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lib/pkp/classes/i18n/translation/LocaleFile.php

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+<?php
+
+declare(strict_types=1);
+
+/**
+ * @defgroup i18n I18N
+ * Implements localization concerns such as locale files, time zones, and country lists.
+ */
+
+/**
+ * @file classes/i18n/translation/LocaleFile.php
+ *
+ * Copyright (c) 2014-2021 Simon Fraser University
+ * Copyright (c) 2000-2021 John Willinsky
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class LocaleFile
+ *
+ * @ingroup i18n
+ *
+ * @brief Loads translations from a locale file
+ */
+
+namespace PKP\i18n\translation;
+
+use DateInterval;
+use Exception;
+use Gettext\Generator\ArrayGenerator;
+use Gettext\Loader\LoaderInterface;
+use Gettext\Loader\MoLoader;
+use Gettext\Loader\PoLoader;
+use Gettext\Translations;
+use Illuminate\Support\Facades\Cache;
+use SplFileInfo;
+
+abstract class LocaleFile
+{
+    /** @var string Max lifetime for the cache, a new cache file is created whenever the translation file is modified */
+    protected const MAX_CACHE_LIFETIME = '1 year';
+
+    /**
+     * Retrieves a suitable loader
+     */
+    public static function getLoader(string $path): LoaderInterface
+    {
+        return match (strtolower((new SplFileInfo($path))->getExtension())) {
+            'po' => new PoLoader(),
+            'mo' => new MoLoader(),
+            default => throw new Exception("There's no suitable gettext loader for this file type")
+        };
+    }
+
+    /**
+     * Loads the translations from a file
+    */
+    public static function loadTranslations(string $path): Translations
+    {
+        return self::getLoader($path)->loadFile($path);
+    }
+
+    /**
+     * Loads the translations from a file as an array and caches the content physically as a PHP file in order to use the opcache
+    */
+    public static function loadArray(string $path, bool $useCache = false): array
+    {
+        $loader = fn () => (new ArrayGenerator(['includeEmpty' => false]))->generateArray(static::loadTranslations($path));
+        $key = __METHOD__ . static::MAX_CACHE_LIFETIME . $path . filemtime($path);
+        return $useCache ? Cache::remember($key, DateInterval::createFromDateString(static::MAX_CACHE_LIFETIME), $loader) : $loader();
+    }
+}