String catalog format

Xcode String Catalogs (.xcstrings) are JSON files that store localizable strings for Apple platforms.

File structure

json

{
  "sourceLanguage": "en",
  "strings": {
    "Hello, World!": {
      "localizations": {
        "en": {
          "stringUnit": {
            "state": "translated",
            "value": "Hello, World!"
          }
        },
        "de": {
          "stringUnit": {
            "state": "translated",
            "value": "Hallo, Welt!"
          }
        }
      }
    }
  },
  "version": "1.0"
}

Translation states

newString has not been translated yet
translatedString has been translated
needs_reviewTranslation needs review (e.g., source changed)

Pluralization

String Catalogs support CLDR plural categories for handling different grammatical number forms.

Plural categories

zero - For languages with zero form
one - Singular form
two - Dual form
few - Paucal form
many - Many form
other - General plural form (required)

Example

json

"%lld items": {
  "localizations": {
    "en": {
      "variations": {
        "plural": {
          "one": {
            "stringUnit": {
              "state": "translated",
              "value": "%lld item"
            }
          },
          "other": {
            "stringUnit": {
              "state": "translated",
              "value": "%lld items"
            }
          }
        }
      }
    }
  }
}

Variables

autoglot preserves all format specifiers and variable substitutions during translation.

Supported format specifiers

Specifier	Description
`%@`	Object (String, etc.)
`%d, %i`	Integer
`%lld`	Long integer
`%f`	Floating point
`%1$@, %2$@`	Positional arguments

String interpolation

Swift string interpolation syntax is also preserved:

yaml

"Hello, \(name)!" → "Hallo, \(name)!"
"You have \(count) messages" → "Sie haben \(count) Nachrichten"