App Localization

Manage iOS/macOS .strings files in Tuist-based projects.

Project Structure

<ModuleName>/
├── Resources/
│   ├── en.lproj/Localizable.strings       # Primary language (English)
│   ├── <locale>.lproj/Localizable.strings # Additional locales
│   └── ...
├── Derived/
│   └── Sources/
│       └── TuistStrings+<ModuleName>.swift  # Generated by Tuist
└── Sources/
    └── **/*.swift  # Uses <ModuleName>Strings.Section.key

After editing .strings files, run

tuist generate

to regenerate type-safe accessors.

Complete Localization Workflow

Step 1: Identify Hardcoded Strings

Find hardcoded strings in Swift files:

bash

# Find Text("...") patterns with hardcoded strings
grep -rn 'Text("[A-Z]' <ModuleName>/Sources/
grep -rn 'title: "[A-Z]' <ModuleName>/Sources/
grep -rn 'label: "[A-Z]' <ModuleName>/Sources/
grep -rn 'placeholder: "[A-Z]' <ModuleName>/Sources/

Step 2: Add Translation Keys

Add keys to all language files:

en.lproj/Localizable.strings (primary):

/* Section description */
"section.key.name" = "English value";
"section.key.withParam" = "Value with %@";

Other locales (translate appropriately):

"section.key.name" = "<translated value>";
"section.key.withParam" = "<translated> %@";

Step 3: Generate Type-Safe Accessors

bash

tuist generate

This creates

Derived/Sources/TuistStrings+<ModuleName>.swift

with accessors:

```
<ModuleName>Strings.Section.keyName
```
(static property)

<ModuleName>Strings.Section.keyWithParam(value)

(static function for %@ params)

See references/tuist-strings-patterns.md for detailed patterns.

Step 4: Update Swift Code

Replace hardcoded strings with generated accessors.

Pattern Mapping

Hardcoded Pattern	Localized Pattern
`Text("Title")`	`Text(<Module>Strings.Section.title)`
`Text("Hello, \(name)")`	`Text(<Module>Strings.Section.hello(name))`
`title: "Submit"`	`title: <Module>Strings.Action.submit`
`placeholder: "Enter..."`	`placeholder: <Module>Strings.Field.placeholder`

Example Transformations

Before:

swift

Text("Settings")
    .font(.headline)

TextField("Enter your name", text: $name)

Button("Submit") { ... }

Text("Hello, \(userName)!")

After:

swift

Text(<Module>Strings.Section.settings)
    .font(.headline)

TextField(<Module>Strings.Field.namePlaceholder, text: $name)

Button(<Module>Strings.Action.submit) { ... }

Text(<Module>Strings.Greeting.hello(userName))

Handling Parameters and Plurals

String with parameter (key:

"search.noResults" = "No results for \"%@\""

swift

// Before
Text("No results for \"\(searchText)\"")

// After
Text(<Module>Strings.Search.noResults(searchText))

Conditional plurals:

swift

// Keys:
// "item.count" = "%d item"
// "item.countPlural" = "%d items"

// Swift:
let label = count == 1
    ? <Module>Strings.Item.count(count)
    : <Module>Strings.Item.countPlural(count)

Multiple parameters (key:

"message.detail" = "%@ uploaded %d files"

swift

Text(<Module>Strings.Message.detail(userName, fileCount))

Step 5: Validate Changes

Build the project to catch missing keys
Run validation script to check consistency:

bash

python scripts/validate_strings.py /path/to/<ModuleName>

AI-Powered Translation

When translating strings to non-English locales:

Read the English source string
Consider context from the key name (e.g.,
```
search.noResults
```
= search UI)
Translate appropriately for the target locale:
- zh-Hans: Simplified Chinese, formal but friendly
- zh-Hant: Traditional Chinese
- ja: Japanese, polite form (desu/masu style)
- ko: Korean, polite form (hamnida/yo style)
- de/fr/es/etc.: Appropriate regional conventions
Preserve all placeholders exactly (%@, %d, %ld, etc.)

Translation context by UI element:

Labels: Keep concise
Buttons: Action-oriented verbs
Placeholders: Instructive tone
Error messages: Helpful and clear
Confirmations: Clear consequences

Validation Scripts

Validate .strings Files

bash

python scripts/validate_strings.py /path/to/<ModuleName>

Checks for:

Missing keys between languages
Duplicate keys
Placeholder mismatches (%@, %d, %ld)
Untranslated strings (value = English)

Sync Missing Translations

Report missing keys:

bash

python scripts/sync_translations.py /path/to/<ModuleName> --report

Add missing keys as placeholders:

bash

python scripts/sync_translations.py /path/to/<ModuleName> --sync

Key Naming Convention

Pattern:

"domain.context.element"

→

<Module>Strings.Domain.Context.element

Domain-Focused Naming (User Mental Model)

Keys should reflect what the user is doing, not technical UI components:

User Mental Model	Key Pattern	Generated Accessor
"I'm looking at my profile"	`"profile.name"`	`Strings.Profile.name`
"I'm testing a build"	`"betaBuild.whatToTest"`	`Strings.BetaBuild.whatToTest`
"I'm adding a tester"	`"testerGroup.addTester"`	`Strings.TesterGroup.addTester`
"Something went wrong with sync"	`"sync.error.failed"`	`Strings.Sync.Error.failed`

Good vs Bad Examples

Bad (Technical)	Good (Domain-Focused)
`button.save`	`profile.save`
`field.email`	`registration.email`
`placeholder.search`	`appSelector.searchPlaceholder`
`error.network`	`sync.connectionFailed`
`label.title`	`settings.title`
`alert.confirm`	`build.expireConfirm`

Structure by Feature/Screen

Organize keys by the feature or screen where they appear:

/* Profile Section */
"profile.title" = "Profile";
"profile.name" = "Name";
"profile.save" = "Save Changes";
"profile.saveSuccess" = "Profile updated";

/* Beta Builds */
"betaBuild.title" = "Beta Builds";
"betaBuild.whatToTest" = "What to Test";
"betaBuild.submitForReview" = "Submit for Review";
"betaBuild.expireConfirm" = "Expire this build?";

/* Tester Groups */
"testerGroup.create" = "Create Group";
"testerGroup.addTester" = "Add Tester";
"testerGroup.empty" = "No testers yet";

This mirrors how users think: "I'm in Beta Builds, submitting for review" →

betaBuild.submitForReview

.strings File Format

/* Comment describing the section */
"key.name" = "Value";
"key.with.parameter" = "Hello, %@!";
"key.with.number" = "%d items";
"key.with.multiple" = "%1$@ has %2$d items";

Rules:

Keys must be unique within a file
Values are UTF-8 encoded
Escape quotes with backslash:
```
\"
```
Line ends with semicolon
Use positional parameters (%1$@, %2$d) when order differs between languages

app-localization

NPX Install

Tags

SKILL.md Content

App Localization

Project Structure

Complete Localization Workflow

Step 1: Identify Hardcoded Strings

Step 2: Add Translation Keys

Step 3: Generate Type-Safe Accessors

Step 4: Update Swift Code

Pattern Mapping

Example Transformations

Handling Parameters and Plurals

Step 5: Validate Changes

AI-Powered Translation

Validation Scripts

Validate .strings Files

Sync Missing Translations

Key Naming Convention

Domain-Focused Naming (User Mental Model)

Good vs Bad Examples

Structure by Feature/Screen

.strings File Format