Grid/Grid.php
public function getFilter($columnId)
    {
        if ($this->hash === null) {
            throw new \Exception(self::GET_FILTERS_NO_REQUEST_HANDLED_EX_MSG);
        }

        $sessionFilters = $this->getFilters();

        return isset($sessionFilters[$columnId]) ? $sessionFilters[$columnId] : null;
    }
public function getFilter($columnId)
    {
        if ($this->hash === null) {
            throw new \Exception(self::GET_FILTERS_NO_REQUEST_HANDLED_EX_MSG);
        }

        $sessionFilters = $this->getFilters();

        return isset($sessionFilters[$columnId]) ? $sessionFilters[$columnId] : null;
    }
Returns the filter of a column stored in session.

@param string $columnId
Id of the column

@throws \Exception

@return Filter