Feat fallback locale

src/Locale/Locale.php

@@ -25,6 +25,14 @@ class Locale
      */
     public $default;
 
+    /**
+     * Fallback locale. Used when specific or default locale is missing translation.
+     * Should always be set to locale that includes all translations.
+     *
+     * @var string
+     */
+    public $fallback;
+
     /**
      * Set New Locale from an array
      *
@@ -44,7 +52,7 @@ public static function setLanguageFromArray(string $name, array $translations):
      */
     public static function setLanguageFromJSON(string $name, string $path): void
     {
-        if (! file_exists($path)) {
+        if (! file_exists($path) && self::$exceptions) {
             throw new Exception('Translation file not found.');
         }
 
@@ -55,13 +63,31 @@ public static function setLanguageFromJSON(string $name, string $path): void
 
     public function __construct(string $default)
     {
-        if (! \array_key_exists($default, self::$language)) {
+        if (! \array_key_exists($default, self::$language) && self::$exceptions) {
             throw new Exception('Locale not found');
         }
 
         $this->default = $default;
     }
 
+    /**
+     * Change fallback Locale
+     *
+     * @param $name
+     *
+     * @throws Exception
+     */
+    public function setFallback(string $name): self
+    {
+        if (! \array_key_exists($name, self::$language) && self::$exceptions) {
+            throw new Exception('Locale not found');
+        }
+
+        $this->fallback = $name;
+
+        return $this;
+    }
+
     /**
      * Change Default Locale
      *
@@ -71,7 +97,7 @@ public function __construct(string $default)
      */
     public function setDefault(string $name): self
     {
-        if (! \array_key_exists($name, self::$language)) {
+        if (! \array_key_exists($name, self::$language) && self::$exceptions) {
             throw new Exception('Locale not found');
         }
 
@@ -91,7 +117,7 @@ public function setDefault(string $name): self
      */
     public function getText(string $key, array $placeholders = [])
     {
-        $default = '{{'.$key.'}}';
+        $default = (self::$language[$this->fallback ?? ''] ?? [])[$key] ?? '{{'.$key.'}}';
 
         if (! \array_key_exists($key, self::$language[$this->default])) {
             if (self::$exceptions) {

tests/Locale/LocaleTest.php

@@ -77,4 +77,17 @@ public function testTexts(): void
 
         $this->fail('No exception was thrown');
     }
+
+    public function testFallback(): void
+    {
+        $locale = new Locale('he-IL');
+
+        $this->assertEquals('שלום', $locale->getText('hello'));
+        $this->assertEquals('{{world}}', $locale->getText('world'));
+
+        $locale->setFallback('en-US');
+
+        $this->assertEquals('שלום', $locale->getText('hello'));
+        $this->assertEquals('World', $locale->getText('world'));
+    }
 }