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json5_model

Convert JSON files to Dart model classes with a single command

An improved version of json_model that supports nested JSON parsing, JSON5 files, and fixes several bugs. Note: The original @meta functionality from json_model is not supported.

Installation

dependencies:
  json_annotation: ^4.9.0
  copy_with_extension: ^6.0.1
  equatable: ^2.0.7
  autoequal: ^0.9.1

dev_dependencies:
  json5_model: ^3.0.0
  json_serializable: ^6.9.5
  autoequal_gen: ^0.9.5
  copy_with_extension_gen: ^6.0.1
  build_runner: ^2.4.15

Usage

1. Create a directory named "jsons" in your project root
2. Create or copy JSON files into the "jsons" directory
3. Examples:

# Custom paths
flutter pub run json5_model --src=lib/data/json --dist=lib/data/model

# Use RegExp to extract class name prefix from filenames (e.g. remove "_response" suffix)
flutter pub run json5_model  --src=lib/data/json --dist=lib/test/json --prefix-regexp "(.+?)_response$"

# Keep source files
flutter pub run json5_model --src=lib/data/json --dist=lib/data/model --keepsource

# Restore files
flutter pub run json5_model --src=lib/data/json --restore

New Features

File Restoration Command

Use the --restore parameter to restore all renamed JSON files:

flutter pub run json5_model --restore

Keep Source Files

Add the --keepsource parameter to prevent automatic renaming of JSON files:

flutter pub run json5_model --keepsource

Global Command Parameters

Parameter	Description	Default Value
--src	Specify JSON source directory	./jsons
--dist	Specify output directory	lib/models
--nocopywith	Disable copyWith method generation	false
--noautoequal	Disable equality comparison generation	false
--keepsource	Keep original JSON files (don't add _ prefix) after generation	false
--restore	Restore all renamed JSON files	false
--clean	Clean generated files	false
--no-file-prefix	Disable auto-adding class name prefixes (may cause name conflicts)	false
--prefix-regexp	Apply RegExp to filename to extract class name prefix	(.+?)

How It Works

1. Smart Type Inference
   Automatically detects and merges these type characteristics:

   • Numeric type promotion (int → double)
   • Handles nested objects and lists
   • Automatic null safety handling
   • Merges fields from multiple JSON structures

2. File Management

   • By default adds "_" prefix to source JSON files after generation (can be disabled with --keepsource)
   • Use --restore to batch restore renamed files

3. Advanced Features

   // Auto-generated extension methods
   List<Github> githubListFormJson(List json) => ... 
   
   // Empty object construction
   factory Github.emptyInstance() => Github(...);
   
   // Deep copy support
   Github newObj = oldObj.copyWith(id: 123);

Example JSON → Dart Conversion

Input JSON:

{
  "scores": [
    90,
    85.5,
    null
  ],
  "users": [
    {
      "name": "Alice",
      "age": 25
    },
    {
      "name": "Bob",
      "height": 175.5
    }
  ]
}

Generated Dart snippet:

// Automatic numeric type and nullable handling
List<double?> scores;

// Merges Map fields from different structures
class UsersItem {
  String? name;
  int? age;
  double? height;

  factory UsersItem.fromJson(Map<String, dynamic> json) =>

  ...
}

Best Practices

1. Version Control
   Recommend including original JSON files in version control (with proper data sanitization)

2. CI Integration
   Add generation command to your CI pipeline:

   # GitHub Actions example
   - name: Generate models
     run: flutter pub run json5_model

3. Mixed Type Handling
   When encountering incompatible types:

   // Automatically falls back to dynamic type
   List<dynamic> complexList;

4. Custom Configuration
   Combine parameters for customized generation:

   # Disable autoequal and copywith generation
   flutter pub run json5_model --noautoequal --nocopywith

Example:

flutter pub run json5_model --src=lib/data/json

json:

{
  "id": 1296269,
  "node_id": "MDEwOlJlcG9zaXRvcnkxMjk2MjY5",
  "owner": {
    "login": "octocat",
  },
  "private": false,
  "topics": [
    "octocat",
    "atom",
    "electron",
    "api"
  ],
  "permissions": {
    "admin": false,
    "push": false,
    "pull": true
  },
  "security_and_analysis": {
    "advanced_security": {
      "status": "enabled"
    },
    "secret_scanning": {
      "status": "enabled"
    },
    "secret_scanning_push_protection": {
      "status": "disabled"
    }
  }
}

Dart:

import 'package:json_annotation/json_annotation.dart';
import 'package:copy_with_extension/copy_with_extension.dart';
import 'package:equatable/equatable.dart';
import 'package:autoequal/autoequal.dart';

part 'github.g.dart';

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class Github
    with EquatableMixin {

  Github({required this.id,
    required this.nodeId,
    required this.owner,
    required this.private,
    required this.topics,
    required this.permissions,
    required this.securityAndAnalysis});

  @JsonKey(name: "id", defaultValue: 0)
  final int id;

  @JsonKey(name: "node_id", defaultValue: "")
  final String nodeId;

  @JsonKey(name: "owner", defaultValue: Owner.emptyInstance)
  final Owner owner;

  @JsonKey(name: "private", defaultValue: false)
  final bool private;

  @JsonKey(name: "topics", defaultValue: [])
  final List<String> topics;

  @JsonKey(name: "permissions", defaultValue: Permissions.emptyInstance)
  final Permissions permissions;

  @JsonKey(name: "security_and_analysis", defaultValue: SecurityAndAnalysis.emptyInstance)
  final SecurityAndAnalysis securityAndAnalysis;


  factory Github.fromJson(Map<String, dynamic> json) => _$GithubFromJson(json);

  Map<String, dynamic> toJson() => _$GithubToJson(this);

  factory Github.emptyInstance() =>
      Github(id: 0,
      nodeId: "",
      owner: Owner.emptyInstance(),
      private: false,
      topics: [],
      permissions: Permissions.emptyInstance(),
      securityAndAnalysis: SecurityAndAnalysis.emptyInstance());

  @override
  List<Object?> get props => _$props;
}

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class Owner
    with EquatableMixin {

  Owner({required this.login});

  @JsonKey(name: "login", defaultValue: "")
  final String login;


  factory Owner.fromJson(Map<String, dynamic> json) => _$OwnerFromJson(json);

  Map<String, dynamic> toJson() => _$OwnerToJson(this);

  factory Owner.emptyInstance() => Owner(login: "");

  @override
  List<Object?> get props => _$props;
}

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class Permissions
    with EquatableMixin {

  Permissions({required this.admin,
    required this.push,
    required this.pull});

  @JsonKey(name: "admin", defaultValue: false)
  final bool admin;

  @JsonKey(name: "push", defaultValue: false)
  final bool push;

  @JsonKey(name: "pull", defaultValue: false)
  final bool pull;


  factory Permissions.fromJson(Map<String, dynamic> json) => _$PermissionsFromJson(json);

  Map<String, dynamic> toJson() => _$PermissionsToJson(this);

  factory Permissions.emptyInstance() => Permissions(admin: false, push: false, pull: false);

  @override
  List<Object?> get props => _$props;
}

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class AdvancedSecurity
    with EquatableMixin {

  AdvancedSecurity({required this.status});

  @JsonKey(name: "status", defaultValue: "")
  final String status;


  factory AdvancedSecurity.fromJson(Map<String, dynamic> json) => _$AdvancedSecurityFromJson(json);

  Map<String, dynamic> toJson() => _$AdvancedSecurityToJson(this);

  factory AdvancedSecurity.emptyInstance() => AdvancedSecurity(status: "");

  @override
  List<Object?> get props => _$props;
}

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class SecretScanning
    with EquatableMixin {

  SecretScanning({required this.status});

  @JsonKey(name: "status", defaultValue: "")
  final String status;


  factory SecretScanning.fromJson(Map<String, dynamic> json) => _$SecretScanningFromJson(json);

  Map<String, dynamic> toJson() => _$SecretScanningToJson(this);

  factory SecretScanning.emptyInstance() => SecretScanning(status: "");

  @override
  List<Object?> get props => _$props;
}

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class SecretScanningPushProtection
    with EquatableMixin {

  SecretScanningPushProtection({required this.status});

  @JsonKey(name: "status", defaultValue: "")
  final String status;


  factory SecretScanningPushProtection.fromJson(Map<String, dynamic> json) =>
      _$SecretScanningPushProtectionFromJson(json);

  Map<String, dynamic> toJson() => _$SecretScanningPushProtectionToJson(this);

  factory SecretScanningPushProtection.emptyInstance() => SecretScanningPushProtection(status: "");

  @override
  List<Object?> get props => _$props;
}

@CopyWith()
@Autoequal()
@JsonSerializable(explicitToJson: true)
class SecurityAndAnalysis
    with EquatableMixin {

  SecurityAndAnalysis({required this.advancedSecurity,
    required this.secretScanning,
    required this.secretScanningPushProtection});

  @JsonKey(name: "advanced_security", defaultValue: AdvancedSecurity.emptyInstance)
  final AdvancedSecurity advancedSecurity;

  @JsonKey(name: "secret_scanning", defaultValue: SecretScanning.emptyInstance)
  final SecretScanning secretScanning;

  @JsonKey(name: "secret_scanning_push_protection",
      defaultValue: SecretScanningPushProtection.emptyInstance)
  final SecretScanningPushProtection secretScanningPushProtection;


  factory SecurityAndAnalysis.fromJson(Map<String, dynamic> json) =>
      _$SecurityAndAnalysisFromJson(json);

  Map<String, dynamic> toJson() => _$SecurityAndAnalysisToJson(this);

  factory SecurityAndAnalysis.emptyInstance() =>
      SecurityAndAnalysis(advancedSecurity: AdvancedSecurity.emptyInstance(),
          secretScanning: SecretScanning.emptyInstance(),
          secretScanningPushProtection: SecretScanningPushProtection.emptyInstance());

  @override
  List<Object?> get props => _$props;
}