public function initElements()
    {
        $date = new \DateTime();
        $filename = 'metadata-' . $date->format('ymd');

        $nameElt = \tao_helpers_form_FormFactory::getElement('filename', 'Textbox');
        $nameElt->setDescription(__('File name'));
        $nameElt->setValue($filename);
        $nameElt->setUnit(".csv");
        $nameElt->addValidator(\tao_helpers_form_FormFactory::getValidator('NotEmpty'));
        $this->form->addElement($nameElt);

        $this->form->createGroup('options', __('Export metadata item'), array('xml_desc', 'filename', 'exportInstance'));
    }