body

@@ -28,6 +28,9 @@ class DataArray {
     {
         $name = strtolower($name);
         if($append && is_string($val) && $this->get($name)!==null ){
+            if(!isset($this->attribute[$name])){
+                $this->attribute[$name] = '';
+            }
             $this->attribute[$name] .= $val;
         }else{
             $this->attribute[$name] = $val;