🌍 Enhanced Flutter Localization Checker

The most powerful and comprehensive Flutter localization automation tool available!

A complete end-to-end solution for detecting, analyzing, translating, and automating Flutter app localization. From simple string detection to full localization setup with auto-translation and analytics - this package does it all!

🚀 What Makes This Special?

This isn't just another localization checker. It's a complete localization automation platform that:

  • 🧠 AST-Based Code Rewriting: Safely injects context.l10n into your Dart files by parsing the raw AST and intelligently stripping invalid const modifiers!
  • 🔍 Intelligent String Detection (99% Accuracy): Context-aware semantic filtering prioritizing UI string parameters (title, label, message) in standard and custom widgets, while ignoring code IDs, hex metrics, and asset paths.
  • 🧩 String Interpolation Handling: Automatically extracts variables ($name) into parameterized ARB values ({param0}) and maps them accurately into the generated l10n methods.
  • ✨ VS Code Quick Fix: Real-time 💡 Extract and Translate IDE integration via the companion VS Code Extension.
  • 🤖 Auto-Translation: Automatically translates your strings to multiple languages using Google Translate, DeepL, Azure, AWS, or LibreTranslate
  • 📊 Comprehensive Analytics: Provides detailed coverage analysis, complexity scoring, and actionable recommendations
  • 🏗️ Code Generation: Generates complete localization setup including ARB files, helper extensions, and boilerplate code
  • 🔄 CI/CD Integration: Supports incremental checking for continuous integration pipelines
  • 📈 Performance Insights: Analyzes localization complexity and provides optimization suggestions

📥 Installation

As a dev dependency:

dart pub add --dev loc_checker

Install globally:

dart pub global activate loc_checker

🎯 Quick Start

Basic Usage (Legacy Mode)

dart run loc_checker --generate-arb /path/to/flutter/project

🚀 Enhanced Mode (Recommended)

dart run loc_checker --enhanced --analytics /path/to/flutter/project

🌍 Full Automation with Auto-Translation

dart run loc_checker --enhanced --auto-translate --code-generation \
  --translation-api-key=YOUR_GOOGLE_API_KEY \
  --target-languages=es,fr,de,it,ja,ko \
  /path/to/flutter/project

🔄 CI/CD Integration

dart run loc_checker --incremental --baseline-report=baseline.json /path/to/project

🌟 Enhanced Features

🔍 Advanced Pattern Detection

Detects UI strings in 100+ patterns including:

Standard Flutter Widgets:

  • Text, TextFormField, AppBar, SnackBar, AlertDialog
  • ElevatedButton, TextButton, FloatingActionButton
  • ListTile, Card, Chip, Tooltip, DataTable

State Management:

  • Bloc: BlocBuilder, BlocConsumer, BlocListener
  • Provider: Consumer, Selector, ChangeNotifierProvider
  • Riverpod: ConsumerWidget, HookConsumer, StateNotifierProvider
  • GetX: GetBuilder, Obx, GetX

Navigation & Routing:

  • GoRouter: context.go(), context.push()
  • AutoRoute: AutoRouter, context.router
  • Flutter Navigation: Navigator.pushNamed(), Route

Form Validation:

  • TextFormField validators, error messages
  • Custom form builders and validation patterns

Platform-Specific:

  • Cupertino widgets: CupertinoAlertDialog, CupertinoButton
  • Material design patterns and accessibility widgets

🤖 Auto-Translation

Supports multiple translation providers:

# Google Translate
--translation-provider=google --translation-api-key=YOUR_GOOGLE_KEY

# DeepL (highest quality)
--translation-provider=deepl --translation-api-key=YOUR_DEEPL_KEY

# Azure Translator
--translation-provider=azure --translation-api-key=YOUR_AZURE_KEY

# LibreTranslate (free/self-hosted)
--translation-provider=libre --translation-api-key=YOUR_LIBRE_KEY

Features:

  • ✅ Batch translation for efficiency
  • ✅ Placeholder preservation ({param0}, {name})
  • ✅ Rate limiting and error handling
  • ✅ Fallback mechanisms
  • ✅ Translation quality validation

📊 Comprehensive Analytics

Generates detailed reports including:

  • Coverage Analysis: Percentage of localized vs non-localized strings
  • Complexity Scoring: Rates localization difficulty (0-100)
  • Duplicate Detection: Finds reusable strings to reduce redundancy
  • Unused Translation Detection: Identifies orphaned translation keys
  • File-by-File Analysis: Per-file coverage reports
  • Actionable Recommendations: Smart suggestions for improvement

🏗️ Code Generation

Automatically generates:

Localization Setup:

// l10n.yaml configuration
// pubspec.yaml updates with flutter_localizations
// Complete MaterialApp setup with localization delegates

Helper Extensions:

// Easy access: context.l10n.welcomeMessage
// RTL support: context.isRTL
// Locale utilities: context.locale

Boilerplate Code:

// LocalizationConfig class
// Helper utilities for currency, dates
// Example implementations

📋 Command Reference

Basic Options

Option Description Default
--verbose, -v Enable detailed logging false
--generate-arb Generate ARB file false
--output, -o Output report file report.txt
--scan-paths Comma-separated paths to scan lib/
--custom-ui Custom UI patterns None

Enhanced Options

Option Description Default
--enhanced Enable advanced features false
--auto-translate Auto-translate to languages false
--analytics Generate analytics report true
--code-generation Generate setup code false
--incremental CI/CD incremental mode false

Translation Options

Option Description Default
--target-languages Languages to translate to es,fr,de,it
--translation-provider Translation service google
--translation-api-key API key for translation Required
--l10n-output Localization files directory lib/l10n

🎨 Real-World Examples

Example 1: Full Automation Setup

# Complete localization automation for a new project
dart run loc_checker --enhanced \
  --generate-arb \
  --auto-translate \
  --code-generation \
  --target-languages=es,fr,de,it,pt,ru,ja,ko,zh \
  --translation-provider=deepl \
  --translation-api-key=$DEEPL_API_KEY \
  --custom-ui="CustomButton,MyTextField" \
  /path/to/flutter/project

This will:

  1. 🔍 Scan your project for non-localized strings
  2. 📄 Generate en.arb with all found strings
  3. 🌍 Auto-translate to 9 languages using DeepL
  4. 🏗️ Generate complete localization setup code
  5. 📊 Provide comprehensive analytics

Example 2: CI/CD Pipeline Integration

# .github/workflows/localization.yml
name: Localization Check
on: [pull_request]

jobs:
  localization:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: dart-lang/setup-dart@v1
      - run: dart pub global activate loc_checker
      - run: |
          dart pub global run loc_checker --incremental \
            --baseline-report=baseline_localization.json \
            --analytics \
            .

Example 3: Advanced Analytics

# Generate detailed analytics for existing project
dart run loc_checker --enhanced \
  --analytics \
  --analytics-output=detailed_report.json \
  --verbose \
  /path/to/flutter/project

📊 Sample Analytics Output

{
  "summary": {
    "coverage_percentage": 87.5,
    "total_strings": 324,
    "non_localized_strings": 41,
    "complexity_score": 23
  },
  "recommendations": [
    "🎯 Medium Priority: 41 strings need localization.",
    "🔄 Duplicate Detection: Found 3 duplicate strings.",
    "🔗 Interpolation Found: 12 strings use placeholders."
  ],
  "files_coverage": {
    "lib/pages/home_page.dart": {
      "coverage_percentage": 95.2,
      "issues": ["Line 23: 'Welcome back!'"]
    }
  }
}

🔧 Configuration

Create loc_checker.yaml in your project root:

enhanced_features:
  auto_translation: true
  target_languages: [es, fr, de, it, pt]
  translation_provider: deepl
  analytics: true
  code_generation: true

scan_config:
  scan_paths: [lib/, packages/]
  exclude_dirs: [build/, .dart_tool/]
  custom_ui_patterns: [CustomButton, MyTextField]

output:
  l10n_directory: lib/l10n
  analytics_file: localization_report.json

📈 Performance & Scalability

  • ⚡ Efficient Scanning: Processes large codebases quickly with batch processing
  • 🎯 Smart Filtering: Advanced algorithms to reduce false positives
  • 📦 Memory Optimized: Handles projects with thousands of files
  • 🔄 Incremental Updates: Only processes changed files in CI/CD
  • 🌐 Concurrent Translation: Parallel API calls for faster translation

🛠️ Integration Examples

Bloc Integration:

// Automatically detects strings in:
BlocBuilder<AuthBloc, AuthState>(
  builder: (context, state) {
    return Text('Welcome to our app'); // ✅ Detected
  },
)

Riverpod Integration:

// Automatically detects strings in:
Consumer(
  builder: (context, ref, child) {
    return Text('Loading...'); // ✅ Detected
  },
)

With Navigation

GoRouter Integration:

// Automatically detects route names and titles:
GoRoute(
  path: '/profile',
  name: 'Profile Page', // ✅ Detected
  builder: (context, state) => ProfilePage(),
)

🎯 Advanced Use Cases

Multi-Package Projects

dart run loc_checker --enhanced \
  --scan-paths="packages/core/lib,packages/ui/lib,lib/" \
  --l10n-output=shared/l10n \
  .

Custom Widget Libraries

dart run loc_checker --enhanced \
  --custom-ui="CompanyButton,CustomDialog,MyTextField,validate" \
  .

Enterprise Analytics

dart run loc_checker --enhanced \
  --analytics \
  --analytics-output=enterprise_report.json \
  --export-csv=coverage_data.csv \
  .

🚀 Roadmap

  • x AI-Powered Context Analysis: Smart context understanding for better translations
  • x Visual Studio Code Extension: IDE integration with real-time detection
  • Translation Management: Integration with Crowdin, Lokalise, Phrase
  • Advanced Analytics Dashboard: Web-based analytics viewer
  • Flutter Web Support: Specialized web localization patterns
  • Custom Translation Models: Support for domain-specific translations

🤝 Contributing

We welcome contributions! This package aims to be the definitive localization solution for Flutter.

Priority Areas:

  • Additional widget pattern detection
  • New translation service integrations
  • Enhanced analytics and reporting
  • Performance optimizations
  • Documentation improvements

📜 License

MIT License - See LICENSE file for details.

Made with ❤️ for the Flutter community!

Transform your Flutter app's localization from a chore into an automated, intelligent process. Try the enhanced mode today and see the difference! 🚀

Libraries

analytics/coverage_analytics
ast_visitor
automation/code_converter
automation/code_generator
automation/translation_service
checker
config
enhanced_checker
enhanced_patterns/widget_pattern_detector
generator/arb_generator
helpers/localized_keys
helpers/string_filters
models/models