command line parameter. Example:

flutter packages run model_generator --path my_other_model_dir/config.yaml

Default setup

Example of the pubspec.yaml file if you want to use a custom base_directory for all your models Default is /lib/model you can override it for all your models like this:

model_generator:
  base_directory: custom_models

this will write all your models to /lib/custom_models path will be added after the base_directory

FVM support

If you are using fvm for managing your flutter version. You can add an option to the model generator as well to run with fvm. add an option use_fvm and set it to true. (by default it is set to false)

model_generator:
  use_fvm: true

== and hashCode

If you want the generated models to include code for == and hashCode, you can turn it on in pubspec.yaml. Defaults to false. All fields are taken into consideration for the generated code.

model_generator:
  equals_and_hash_code: true

or to override the values per object:

UserModel:
  path: webservice/user
  equals_and_hash_code: false
  properties:
    id:
      type: int

Ignored fields

If you wish to ignore certain fields when generating the == and hashCode methods, you can mark those fields with ignore_equality: true.

Note: Models with all fields ignored will report a zero hash code and equal only on identity

UserModel:
  path: webservice/user
  equals_and_hash_code: false
  properties:
    id:
      type: int
      ignore_equality: true
    include:
      type: string

explicit_to_json

By default json_serializable will not generate the toJson methods on an other json_serializable object or list or map. With the model_generator we can enable this by default since 5.0.0 You can override it at a global level:

model_generator:
  explicit_to_json: false

or to override the values per object:

UserModel:
  path: webservice/user
  explicit_to_json: false
  properties:
    id:
      type: int

toString

If you want the generated models to include generated toString code, you can turn it on in pubspec.yaml. Defaults to false. All fields are taken into consideration for the generated code.

model_generator:
  to_string: true

or to override the values per object:

UserModel:
  path: webservice/user
  to_string: false
  properties:
    id:
      type: int

Extra imports and annotations

If you wish for extra import statements in the generated files and/or extra annotations on the generated model classes, you can specify those in pubspec.yaml

model_generator:
  extra_imports:
    - 'package:flutter/foundation.dart'
  extra_annotations:
    - '@immutable'

or to override the values per object:

UserModel:
  path: webservice/user
  extra_imports:
  extra_annotations:
    - '@someAnnotation'
  properties:
    id:
      type: int

Default values

Since version 5.6.0 default values are supported for properties. You can specify a default value for both required and optional properties by adding default_value: ... to the property definition.

Note: Default values are taken exactly how they are specified in the yaml file, this means for example that you will need to quote strings correctly, ensure imports are there, ensure the value is a constant, ...

UserModel:
  path: webservice/user
  extra_imports:
  extra_annotations:
    - '@someAnnotation'
  properties:
    id:
      type: int
      default_value: 1
    name:
      type: string
      required: true
      default_value: "'an example quoted string'"

Generics support support

If you want your models to generate code that can be used in combination with generics. use this:

model_generator:
  generate_for_generics: true

or to override the default generate_for_generics value in the pubspec.yaml

UserModel:
  path: webservice/user
  generate_for_generics: true
  converters:
    - DateTimeConverter
  properties:
    id:
      type: int

Extends

If you want your models to expand any other model use extends:

Note: It is not supported to extend custom models

UserDetails:
  path: webservice/user
  extends: UserModel
  properties:
    name:
      type: string

Default setup

Example of the model_generator/config.yaml file

UserModel:
  path: webservice/user
  converters:
    - DateTimeConverter
  properties:
    id:
      type: int
    name:
      type: string
    salary:
      type: double
    something:
      type: dynamic
    isLoggedIn:
      type: bool
      default_value: false
    roles:
      type: array
      items:
        type: string
    birthday:
      type: date
    addresses:
      type: array
      items:
        type: Address
    idToAddress:
      type: map
      items:
        key: String
        value: Address
    securityRole:
      type: string
      jsonKey: securityIndicator
    dynamicField:
      type: dynamic
    includeIfNullField:
      include_if_null: false #If this field is null, this field will not be added to your json object (used for PATCH models)
      type: string
    ignoreField:
      ignore: false #this field will not be final, and not be used in the json parsing
      type: string
    mutableField:
      non_final: true #Field will not be marked final
      type: string
    changedAt:
      type: datetime
    idToAddressList:
      type: map
      items:
        key: String
        value: List<Address>

Address:
  path: webservice/user #Can also be package:... and/or end with the actual file (.dart)
  properties:
    street:
      type: string

#Custom base_directory
CustomBaseDirectoryObject:
  base_directory: custom_models
  path: webservice
  properties:
    path:
      type: string

#Custom json converter. Use with converters property on models
DateTimeConverter:
  type: json_converter
  path: converter/

Enum support

Add enums with custom values

Gender:
  path: webservice/user
  type: enum
  properties:
    MALE:
      value: _mAl3
    FEMALE:
      value: femAle
    X:
      value: X
    Y:

Generate mapping

For enums, it is also possible to have a map generated that maps from the enum value to its string representation and reverse. To enable this, use generate_map: true

Gender:
  path: webservice/user
  type: enum
  generate_map: true
  properties:
    MALE:
      value: _mAl3
    FEMALE:
      value: femAle
    X:
      value: X
    Y:

Generate mapping extensions

When generating maps, it is also possible to specify that special extension functions should be added that return either the string value or that takes a string value and tries to convert it to the enum value. To enable this, use generate_map: true AND generate_extensions: true

Gender:
  path: webservice/user
  type: enum
  generate_map: true
  generate_extensions: true
  properties:
    MALE:
      value: _mAl3
    FEMALE:
      value: femAle
    X:
      value: X
    Y:

Use unknownEnumValue

UnknownEnumTestObject:
  path: webservice
  properties:
    path:
      unknown_enum_value: X
      type: Gender

Automatic case conversion

By default all fields will be converted into uppercase. You can control this behavior globally for all enums or per-enum by setting the uppercase_enums property to true ( default) or false

model_generator:
  uppercase_enums: false

UnknownEnumTestObject:
  path: webservice
  uppercase_enums: false
  properties:
    path:

Custom object

Support for custom objects that are not generated by the model generator

CustomObject:
  path: data/custom/
  type: custom

Required methods inside your class

  factory {Model_Name}.fromJson(Map<String, dynamic> json) => _${Model_Name}FromJson(json);

  Map<String, dynamic> toJson() => _${Model_Name}ToJson(this);

fromJson & toJson

Support for custom objects but use fromJson & toJson instead of full object parsing:

CustomObjectFromToJson:
  path: data/custom/
  type: custom_from_to_json

Required functions outside your class

{Model_Name} handle{Model_Name}FromJson(object) => {Model_Name}.fromJson(object);

{Original_Type} handle{Model_Name}ToJson({Model_Name} data) => data.toJson();

fromJson & toJson override

Support for custom objects but use fromJson & toJson instead of full object parsing:

UserModel:
  path: webservice/user
  properties:
    description: The time at which the user has last updated his information
    changedAt:
      type: datetime
      fromJson: handleFromJsonWithCustomCode
      toJson: handleToJsonWithCustomCode

Required functions outside your file. (extra import should be used)

JsonConverter support

You can specify custom json converters to be used for types that match

UserModel:
  path: webservice/user
  converters:
    - DateTimeConverter
  properties:
    changedAt:
      type: datetime

Specify the custom JsonConverter object as a known type to resolve it

DateTimeConverter:
  type: json_converter
  path: converter/

Documentation support

You can specify description on models, enum, fields and on enum entries. This description will be used verbatim to generate a code comment for that class/enum/field

UserModel:
  path: webservice/user
  description: The model holding user data
  converters:
    - DateTimeConverter
  properties:
    description: The time at which the user has last updated his information
    changedAt:
      type: datetime

Static creator support

You can specify static_create on objects or globally in the pubspec.yaml file. If this is specified, a static creator method called create will be generated referencing the factory constructor. This static method can be used as a function reference. Defaults to false

UserModel:
  path: webservice/user
  static_create: true
  properties:
    changedAt:
      type: datetime

Retrofit compute support

Retrofit has added compute function support for decoding json payload in version 3.0.0. This requires top-level functions with a certain signature. You can have model generator generate these for you by setting retrofit_compute: true in the pubspec.yaml file:

model_generator:
  retrofit_compute: true

Model Generator

Run

Model file

Default setup

FVM support

== and hashCode

Ignored fields

explicit_to_json

toString

Extra imports and annotations

Default values

Generics support support

Extends

Default setup

Enum support

Generate mapping

Generate mapping extensions

Use unknownEnumValue

Automatic case conversion

Custom object

Required methods inside your class

fromJson & toJson

Required functions outside your class

fromJson & toJson override

Required functions outside your file. (extra import should be used)

JsonConverter support

Documentation support

Static creator support

Retrofit compute support

Libraries

model_generator package