Understanding XCStrings: The New Localization Format in Modern iOS Development

The introduction of .xcstrings format marks a significant improvement in how we handle localizations in iOS and macOS development. Let’s dive deep into what makes this new format special and why you should consider using it.

What is XCStrings?

XCStrings is Apple’s new localization format that replaces the traditional .strings and .stringsdict files. It’s a JSON-based format that combines the functionality of both previous formats into a single, more maintainable file.

Key Benefits

• Single File Management: Instead of managing multiple .strings files, all languages are contained in one .xcstrings file
• Built-in Plural Support: No need for separate .stringsdict files
• Better Version Control: JSON format makes it easier to track changes and resolve conflicts
• IDE Support: Rich editor support in Xcode with inline warnings and errors

Structure of an XCStrings File

{
  "sourceLanguage" : "en",
  "strings" : {
    "welcome_message" : {
      "localizations" : {
        "en" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Welcome to the app!"
          }
        },
        "it" : {
          "stringUnit" : {
            "state" : "translated",
            "value" : "Benvenuto nell'app!"
          }
        }
      }
    },
    "files_count" : {
      "extractionState" : "manual",
      "localizations" : {
        "en" : {
          "variations" : {
            "plural" : {
              "one" : {
                "stringUnit" : {
                  "state" : "translated",
                  "value" : "%d file"
                }
              },
              "other" : {
                "stringUnit" : {
                  "state" : "translated",
                  "value" : "%d files"
                }
              },
              "zero" : {
                "stringUnit" : {
                  "state" : "translated",
                  "value" : "No files"
                }
              }
            }
          }
        }
      }
    }
  },
  "version" : "1.0"
}

Migration from .strings to .xcstrings

Xcode provides built-in migration tools to convert your existing .strings and .stringsdict files to the new format:

1. Select your .strings file in Xcode
2. Choose Editor > Export Localizations
3. Choose Editor > Import Localizations with the new format

Managing XCStrings with LocalizApp

LocalizApp fully supports the new .xcstrings format, making it even easier to manage your localizations:

• View and edit all languages in one place
• Automatic plural forms management
• Easy migration from older formats
• Instant validation of your strings
• One-click translation with DeepL or Google Translate

Best Practices with XCStrings

1. Organization:

// Group related strings with prefixes
"login.title" = "Welcome";
"login.username" = "Username";
"login.password" = "Password";

2. Comments and Context:

/// Used in the main welcome screen
"welcome.title" = "Welcome";

3. Variable Handling:

// In code
String(localized: "welcome.user \(name)", 
       comment: "Greeting for user")

// In xcstrings
"welcome.user" : {
  "localizations" : {
    "en" : {
      "stringUnit" : {
        "state" : "translated",
        "value" : "Welcome, %@!"
      }
    }
  }
}

Debugging and Validation

XCStrings provides better error detection:

• Missing translations are clearly marked
• Format string mismatches are caught at compile time
• Invalid plural rules are highlighted

Conclusion

The .xcstrings format represents a significant step forward in iOS and macOS localization. It simplifies management, reduces errors, and provides better tools for developers. Combined with LocalizApp, it makes handling app localizations more efficient than ever.

Ready to modernize your app’s localization? Download LocalizApp from the Mac App Store and experience the power of modern localization management with full .xcstrings support.