diff --git a/inc/CalDAVRequest.php b/inc/CalDAVRequest.php
index cc66b87e..25bf693a 100644
--- a/inc/CalDAVRequest.php
+++ b/inc/CalDAVRequest.php
@@ -145,6 +145,16 @@ class CalDAVRequest
 
   }
 
+  /**
+  * Returns true if the URL referenced by this request points at a collection.
+  */
+  function IsCollection( ) {
+    if ( !isset($this->_is_collection) ) {
+      $this->_is_collection = preg_match( '#/$#', $this->path );
+    }
+    return $this->_is_collection;
+  }
+
   /**
   * Are we allowed to do the requested activity
   *