1 files changed, 52 insertions, 0 deletions
diff --git a/MLEB/Translate/messagegroups/loaders/MessageGroupLoader.php b/MLEB/Translate/messagegroups/loaders/MessageGroupLoader.php
new file mode 100644
index 00000000..0a973a0f
--- /dev/null
+++ b/MLEB/Translate/messagegroups/loaders/MessageGroupLoader.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * This file contains an abstract class to be extended by group stores / loaders.
+ *
+ * @file
+ * @author Abijeet Patro
+ * @license GPL-2.0-or-later
+ */
+
+ /**
+  * An abstract class to be implemented by group loaders / stores
+  * @since 2019.05
+  */
+abstract class MessageGroupLoader {
+	/**
+	 * Fetches and returns an array of MessageGroups.
+	 * @return MessageGroup[] Array of message groups with group id as the key
+	 * @note Do not return an indexed based array as that would cause MessageGroups to
+	 * be ovewritten.
+	 */
+	abstract public function getGroups();
+
+	abstract public static function registerLoader( array &$groupLoader, array $deps );
+
+	/**
+	 * Safely merges first array to second array, throwing warning on duplicates and removing
+	 * duplicates from the first array.
+	 * @param array $additions Things to append
+	 * @param array &$to Where to append
+	 */
+	protected static function appendAutoloader( array $additions, array &$to ) {
+		foreach ( $additions as $class => $file ) {
+			if ( isset( $to[$class] ) && $to[$class] !== $file ) {
+				$msg = "Autoload conflict for $class: {$to[$class]} !== $file";
+				trigger_error( $msg, E_USER_WARNING );
+				continue;
+			}
+
+			$to[$class] = $file;
+		}
+	}
+
+	/**
+	 * Determines if dependencies have expired. Called if data in cache is stored
+	 * as a dependency wrapper.
+	 * @param DependencyWrapper $wrapper
+	 * @return bool true if expired, false otherwise.
+	 */
+	public function isExpired( DependencyWrapper $wrapper ) {
+		return $wrapper->isExpired();
+	}
+}