json2dartgen 1.1.0

A CLI tool to generate Dart models from JSON, with json_serializable support and copyWith methods.

json2dartgen

A CLI tool to generate Dart model classes from JSON. Supports json_serializable, copyWith, and optional snake_case → camelCase conversion.

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Features

• Automatically generate Dart classes from any JSON file
• json_serializable compatible (fromJson / toJson)
• Generates copyWith method
• Optional snake_case → camelCase conversion
• Output as separate .dart files
• Configurable output directory
• CLI help included

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Getting Started

Install

Activate globally via Dart:

dart pub global activate json2dartgen

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Usage

dart run json2dartgen <input.json> [options]

Options:

Flag	Description
-c, --camel-case	Convert snake_case JSON keys to camelCase field names
-o, --output-dir	Output directory for .dart files (default: current directory)
-n, --nullable-copywith	Generate nullable copyWith method with ability to null non-nullables
-h, --help	Show usage instructions

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Examples

Generate models in the current directory:

dart run json2dartgen api_response.json

Generate models with camelCase fields:

dart run json2dartgen api_response.json --camel-case

Generate models in a specific directory:

dart run json2dartgen api_response.json --camel-case --output-dir lib/models

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Generated Code Example

Input JSON:

{
  "building_id": 1130,
  "floor_count": 5,
  "location_name": "North Wing"
}

Generated Dart model:

import 'package:json_annotation/json_annotation.dart';

part 'root.g.dart';

@JsonSerializable()
class Root {
  @JsonKey(name: 'building_id')
  final int buildingId;

  @JsonKey(name: 'floor_count')
  final int floorCount;

  @JsonKey(name: 'location_name')
  final String locationName;

  const Root({
    required this.buildingId,
    required this.floorCount,
    required this.locationName,
  });

  Root copyWith({
    int? buildingId,
    int? floorCount,
    String? locationName,
  }) {
    return Root(
      buildingId: buildingId ?? this.buildingId,
      floorCount: floorCount ?? this.floorCount,
      locationName: locationName ?? this.locationName,
    );
  }

  factory Root.fromJson(Map<String, dynamic> json) => _$RootFromJson(json);
  Map<String, dynamic> toJson() => _$RootToJson(this);
}

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Notes

• Ensure json_annotation and json_serializable are in your pubspec.yaml dependencies for Flutter/Dart projects.
• Run build_runner to generate the .g.dart files:

dart run build_runner build --delete-conflicting-outputs

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License

This project is licensed under the MIT License - see the LICENSE file for details.

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Author

Saleh Talebizadeh https://salehtz.ir