symfony · mpdude · Feb 24, 2022 · Feb 28, 2022 · Feb 28, 2022 · Feb 28, 2022
diff --git a/src/Symfony/Bundle/FrameworkBundle/Command/TranslationDebugCommand.php b/src/Symfony/Bundle/FrameworkBundle/Command/TranslationDebugCommand.php
@@ -370,7 +370,7 @@ private function loadFallbackCatalogues(string $locale, array $transPaths): arra
     {
         $fallbackCatalogues = [];
         if ($this->translator instanceof Translator || $this->translator instanceof DataCollectorTranslator || $this->translator instanceof LoggingTranslator) {
-            foreach ($this->translator->getFallbackLocales() as $fallbackLocale) {
+            foreach ($this->translator->getFallbackLocaleProvider()->getUltimateFallbackLocales() as $fallbackLocale) {
                 if ($fallbackLocale === $locale) {
                     continue;
                 }

diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -1269,7 +1269,14 @@ private function registerTranslatorConfiguration(array $config, ContainerBuilder
         $container->setAlias('translator', 'translator.default')->setPublic(true);
         $container->setAlias('translator.formatter', new Alias($config['formatter'], false));
         $translator = $container->findDefinition('translator.default');
-        $translator->addMethodCall('setFallbackLocales', [$config['fallbacks'] ?: [$defaultLocale]]);
+
+        if ($container->has('translation.fallback_locale_provider')) {
+            $container
+                ->findDefinition('translation.fallback_locale_provider')
+                ->replaceArgument(0, [$config['fallbacks'] ?: [$defaultLocale]]);
+        } else {
+            $translator->addMethodCall('setFallbackLocales', [$config['fallbacks'] ?: [$defaultLocale]]);
+        }
 
         $defaultOptions = $translator->getArgument(4);
         $defaultOptions['cache_dir'] = $config['cache_dir'];

diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/translation.php b/src/Symfony/Bundle/FrameworkBundle/Resources/config/translation.php
@@ -27,6 +27,8 @@
 use Symfony\Component\Translation\Extractor\ChainExtractor;
 use Symfony\Component\Translation\Extractor\ExtractorInterface;
 use Symfony\Component\Translation\Extractor\PhpExtractor;
+use Symfony\Component\Translation\FallbackLocaleProvider;
+use Symfony\Component\Translation\FallbackLocaleProviderInterface;
 use Symfony\Component\Translation\Formatter\MessageFormatter;
 use Symfony\Component\Translation\Loader\CsvFileLoader;
 use Symfony\Component\Translation\Loader\IcuDatFileLoader;
@@ -59,6 +61,7 @@
                     'debug' => param('kernel.debug'),
                 ],
                 abstract_arg('enabled locales'),
+                service('translation.fallback_locale_provider')->ignoreOnInvalid(),
             ])
             ->call('setConfigCacheFactory', [service('config_cache_factory')])
             ->tag('kernel.locale_aware')
@@ -163,4 +166,10 @@
             ->tag('container.service_subscriber', ['id' => 'translator'])
             ->tag('kernel.cache_warmer')
     ;
+
+    if (class_exists(FallbackLocaleProvider::class)) {
+        $container->services()
+            ->set('translation.fallback_locale_provider', FallbackLocaleProvider::class)
+            ->alias(FallbackLocaleProviderInterface::class, 'translation.fallback_locale_provider');
+    }
 };
@@ -6,6 +6,7 @@ CHANGELOG
 
  * Parameters implementing `TranslatableInterface` are processed
  * Add the file extension to the `XliffFileDumper` constructor
+ * Add `FallbackLocaleProvider` to configure the fallback locale chain in `Translator`
 
 5.4
 ---

@@ -51,7 +51,7 @@ public function lateCollect()
     public function collect(Request $request, Response $response, \Throwable $exception = null)
     {
         $this->data['locale'] = $this->translator->getLocale();
-        $this->data['fallback_locales'] = $this->translator->getFallbackLocales();
+        $this->data['fallback_locales'] = $this->translator->getFallbackLocaleProvider()->getUltimateFallbackLocales();
     }
 
     /**

@@ -102,6 +102,8 @@ public function warmUp(string $cacheDir): array
      */
     public function getFallbackLocales(): array
     {
+        trigger_deprecation('symfony/translation', '6.2', 'DataCollectorTranslator::getFallbackLocales() is deprecated. Get the FallbackLocaleProvider instead.');
-        trigger_deprecation('symfony/translation', '6.2', 'DataCollectorTranslator::getFallbackLocales() is deprecated. Get the FallbackLocaleProvider instead.');
+        trigger_deprecation('symfony/translation', '6.2', '"%s::getFallbackLocales()" is deprecated, use "%s::getUltimateFallbackLocales()" instead.', DataCollectorTranslator::class, FallbackLocaleProvider::class);
-        trigger_deprecation('symfony/translation', '6.2', 'DataCollectorTranslator::getFallbackLocales() is deprecated. Get the FallbackLocaleProvider instead.');
+        trigger_deprecation('symfony/translation', '6.2', '"%s::getFallbackLocales()" is deprecated, use "%s::getUltimateFallbackLocales()" instead.', DataCollectorTranslator::class, FallbackLocaleProvider::class);
+
         if ($this->translator instanceof Translator || method_exists($this->translator, 'getFallbackLocales')) {
             return $this->translator->getFallbackLocales();
         }

@@ -0,0 +1,100 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Translation;
+
+use Symfony\Component\Translation\Exception\InvalidArgumentException;
+
+/**
+ * Derives fallback locales based on ICU parent locale information, by shortening locale
+ * sub tags and ultimately by going through a list of configured fallback locales.
+ *
+ * @author Matthias Pigulla <mp@webfactory.de>
+ */
+class FallbackLocaleProvider implements FallbackLocaleProviderInterface
+{
+    /**
+     * @var string[]
+     *
+     * List of fallback locales to add _after_ the ones derived from ICU information.
+     */
+    private array $ultimateFallbackLocales;
+
+    private ?array $parentLocales = null;
+
+    /**
+     * @param string[] $ultimateFallbackLocales
+     *
+     * @throws InvalidArgumentException If a locale contains invalid characters
+     */
+    public function __construct(array $ultimateFallbackLocales = [])
+    {
+        foreach ($ultimateFallbackLocales as $locale) {
+            LocaleValidator::validate($locale);
+        }
+
+        $this->ultimateFallbackLocales = $ultimateFallbackLocales;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getUltimateFallbackLocales(): array
+    {
+        return $this->ultimateFallbackLocales;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function computeFallbackLocales(string $locale): array
+    {
+        LocaleValidator::validate($locale);
+
+        $this->parentLocales ??= json_decode(file_get_contents(__DIR__.'/Resources/data/parents.json'), true);
+
+        $originLocale = $locale;
+        $locales = [];
+
+        while ($locale) {
+            $parent = $this->parentLocales[$locale] ?? null;
+
+            if ($parent) {
+                $locale = 'root' !== $parent ? $parent : null;
+            } elseif (\function_exists('locale_parse')) {
+                $localeSubTags = locale_parse($locale);
+                $locale = null;
+                if (1 < \count($localeSubTags)) {
+                    array_pop($localeSubTags);
+                    $locale = locale_compose($localeSubTags) ?: null;
+                }
+            } elseif ($i = strrpos($locale, '_') ?: strrpos($locale, '-')) {
+                $locale = substr($locale, 0, $i);
+            } else {
+                $locale = null;
+            }
+
+            if (null !== $locale) {
+                $locales[] = $locale;
+            }
+        }
+
+        foreach ($this->ultimateFallbackLocales as $fallback) {
+            if ($fallback === $originLocale) {
+                continue;
+            }
+
+            $locales[] = $fallback;
+        }
+
+        return array_unique($locales);
+    }
+}
@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Translation;
+
+use Symfony\Component\Translation\Exception\InvalidArgumentException;
+
+/**
+ * For a given locale, implementations provide the list of alternative locales to
+ * try when a translation cannot be found.
+ *
+ * @author Matthias Pigulla <mp@webfactory.de>
+ */
+interface FallbackLocaleProviderInterface
+{
+    /**
+     * @internal
+     *
+     * @return string[]
+     */
+    public function getUltimateFallbackLocales(): array;
+
+    /**
+     * For a given locale, this method provides the ordered list of alternative (fallback) locales
+     * to try.
+     *
+     * @return string[]
+     */
+    public function computeFallbackLocales(string $locale): array;
+}
@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Translation;
+
+use Symfony\Component\Translation\Exception\InvalidArgumentException;
+
+/**
+ * Asserts (syntactical) validity for given locale identifiers.
+ *
+ * @author Matthias Pigulla <mp@webfactory.de>
+ */
+class LocaleValidator
+{
+    /**
+     * Asserts that the locale is valid, throws an Exception if not.
+     *
+     * @throws InvalidArgumentException If the locale contains invalid characters
+     */
+    public static function validate(string $locale): void
+    {
+        if (!preg_match('/^[a-z0-9@_\\.\\-]*$/i', $locale)) {
+            throw new InvalidArgumentException(sprintf('Invalid "%s" locale.', $locale));
+        }
+    }
+}
@@ -91,6 +91,8 @@ public function getCatalogues(): array
      */
     public function getFallbackLocales(): array
     {
+        trigger_deprecation('symfony/translation', '6.2', 'LoggingTranslator::getFallbackLocales() is deprecated. Get the FallbackLocaleProvider instead.');
+
         if ($this->translator instanceof Translator || method_exists($this->translator, 'getFallbackLocales')) {
             return $this->translator->getFallbackLocales();
         }
-Original file line number
+Diff line change
@@ Expand Up / @@ -6,6 +6,7 @@ CHANGELOG @@
      * Parameters implementing `TranslatableInterface` are processed
      * Add the file extension to the `XliffFileDumper` constructor
+     * Add `FallbackLocaleProvider` to configure the fallback locale chain in `Translator`
 .4
     ---
@@ Expand Down @@