iOS Localization & Assets Standards

Priority: P1

Implementation Guidelines

Localization (L10n)

• String Catalogs (.stringcatalog): Use for primary localization in Xcode 15+. It provides a visual editor and compile-time checks for missing translations.
• Native Implementation: Use String(localized: "key") or LocalizedStringResource. Avoid manual NSLocalizedString where possible.
• Pluralization: Use String Catalogs' built-in pluralization support instead of complex code logic.
• Formatting: Use Formatted API for dates, numbers, and currencies to respect the user's locale.

Asset Management

• Asset Catalogs (.xcassets): Keep assets organized. Use folders with "Provides Namespace" enabled for large projects.
• SF Symbols: Use for standard icons to ensure consistency and accessibility.
• Vector Assets: Use PDF or SVG and enable "Preserve Vector Data" for resolution independence.

Best Practices

• Hardcoded Strings: Never use hardcoded strings in UI. Every user-facing string must be localized.
• Base Bundle: Ensure Base localization is complete before adding other languages.

Anti-Patterns

• Manual String Formatting: **No manual currency symbol concat**: Use NumberFormatter or .formatted(.currency).
• Loose Asset Files: **No loose png/jpg files in repo**: Always use Asset Catalogs.
• Untranslated Keys: **No placeholder strings**: Ensure 100% coverage in String Catalogs.

References

• L10n & Asset Organization