protected function renderFilterCellContent()
    {
        if (is_string($this->filter)) {
            echo $this->filter;
        } else {
            if ($this->filter !== false && $this->grid->filter !== null && $this->name !== null && strpos(
                    $this->name,
                    '.'
                ) === false
            ) {
                if ($this->filterInputOptions) {
                    $filterInputOptions = $this->filterInputOptions;
                    if (empty($filterInputOptions['id'])) {
                        $filterInputOptions['id'] = false;
                    }
                } else {
                    $filterInputOptions = array();
                }
                if (is_array($this->filter)) {
                    $filterInputOptions['prompt'] = '';
                    echo TbHtml::activeDropDownList(
                        $this->grid->filter,
                        $this->name,
                        $this->filter,
                        $filterInputOptions
                    );
                } else {
                    if ($this->filter === null) {
                        echo TbHtml::activeTextField($this->grid->filter, $this->name, $filterInputOptions);
                    }
                }
            } else {
                parent::renderFilterCellContent();
            }
        }
    }