Merge pull request #48 from stelabouras/fix/current-locale

Refactor TXPreferredLocaleProvider logic

.github/workflows/swift.yml

@@ -9,10 +9,10 @@ on:
 jobs:
   build:
 
-    runs-on: macos-latest
+    runs-on: macos-12
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Build
       run: swift build -v
     - name: Run tests

CHANGELOG.md

@@ -68,3 +68,11 @@ key if the entry is not found.
 
 - Adds method to activate SDK from a Swift Package.
 - Adds reference to SwiftUI limitation in README.
+
+## Transifex iOS SDK 1.0.3
+
+*December 27, 2022*
+
+- Fixes TXPreferredLocaleProvider so that it uses the correct language candidate
+based on user's preference and supported languages by the app developer.
+- Fixes deprecation warnings on Github action.

Sources/Transifex/Core.swift

@@ -334,7 +334,7 @@ render '\(stringToRender)' locale code: \(localeCode) params: \(params). Error:
 /// A static class that is the main point of entry for all the functionality of Transifex Native throughout the SDK.
 public final class TXNative : NSObject {
     /// The SDK version
-    internal static let version = "1.0.2"
+    internal static let version = "1.0.3"
 
     /// The filename of the file that holds the translated strings and it's bundled inside the app.
     public static let STRINGS_FILENAME = "txstrings.json"

Sources/Transifex/Locales.swift

@@ -17,15 +17,23 @@ public protocol TXCurrentLocaleProvider {
     func currentLocale() -> String
 }
 
-/// Class that returns the language code of the current user's locale and falls back to "en" if the language
-/// code cannot be found.
+/// Class that returns the active language code that can be used for localization, based on the current user's
+/// language preferences and the locales that the application supports. The class falls back to "en" if the
+/// language code cannot be found.
 public final class TXPreferredLocaleProvider : NSObject {
+    private static let FALLBACK_LOCALE = "en"
+    private var _appLocales : [String]
     private var _currentLocale : String
 
-    override init() {
+    /// Designated initializer.
+    ///
+    /// - Parameter appLocales: The locales the the application supports.
+    init(_ appLocales: [String]) {
+        _appLocales = appLocales
+
         // Fetch the current locale on initialization and return it when it's
         // requested by the `currentLocale()` method.
-        _currentLocale = TXPreferredLocaleProvider.getCurrentLocale()
+        _currentLocale = Self.getCurrentLocale(_appLocales)
 
         super.init()
 
@@ -38,18 +46,33 @@ public final class TXPreferredLocaleProvider : NSObject {
 
     @objc
     private func currentLocaleDidChange() {
-        _currentLocale = TXPreferredLocaleProvider.getCurrentLocale()
+        _currentLocale = Self.getCurrentLocale(_appLocales)
     }
 
     private static func getPreferredLocale() -> Locale {
-        guard let preferredIdentifier = Locale.preferredLanguages.first else {
+        if let preferredLanguage = Locale.preferredLanguages.first {
+            return Locale(identifier: preferredLanguage)
+        }
+        else {
             return Locale.autoupdatingCurrent
         }
-        return Locale(identifier: preferredIdentifier)
     }
 
-    private static func getCurrentLocale() -> String {
-        return getPreferredLocale().languageCode ?? "en"
+    private static func getCurrentLocale(_ appLocales: [String]) -> String {
+        // Attempt to get the most preferred locale based on:
+        // * the supported app locales provided by the developer when
+        //   initializing the TXNative instance.
+        // * the preferred languages set by the user in the device Settings.
+        if let preferredLocalization = Bundle.preferredLocalizations(from: appLocales,
+                                                                     forPreferences: Locale.preferredLanguages).first {
+            return preferredLocalization
+        }
+        // Although it's highly unlikely that a preferred localization will not
+        // be extracted using the preferredLocalizations() call, we have a
+        // number of fallbacks in place to locate the best candidate.
+        else {
+            return getPreferredLocale().languageCode ?? FALLBACK_LOCALE
+        }
     }
 }
 
@@ -113,13 +136,19 @@ public final class TXLocaleState : NSObject {
         // Make sure we filter all duplicate values
         // by converting the array to a Set.
         var distinctAppLocales = Set(appLocales)
-        // Insert the source locale in case it hasn't been added.
-        distinctAppLocales.insert(sourceLocale)
-        self.appLocales = Array(distinctAppLocales)
+        // Remove the source locale (if it has been already added by the
+        // developer).
+        distinctAppLocales.remove(sourceLocale)
 
-        self.translatedLocales = self.appLocales.filter { $0 != sourceLocale }
+        self.translatedLocales = Array(distinctAppLocales)
+
+        self.appLocales = Array(distinctAppLocales)
+        // Add the source locale as the first element of the array, as the
+        // `TXPreferredLocaleProvider` (and `Bundle.preferredLocalizations` more
+        // specifically) uses the first element as a fallback.
+        self.appLocales.insert(sourceLocale, at: 0)
 
-        self.currentLocaleProvider = currentLocaleProvider ?? TXPreferredLocaleProvider()
+        self.currentLocaleProvider = currentLocaleProvider ?? TXPreferredLocaleProvider(self.appLocales)
     }
 
     /// Returns true if the given locale is the source locale, false otherwise.

Tests/TransifexTests/TransifexTests.swift

@@ -572,22 +572,47 @@ final class TransifexTests: XCTestCase {
         XCTAssertEqual(result, "ERROR")
     }
 
-    func testCurrentLocale() {
+    func testCurrentLocaleNotFirstPreference() {
         let appleLanguagesKey = "AppleLanguages"
         let storedLanguages = UserDefaults.standard.value(forKey: appleLanguagesKey)
 
-        UserDefaults.standard.set([ "el" ],
+        UserDefaults.standard.set([ "nl", "fr" ],
                                   forKey: appleLanguagesKey)
 
-        let locale = TXLocaleState(appLocales: [])
+        let locale = TXLocaleState(sourceLocale: "en",
+                                   appLocales: [ "fr", "de", "es", "it"])
 
         XCTAssertEqual(locale.currentLocale,
-                       "el")
+                       "fr")
 
         UserDefaults.standard.set(storedLanguages,
                                   forKey: appleLanguagesKey)
     }
 
+    func testCurrentLocaleNotAnyPreference() {
+        let appleLanguagesKey = "AppleLanguages"
+        let storedLanguages = UserDefaults.standard.value(forKey: appleLanguagesKey)
+
+        UserDefaults.standard.set([ "nl", "fr" ],
+                                  forKey: appleLanguagesKey)
+
+        let locale = TXLocaleState(sourceLocale: "en",
+                                   appLocales: [ "de", "es", "it"])
+
+        XCTAssertEqual(locale.currentLocale,
+                       "en")
+
+        UserDefaults.standard.set(storedLanguages,
+                                  forKey: appleLanguagesKey)
+    }
+
+    func testSourceLocalePosition() {
+        let locale = TXLocaleState(sourceLocale: "en",
+                                   appLocales: [ "fr", "el" ])
+
+        XCTAssertTrue(locale.appLocales.first == "en")
+    }
+
     func testTranslateWithSourceStringsInCache() {
         let sourceLocale = "en"
         let localeState = TXLocaleState(sourceLocale: sourceLocale,
@@ -661,7 +686,9 @@ final class TransifexTests: XCTestCase {
         ("testPlatformStrategyWithInvalidSourceString", testPlatformStrategyWithInvalidSourceString),
         ("testErrorPolicy", testErrorPolicy),
         ("testErrorPolicyException", testErrorPolicyException),
-        ("testCurrentLocale", testCurrentLocale),
+        ("testCurrentLocaleNotFirstPreference", testCurrentLocaleNotFirstPreference),
+        ("testCurrentLocaleNotAnyPreference", testCurrentLocaleNotAnyPreference),
+        ("testSourceLocalePosition", testSourceLocalePosition),
         ("testTranslateWithSourceStringsInCache", testTranslateWithSourceStringsInCache),
     ]
 }