Create dart data classes easily, fast and without writing boilerplate or running code generation.
This project is an enhanced fork of Dart Data Class Generator with additional bug fixes and features.
New Features
- Auto Enum Detection - Enums are detected automatically; no
// enum comment needed.
- Case-Insensitive Enum Matching -
fromMap matches enum names regardless of casing.
fromMap.use_as_cast Default On - as casting is enabled by default for cleaner null-safe code.- Nullable Enum Support - Nullable enums use
firstWhereOrNull and auto-import package:collection/collection.dart when needed.
Improvements
- Cleaner fromMap - Removed the extra
convertedMap indirection; direct map access everywhere.
- Enum Serialization - Uses the non-nullable enum type for lookups and only applies
?.name when the enum is nullable.
Previous Version Highlights
0.10.0
- Customizable quick fixes (
quick_fixes.show)
- Smart quick fixes hide already existing methods
- Equatable stringify support (
toString.useStringify)
fromMap.default_values controls defaults for nullable & required properties
0.9.0
- Fixed collection equality operators for non-Flutter projects
- Fixed null checks for collections in
fromMap()
- Fixed LinkedMap type errors
- Improved DateTime serialization (ISO 8601 format)
- Fixed enum serialization (string names instead of indices)
- Fixed copyWith for sealed class subclasses
- Automatic const constructors
- Separated serialization methods in quick fixes
Features
The generator can generate the constructor, copyWith, toMap, fromMap, toJson, fromJson, toString, operator == and hashCode methods for a class based on class properties or raw JSON.
Additionally the generator has a couple of useful quick fixes to speed up your development process. See the Additional Features Section for more.
If this extension is helpful to you, consider giving it a star on GitHub or leave a review on the Visual Studio Marketplace :heart:
Create Data Classes Based on Class Properties
Usage
You can generate data classes either by the quick fix dialog or by running a command. In the quick fix dialog you have the option to not only generate whole data classes but also only specific methods. The command has the advantage of being able to generate multiple classes at the same time.
Quick fix
- Create a class with properties.
- Place your cursor on the first line of the class, the constructor or a field.
- Hit CTRL + . (or CMD + . on Mac) to open the quick fix dialog.
- Choose one of the available options:
- Generate data class
- Generate constructor
- Generate copyWith
- Generate toMap
- Generate fromMap
- Generate toJson
- Generate fromJson
- Generate toString
- Generate equality
- Generate Equatable
Command
- Create a class with properties.
- Hit CTRL + P (or CMD + P on Mac) to open the command dialog.
- Search for Dart Data Class Tools Plus: Generate from class properties and hit enter.
- When there are multiple classes in the current file, choose the ones you'd like to create data classes of in the dialog.
It is also possible to run the generator on an existing data class (e.g. when some parameters changed). The generator will then try to find the changes and replace the class with its updated version. Note that custom changes to generated functions may be overridden.
You can also customize the generator for example to use Equatable for value equality. See the Settings section for more options.
Automatic const Constructors
If all properties in a class are final, the constructor will automatically be marked as const:
class User {
final String name;
final int age;
// Generated constructor will be:
const User({
required this.name,
required this.age,
});
}
Enums
- Enums are detected automatically (no
// enum comment required).
fromMap matches enum names case-insensitively.- Nullable enums use
firstWhereOrNull (auto-imports package:collection/collection.dart when needed).
- Enums serialize as string names (e.g.,
status.name) instead of indices for better readability and robustness.
Usage with Equatable
Although using the generator is fast, it still doesn't spare you from all the boiler plate necessary, which can be visually distracting. To reduce the amount of boiler plate needed, the generator works with Equatable. Just extend the class with Equatable or mix with EquatableMixin and the generator will use Equatable for value equality.
You can also use the setting dart-data-class-generator.useEquatable, if you always want to use Equatable for value equality.
Sealed Classes
The generator now supports generating copyWith methods for subclasses of sealed classes:
sealed class BaseEvent {}
class UserCreatedEvent extends BaseEvent {
final String userId;
final String email;
// copyWith will be generated correctly
}
Create Data Classes Based on JSON (Beta)
Usage
- Create an empty dart file.
- Paste the raw JSON without modifying it into the otherwise empty file.
- Hit CTRL + P (or CMD + P on Mac) to open the command dialog.
- Search for Dart Data Class Tools Plus: Generate from JSON and hit enter.
- Type in a class name in the input dialog. This will be the name of the top level class if the JSON contains nested objects, all other class names will be inferred from the JSON keys.
- When there are nested objects in the JSON, a dialog will appear if you want to separate the classes into multiple files or if all classes should be in the same file.
Note:
This feature is still in beta!
Many API's return numbers like 0 or 1 as an integer and not as a double even when they otherwise are. Thus the generator may confuse a value that is usually a double as an int.
Additional Features
The extension includes some additional quick fixes that might be useful to you:
Import refactoring
Sort imports alphabetically and bring them into the correct format easily.
Settings
You can customize the generator to only generate the functions you want in your settings file.
dart-data-class-generator.json.key_format: Whether to use snake_case or camelCase for the json keys. Options: variable, camelCase, snake_case.dart-data-class-generator.quick_fixes: If true, enables quick fixes to quickly generate data classes or specific methods only.dart-data-class-generator.quick_fixes.show: Array of quick fix names to show. Select which quick fixes should be available in the quick fix menu. Options: dataClass, constructor, copyWith, toMap, fromMap, toJson, fromJson, toString, stringify, equality, useEquatable. If empty, all enabled quick fixes will be shown. Quick fixes for methods that already exist in the class will not be shown.dart-data-class-generator.useEquatable: If true, uses Equatable for value equality and hashCode.dart-data-class-generator.fromMap.default_values: If true, checks if a field is null when deserializing and provides a non-null default value. This applies to both nullable and required (non-nullable) properties.dart-data-class-generator.fromMap.use_as_cast: If true (default: true), uses as casting in fromMap (e.g., map['name'] as String or map['name'] as String?).dart-data-class-generator.constructor.default_values: If true, generates default values for the constructor.dart-data-class-generator.constructor.required: If true, generates @required annotation for every constructor parameter. Note: The generator wont generate default values for the constructor if enabled!dart-data-class-generator.json.separate: Whether to separate a JSON into multiple files, when the JSON contains nested objects. Options: ask (choose manually every time), separate (always separate into multiple files), current_file (always insert all classes into the current file).dart-data-class-generator.override.manual: If true, asks, when overriding a class (running the command on an existing class), for every single function/constructor that needs to be changed whether the generator should override the function or not. This allows you to preserve custom changes you made to the function/constructor that would be otherwise overwritten by the generator.dart-data-class-generator.constructor.enabled: If true, generates a constructor for a data class.dart-data-class-generator.copyWith.enabled: If true, generates a copyWith function for a data class.dart-data-class-generator.copyWith.usesValueGetter: If true, uses ValueGetter for nullable types when generates copyWith.dart-data-class-generator.toMap.enabled: If true, generates a toMap function for a data class.dart-data-class-generator.fromMap.enabled: If true, generates a fromMap function for a data class.dart-data-class-generator.toJson.enabled: If true, generates a toJson function for a data class.dart-data-class-generator.fromJson.enabled: If true, generates a fromJson function for a data class.dart-data-class-generator.toString.enabled: If true, generates a toString function for a data class.dart-data-class-generator.toString.useStringify: If true and Equatable is used, generates stringify getter property instead of toString() method. If Equatable is not used, toString() will be generated instead.dart-data-class-generator.equality.enabled: If true, generates an override of the == (equals) operator for a data class.dart-data-class-generator.hashCode.enabled: If true, generates a hashCode function for a data class.dart-data-class-generator.hashCode.use_jenkins: If true, uses the Jenkins SMI hash function instead of bitwise operator from dart:ui.
Technical Improvements
Collection Equality
- Flutter projects: Uses
listEquals, mapEquals, setEquals from package:flutter/foundation.dart
- Non-Flutter projects: Uses
ListEquality().equals, MapEquality().equals, SetEquality().equals from package:collection/collection.dart
DateTime Serialization
- Serializes to ISO 8601 format:
toUtc().toIso8601String()
- Deserializes from ISO 8601:
DateTime.parse().toLocal()
Enum Serialization
- Serializes as string names:
enumValue.name
- Deserializes from string names using
firstWhere
Null Safety
- Proper null checks for nullable collections in
fromMap()
- Default empty collections for non-nullable collections
- Fixed file path handling for Windows, macOS, and Linux
- Proper handling of
LinkedMap from JSON decoding
Contributing
Contributions are welcome! Please feel free to submit a Pull Request.
License
See LICENSE.md for details.
