Internationalization Helper

Helps manage internationalization (i18n) and localization (l10n) in multi-language applications.

When to Use

•User requests i18n support
•Adding new languages
•Finding untranslated strings
•Managing translation files
•User mentions "translation", "i18n", "l10n", "locale"

Instructions

1. Detect i18n Framework

JavaScript/React:

•react-i18next
•react-intl (FormatJS)
•i18next
•LinguiJS

Vue:

•vue-i18n

Python:

•gettext
•Django i18n
•Flask-Babel

Ruby/Rails:

•I18n gem (built-in)

Look for imports, config files, or translation directories.

2. Find Hardcoded Strings

Search for untranslated text:

javascript

// Bad: Hardcoded
<button>Submit</button>
<p>Welcome, {user.name}!</p>

// Good: Translated
<button>{t('common.submit')}</button>
<p>{t('welcome.message', { name: user.name })}</p>

Search patterns:

•Strings in JSX/template tags
•Alert/error messages
•Form labels and placeholders
•Button text
•Validation messages

Exclude: code comments, console.log, test strings

3. Extract to Translation Files

React-i18next format (JSON):

json

{
  "common": {
    "submit": "Submit",
    "cancel": "Cancel"
  },
  "welcome": {
    "message": "Welcome, {{name}}!"
  }
}

Gettext format (.po):

msgid "submit_button"
msgstr "Submit"

msgid "welcome_message"
msgstr "Welcome, %(name)s!"

4. Organize Translation Keys

Best practices:

•Namespace by feature: users.profile.title
•Group common strings: common.buttons.save
•Describe context, not content: errors.login.invalid not errors.wrong_password
•Consistent naming convention

5. Check Translation Coverage

Compare locale files to find missing translations:

code

en.json: 150 keys
es.json: 142 keys (missing 8)
fr.json: 150 keys ✓

Missing in es.json:
- users.profile.bio
- settings.privacy.title
[...]

6. Handle Pluralization

Different languages have different plural rules:

javascript

// react-i18next
t('items', { count: 0 })  // "0 items"
t('items', { count: 1 })  // "1 item"
t('items', { count: 5 })  // "5 items"

// Translation file
{
  "items_zero": "{{count}} items",
  "items_one": "{{count}} item",
  "items_other": "{{count}} items"
}

7. Date, Time, Number Formatting

Use locale-aware formatting:

javascript

// Numbers
const price = new Intl.NumberFormat('en-US', {
  style: 'currency',
  currency: 'USD'
}).format(29.99);

// Dates
const date = new Intl.DateTimeFormat('fr-FR').format(new Date());

8. RTL (Right-to-Left) Support

For Arabic, Hebrew:

•CSS: direction: rtl;
•HTML: <html dir="rtl">
•Logical properties: margin-inline-start instead of margin-left

9. Generate Translation Template

Create template for new locale:

bash

# Copy keys from base language, empty values
cp locales/en.json locales/de.json
# Mark for translation

10. Best Practices

•Keep translations in separate files
•Use keys, not source text as keys
•Provide context to translators
•Test with long strings (German often longer)
•Use ICU MessageFormat for complex strings
•Avoid concatenating translated strings
•Extract all user-facing text

Supporting Files

•templates/i18n-config.js: Configuration examples
•templates/locale-file.json: Translation file template