json_to_toon 1.0.0

A Flutter/Dart package for converting between JSON and TOON (Token-Oriented Object Notation) formats. TOON is a compact, human-readable encoding optimized for LLM prompts.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:json_to_toon/json_to_toon.dart';
import 'dart:convert';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'JSON to TOON Converter',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const ConverterPage(),
    );
  }
}

class ConverterPage extends StatefulWidget {
  const ConverterPage({super.key});

  @override
  State<ConverterPage> createState() => _ConverterPageState();
}

class _ConverterPageState extends State<ConverterPage> {
  final TextEditingController _inputController = TextEditingController();
  final TextEditingController _outputController = TextEditingController();
  final ToonConverter _converter = ToonConverter();
  
  bool _isJsonToToon = true;
  String _errorMessage = '';

  @override
  void initState() {
    super.initState();
    // Set example JSON
    _inputController.text = '''{
  "context": {
    "task": "Our favorite hikes",
    "location": "Boulder",
    "season": "spring_2025"
  },
  "friends": ["ana", "luis", "sam"],
  "hikes": [
    {
      "id": 1,
      "name": "Blue Lake Trail",
      "distanceKm": 7.5,
      "elevationGain": 320,
      "companion": "ana",
      "wasSunny": true
    },
    {
      "id": 2,
      "name": "Ridge Overlook",
      "distanceKm": 9.2,
      "elevationGain": 540,
      "companion": "luis",
      "wasSunny": false
    }
  ]
}''';
  }

  void _convert() {
    setState(() {
      _errorMessage = '';
      try {
        if (_isJsonToToon) {
          // JSON to TOON
          final toon = _converter.jsonToToon(_inputController.text);
          _outputController.text = toon;
        } else {
          // TOON to JSON
          final json = _converter.toonToJson(_inputController.text);
          // Pretty print JSON
          final decoded = jsonDecode(json);
          final encoder = JsonEncoder.withIndent('  ');
          _outputController.text = encoder.convert(decoded);
        }
      } catch (e) {
        _errorMessage = 'Error: $e';
        _outputController.text = '';
      }
    });
  }

  void _swap() {
    setState(() {
      _isJsonToToon = !_isJsonToToon;
      // Swap input and output
      final temp = _inputController.text;
      _inputController.text = _outputController.text;
      _outputController.text = temp;
      _errorMessage = '';
    });
  }

  void _clear() {
    setState(() {
      _inputController.clear();
      _outputController.clear();
      _errorMessage = '';
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: const Text('JSON ↔ TOON Converter'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // Mode indicator
            Card(
              color: Theme.of(context).colorScheme.primaryContainer,
              child: Padding(
                padding: const EdgeInsets.all(12.0),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Text(
                      _isJsonToToon ? 'JSON → TOON' : 'TOON → JSON',
                      style: Theme.of(context).textTheme.titleLarge?.copyWith(
                        color: Theme.of(context).colorScheme.onPrimaryContainer,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(width: 16),
                    IconButton(
                      icon: const Icon(Icons.swap_horiz),
                      onPressed: _swap,
                      tooltip: 'Swap direction',
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 16),
            
            // Input field
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    _isJsonToToon ? 'JSON Input:' : 'TOON Input:',
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                  const SizedBox(height: 8),
                  Expanded(
                    child: TextField(
                      controller: _inputController,
                      maxLines: null,
                      expands: true,
                      decoration: const InputDecoration(
                        border: OutlineInputBorder(),
                        hintText: 'Enter your data here...',
                      ),
                      style: const TextStyle(fontFamily: 'monospace'),
                    ),
                  ),
                ],
              ),
            ),
            
            const SizedBox(height: 16),
            
            // Action buttons
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                ElevatedButton.icon(
                  onPressed: _convert,
                  icon: const Icon(Icons.transform),
                  label: const Text('Convert'),
                ),
                const SizedBox(width: 16),
                OutlinedButton.icon(
                  onPressed: _clear,
                  icon: const Icon(Icons.clear),
                  label: const Text('Clear'),
                ),
              ],
            ),
            
            const SizedBox(height: 16),
            
            // Error message
            if (_errorMessage.isNotEmpty)
              Card(
                color: Theme.of(context).colorScheme.errorContainer,
                child: Padding(
                  padding: const EdgeInsets.all(12.0),
                  child: Text(
                    _errorMessage,
                    style: TextStyle(
                      color: Theme.of(context).colorScheme.onErrorContainer,
                    ),
                  ),
                ),
              ),
            
            if (_errorMessage.isNotEmpty) const SizedBox(height: 16),
            
            // Output field
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    _isJsonToToon ? 'TOON Output:' : 'JSON Output:',
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                  const SizedBox(height: 8),
                  Expanded(
                    child: TextField(
                      controller: _outputController,
                      maxLines: null,
                      expands: true,
                      readOnly: true,
                      decoration: const InputDecoration(
                        border: OutlineInputBorder(),
                        hintText: 'Output will appear here...',
                      ),
                      style: const TextStyle(fontFamily: 'monospace'),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  @override
  void dispose() {
    _inputController.dispose();
    _outputController.dispose();
    super.dispose();
  }
}