create directoryIsEmpty() in LfmHelper

Author: streamtw

src/controllers/DeleteController.php

@@ -29,7 +29,7 @@ public function getDelete()
         }
 
         if (File::isDirectory($file_to_delete)) {
-            if (sizeof(File::files($file_to_delete)) != 0) {
+            if (!parent::directoryIsEmpty($file_to_delete)) {
                 return $this->error('delete-folder');
             }
 

src/traits/LfmHelpers.php

@@ -174,6 +174,11 @@ public function createFolderByPath($path)
         }
     }
 
+    public function directoryIsEmpty($directory_path)
+    {
+        return count(File::allFiles($directory_path)) == 0;
+    }
+
 
     /****************************
      ***    Miscellaneouses   ***