mac-cain13 · Mar 11, 2021 · Mar 11, 2021 · Mar 11, 2021
Showing with 110 additions and 3 deletions.

+87 −3 Library/Core/StringResource.swift

+23 −0 Library/UIKit/ImageResource+UIKit.swift
diff --git a/Library/Core/StringResource.swift b/Library/Core/StringResource.swift
@@ -22,7 +22,10 @@ public protocol StringResourceType {
 
   /// Locales of the a localizable string
   var locales: [String] { get }
-
+
+  /// The value to return if key is nil or if a localized string for key can’t be found in the table.
+  var value: String? { get }
+
   /// Comment directly before and/or after the string, if any
   var comment: String? { get }
 }
@@ -40,15 +43,96 @@ public struct StringResource: StringResourceType {
 
   /// Locales of the a localizable string
   public let locales: [String]
-
+
+  /// The value to return if key is nil or if a localized string for key can’t be found in the table.
+  public let value: String?
+
   /// Comment directly before and/or after the string, if any
   public let comment: String?
 
-  public init(key: String, tableName: String, bundle: Bundle, locales: [String], comment: String?) {
+  public init(key: String, tableName: String, bundle: Bundle, locales: [String], value: String?, comment: String?) {
     self.key = key
     self.tableName = tableName
     self.bundle = bundle
     self.locales = locales
+    self.value = value
     self.comment = comment
   }
+
+  public func callAsFunction(preferredLanguages: [String]? = nil) -> String {
+    guard let preferredLanguages = preferredLanguages else {
+      return NSLocalizedString(key, bundle: bundle, value: value ?? "", comment: comment ?? "")
+    }
+
+    guard let (_, bundle) = localeBundle(tableName: tableName, preferredLanguages: preferredLanguages) else {
+      return value ?? ""
+    }
+
+    return NSLocalizedString(key, bundle: bundle, value: "", comment: comment ?? "")
+  }
+
+  private var applicationLocale: Locale {
+    bundle.preferredLocalizations.first.flatMap { Locale(identifier: $0) } ?? Locale.current
+  }
+
+  private func localeBundle(tableName: String, preferredLanguages: [String]) -> (Foundation.Locale, Foundation.Bundle)? {
+    // Filter preferredLanguages to localizations, use first locale
+    var languages = preferredLanguages
+      .map { Locale(identifier: $0) }
+      .prefix(1)
+      .flatMap { locale -> [String] in
+        if bundle.localizations.contains(locale.identifier) {
+          if let language = locale.languageCode, bundle.localizations.contains(language) {
+            return [locale.identifier, language]
+          } else {
+            return [locale.identifier]
+          }
+        } else if let language = locale.languageCode, bundle.localizations.contains(language) {
+          return [language]
+        } else {
+          return []
+        }
+      }
+
+    // If there's no languages, use development language as backstop
+    if languages.isEmpty {
+      if let developmentLocalization = bundle.developmentLocalization {
+        languages = [developmentLocalization]
+      }
+    } else {
+      // Insert Base as second item (between locale identifier and languageCode)
+      languages.insert("Base", at: 1)
+
+      // Add development language as backstop
+      if let developmentLocalization = bundle.developmentLocalization {
+        languages.append(developmentLocalization)
+      }
+    }
+
+    // Find first language for which table exists
+    // Note: key might not exist in chosen language (in that case, key will be shown)
+    for language in languages {
+      if let lproj = bundle.url(forResource: language, withExtension: "lproj"),
+         let lbundle = Bundle(url: lproj)
+      {
+        let strings = lbundle.url(forResource: tableName, withExtension: "strings")
+        let stringsdict = lbundle.url(forResource: tableName, withExtension: "stringsdict")
+
+        if strings != nil || stringsdict != nil {
+          return (Locale(identifier: language), lbundle)
+        }
+      }
+    }
+
+    // If table is available in main bundle, don't look for localized resources
+    let strings = bundle.url(forResource: tableName, withExtension: "strings", subdirectory: nil, localization: nil)
+    let stringsdict = bundle.url(forResource: tableName, withExtension: "stringsdict", subdirectory: nil, localization: nil)
+
+    if strings != nil || stringsdict != nil {
+      return (applicationLocale, bundle)
+    }
+
+    // If table is not found for requested languages, key will be shown
+    return nil
+  }
 }
diff --git a/Library/UIKit/ImageResource+UIKit.swift b/Library/UIKit/ImageResource+UIKit.swift
@@ -0,0 +1,23 @@
+//
+//  ImageResource+UIKit.swift
+//  R.swift.Library
+//
+//  Created by kemchenj on 03-11-21.
+//  From: https://github.com/mac-cain13/R.swift.Library
+//  License: MIT License
+//
+
+#if os(iOS) || os(tvOS)
+import UIKit
+
+extension ImageResource {
+  /// Returns the image from this resource (R.image.*) that is compatible with the trait collection.
+  ///
+  /// - Parameter traitCollection: The traits associated with the intended environment for the image. Use this parameter to ensure that the correct variant of the image is loaded. If you specify nil, this method uses the traits associated with the main screen.
+  /// - Returns: Traits that describe the desired image to retrieve, pass nil to use traits that describe the main screen.
+  public func callAsFunction(compatibleWith traitCollection: UITraitCollection? = nil) -> UIImage? {
+    UIImage(resource: self, compatibleWith: traitCollection)
+  }
+}
+#endif
+