Extract new Flarum\Post namespace

src/Post/MergeableInterface.php

@@ -0,0 +1,33 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Post;
+
+/**
+ * A post that has the ability to be merged into an adjacent post.
+ *
+ * This is only implemented by certain types of posts. For example,
+ * if a "discussion renamed" post is posted immediately after another
+ * "discussion renamed" post, then the new one will be merged into the old one.
+ */
+interface MergeableInterface
+{
+    /**
+     * Save the model, given that it is going to appear immediately after the
+     * passed model.
+     *
+     * @param \Flarum\Post\Post|null $previous
+     * @return Post The model resulting after the merge. If the merge is
+     *     unsuccessful, this should be the current model instance. Otherwise,
+     *     it should be the model that was merged into.
+     */
+    public function saveAfter(Post $previous = null);
+}