translate_gen Package

This package provides tools to assist with translation tasks in Flutter projects, including preparing configuration files, extracting translatable strings, and replacing them based on a configuration. It supports multiple AI translation providers including Gemini and DeepSeek R1.

Installation

Add the following to your pubspec.yaml:

dev_dependencies:
  translate_gen: ^1.0.6

Run flutter pub get to install the package.

Commands

1. Prepare Configuration

The prepare command generates a configuration file (prepare.dart) and an empty replace.json file under the assets/translate_gen directory. You can choose between two configuration types: normal or easy (for easy_localization package).

Command:

flutter pub run translate_gen:prepare

Command with Options:

# For normal translation setup
flutter pub run translate_gen:prepare --type normal

# For easy_localization package setup (default)
flutter pub run translate_gen:prepare --type easy

Output:

• Creates assets/translate_gen/prepare.dart with the following content:

For Easy Localization (default):

import 'package:translate_gen/src/extract/exception_rules.dart';
import 'package:translate_gen/src/translate/translation_provider.dart';

final translationConfig = ExceptionRules(
  textExceptions: ['import'],
  lineExceptions: ['line_start_to_skip'],
  contentExceptions: ['substring_to_skip'],
  folderExceptions: [''],
  extractFilter: [
    RegExp(r"'[^']*[\u0600-\u06FF][^']*'"),
    RegExp(r'"[^"]*[\u0600-\u06FF][^"]*"')
  ],
  import: [
    "import 'package:easy_localization/easy_localization.dart';",
    "import 'package:$projectName/core/app_strings/locale_keys.dart';"
  ],
  key: "LocaleKeys.{key}.tr()",
  keyWithVariable: "LocaleKeys.{key}.tr(args: [{args}])",
  translate: true,
  extractOutput: 'replace.json',
  aiKey: '', // Required only when using TranslationProvider.gemini
  aiModel: TranslationProvider.deepseekR1, // Available options: gemini, deepseekR1
);

For Normal Translation:

import 'package:translate_gen/src/extract/exception_rules.dart';
import 'package:translate_gen/src/translate/translation_provider.dart';

final translationConfig = ExceptionRules(
  textExceptions: ['import'],
  lineExceptions: ['line_start_to_skip'],
  contentExceptions: ['substring_to_skip'],
  folderExceptions: [''],
  extractFilter: [
    RegExp(r"'[^']*[\u0600-\u06FF][^']*'"),
    RegExp(r'"[^"]*[\u0600-\u06FF][^"]*"')
  ],
  import: [],
  key: "s.current.{key}",
  keyWithVariable: "s.current.{key}({args})", //not work in flutter_localization only in easy_localization
  translate: true,
  extractOutput: 'replace.json',
  aiKey: '', // Required only when using TranslationProvider.gemini
  aiModel: TranslationProvider.deepseekR1, // Available options: gemini, deepseekR1
);

• Creates assets/translate_gen/replace.json as an empty JSON file:

{}

Purpose:

This command sets up the necessary configuration for the translation process, defining rules for exceptions, filters for extracting translatable strings (e.g., Arabic text), and the format for translation keys.

• Easy type: Configured for use with the easy_localization package, including the necessary import and .tr() method calls
• Normal type: Basic configuration without external package dependencies, suitable for custom translation implementations

AI Translation Configuration

The package supports multiple AI translation providers:

Available AI Models

• TranslationProvider.deepseekR1: DeepSeek R1 model (default)
• TranslationProvider.gemini: Google Gemini model

Gemini Configuration

When using Google Gemini as your AI model, you must provide a valid API key:

1. Set the aiModel to TranslationProvider.gemini
2. Add your Gemini API key to the aiKey field

Example configuration for Gemini:

final translationConfig = ExceptionRules(
  // ... other configuration ...
  aiKey: 'your-gemini-api-key-here',
  aiModel: TranslationProvider.gemini,
);

Note: The aiKey field is only required when using TranslationProvider.gemini and translation is enabled. You can leave it empty when using other AI models.

API Key Sources

• Gemini: Get your API key from Google AI Studio
• Other models: Get your API key from OpenRouter.

2. Extract Translatable Strings

The extract command scans the specified path (or default path) for translatable strings and generates key-value pairs to be stored in replace.json.

Command:

flutter pub run translate_gen:extract [--path='lib/core']

Parameters:

• --path: Optional. Specifies the directory to scan for translatable strings. Defaults to lib/core if not provided.

Output:

• Updates assets/translate_gen/replace.json with extracted strings in the format:

{
  "key1": "translatable string 1",
  "key2": "translatable string 2"
}

Purpose: This command identifies strings (e.g., Arabic text matching the regex patterns in prepare.dart) and prepares them for translation by storing them in replace.json. The AI model specified in the configuration will be used for automatic translation.

3. Replace Strings

The replace command replaces strings in the specified path (or default path) with translation keys based on the content of replace.json.

Command:

flutter pub run translate_gen:replace [--path='lib/core']

Parameters:

• --path: Optional. Specifies the directory where strings will be replaced. Defaults to lib/core if not provided.

Behavior:

• Reads replace.json to get key-value pairs
• Replaces matching strings in the specified path with translation keys in the format defined in prepare.dart (e.g., LocaleKeys.{key}.tr() or LocaleKeys.{key}.tr(args: [{args}]) for strings with variables)
• Adds necessary import statements (e.g., import 'package:easy_localization/easy_localization.dart';) to files as specified in the configuration

Purpose: This command automates the replacement of hard-coded strings with translation keys, enabling easy localization using the easy_localization package.

Directory Structure

After running the prepare command, the following structure is created:

assets/
└── translate_gen/
    ├── prepare.dart
    └── replace.json

Configuration Parameters

ExceptionRules Parameters

Parameter	Type	Description
textExceptions	List<String>	Text patterns to exclude from extraction
lineExceptions	List<String>	Line patterns to skip during extraction
contentExceptions	List<String>	Content substrings to skip
folderExceptions	List<String>	Folders to exclude from scanning
extractFilter	List<RegExp>	Regex patterns to match translatable strings
import	List<String>	Import statements to add to files
key	String	Format for translation keys
keyWithVariable	String	Format for translation keys with variables
translate	bool	Enable/disable automatic translation
extractOutput	String	Output file for extracted strings
aiKey	String	API key for Gemini (required only for Gemini)
aiModel	TranslationProvider	AI model to use for translation

Notes

• The extractFilter in prepare.dart is configured to detect Arabic strings (Unicode range \u0600-\u06FF). Modify the regex patterns to support other languages if needed
• The replace.json file is overwritten during the extract command, so back up any manual changes before running it
• Before running the replace command, make sure replace.json has the following content (with at least an empty object {})
• When using Gemini, ensure you have a valid API key from Google AI Studio
• DeepSeek R1 is the default AI model and doesn't require additional API key configuration
• The AI translation feature requires an internet connection to communicate with the selected AI provider