Flutter Universal String Extractor

License: MIT

A powerful, interactive command-line script to automate the extraction of hard-coded strings from your Flutter project for localization. This tool scans your Dart files, replaces strings with a localization key, and updates your JSON language files accordingly.

The Problem

Manually finding every hard-coded string, replacing it with a .tr() extension, and adding the key to your JSON files is tedious, time-consuming, and prone to errors. This process slows down development, especially in large projects.

The Solution

This script automates the entire process. It intelligently identifies user-facing strings, skips code-like or debug strings, and prepares your project for translation into multiple languages, saving you hours of manual work.

Features

  • Interactive CLI: User-friendly prompts guide you through the process.
  • Automated Replacement: Replaces string literals like "Hello World" with 'Hello World'.tr().
  • Smart String Detection: Intelligently skips strings that are not meant for translation (e.g., paths, URLs, interpolated strings like "$name", debug logs).
  • JSON File Management: Automatically creates or updates your .json language files.
    • Preserves existing translations.
    • Adds new keys to your base language file (e.g., en.json).
    • Adds placeholder keys to target language files (e.g., ar.json, fr.json).
  • Package Support: Works with both easy_localization and localize_and_translate.
  • Safe and Flexible: Scans only the directories you specify and requires confirmation before modifying any files.

Prerequisites

  • Dart SDK installed on your machine.
  • A Flutter project using either easy_localization or localize_and_translate.

How to Use

  1. Save the Script: Save the extract_strings.dart script to the root directory of your Flutter project.

  2. Run the Script: Open your terminal in the project root and run the following command:

    extract_strings

  3. Follow the Prompts: The script will ask you a series of questions:

    • Which localization package you are using.
    • Your project's base language (e.g., en).
    • Your target languages (e.g., ar, fr).
    • Which folders inside lib/ to scan (or * for all).

    Script in Action 4. Confirm and Execute: The script will show a summary of the actions it's about to take. Type y to proceed.

Example

Before:

// in lib/screens/home_screen.dart
class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Welcome Home"),
      ),
      body: Center(
        child: Text("This is the home page."),
      ),
    );
  }
}

After Running the Script:

// in lib/screens/home_screen.dart
import 'package:easy_localization/easy_localization.dart';

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Welcome Home'.tr()),
      ),
      body: Center(
        child: Text('This is the home page.'.tr()),
      ),
    );
  }
}

Result in assets/lang/en.json:

{
  "This is the home page.": "This is the home page.",
  "Welcome Home": "Welcome Home"
}

Result in assets/lang/ar.json:

{
  "This is the home page.": "",
  "Welcome Home": ""
}

Configuration

You can modify the constants at the top of the extract_strings.dart script to change the default directories:

const String searchDir = 'lib';
const String langAssetsDir = 'assets/lang';

License

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

Libraries