src/Forms/GridFieldRefreshButton.php
public function handleAction(GridField $gridField, $actionName, $arguments, $data)
    {
        if ($actionName == 'refresh') {
            return $this->handleRefresh($gridField);
        }
    }
public function handleAction(GridField $gridField, $actionName, $arguments, $data)
    {
        if ($actionName == 'refresh') {
            return $this->handleRefresh($gridField);
        }
    }
public function handleAction ( GridField $ gridField , $ actionName , $ arguments , $ data ) { if ( $ actionName == 'refresh' ) { return $ this -> handleRefresh ( $ gridField ) ; } }
Handle the refresh action.

@param GridField $gridField
@param string $actionName
@param array $arguments
@param array $data

@return null
Handle the refresh action .