Move languageExists() to the factory

lib/private/l10n.php

@@ -462,16 +462,10 @@ class OC_L10N implements \OCP\IL10N {
 	 * @param string $app
 	 * @param string $lang
 	 * @return bool
+	 * @deprecated 9.0.0 Use \OC::$server->getL10NFactory()->languageExists() instead
 	 */
 	public static function languageExists($app, $lang) {
-		if ($lang === 'en') {//english is always available
-			return true;
-		}
-		$dir = self::findI18nDir($app);
-		if(is_dir($dir)) {
-			return file_exists($dir.'/'.$lang.'.json');
-		}
-		return false;
+		return \OC::$server->getL10NFactory()->languageExists($app, $lang);
 	}
 
 	/**

lib/private/l10n/factory.php

@@ -37,6 +37,9 @@ class Factory implements IFactory {
 	 */
 	protected $instances = [];
 
+	/**
+	 * @var array Structure: App => string[]
+	 */
 	protected $availableLanguages = [];
 
 	/**
@@ -93,6 +96,20 @@ class Factory implements IFactory {
 		return $available;
 	}
 
+	/**
+	 * @param string|null $app App id or null for core
+	 * @param string $lang
+	 * @return bool
+	 */
+	public function languageExists($app, $lang) {
+		if ($lang === 'en') {//english is always available
+			return true;
+		}
+
+		$languages = $this->findAvailableLanguages($app);
+		return array_search($lang, $languages);
+	}
+
 	/**
 	 * find the l10n directory
 	 *

lib/public/l10n/ifactory.php

@@ -42,4 +42,12 @@ interface IFactory {
 	 * @since 9.0.0
 	 */
 	public function findAvailableLanguages($app = null);
+
+	/**
+	 * @param string|null $app App id or null for core
+	 * @param string $lang
+	 * @return bool
+	 * @since 9.0.0
+	 */
+	public function languageExists($app, $lang);
 }