X-Git-Url: http://source.bookstackapp.com/bookstack/blobdiff_plain/6bc72e157a346e708cee17d7c51560a0fdd084ff..refs/pull/806/head:/app/PageRevision.php

diff --git a/app/PageRevision.php b/app/PageRevision.php
index 1ffd63dbd..ffcc4f9d2 100644
--- a/app/PageRevision.php
+++ b/app/PageRevision.php
@@ -1,6 +1,5 @@
 <?php namespace BookStack;
 
-
 class PageRevision extends Model
 {
     protected $fillable = ['name', 'html', 'text', 'markdown', 'summary'];
@@ -25,11 +24,39 @@ class PageRevision extends Model
 
     /**
      * Get the url for this revision.
+     * @param null|string $path
      * @return string
      */
-    public function getUrl()
+    public function getUrl($path = null)
+    {
+        $url = $this->page->getUrl() . '/revisions/' . $this->id;
+        if ($path) {
+            return $url . '/' . trim($path, '/');
+        }
+        return $url;
+    }
+
+    /**
+     * Get the previous revision for the same page if existing
+     * @return \BookStack\PageRevision|null
+     */
+    public function getPrevious()
     {
-        return $this->page->getUrl() . '/revisions/' . $this->id;
+        if ($id = static::where('page_id', '=', $this->page_id)->where('id', '<', $this->id)->max('id')) {
+            return static::find($id);
+        }
+        return null;
     }
 
+    /**
+     * Allows checking of the exact class, Used to check entity type.
+     * Included here to align with entities in similar use cases.
+     * (Yup, Bit of an awkward hack)
+     * @param $type
+     * @return bool
+     */
+    public static function isA($type)
+    {
+        return $type === 'revision';
+    }
 }