'boolean(1)', 'UseThemeCSS' => 'boolean(1)', ); public function updateCMSFields(FieldList $fields) { $fields->addFieldsToTab('Root.FontAwesome', array( OptionsetField::create('UseThemeCSS', 'Theme dir font-awesome.css?') ->setDescription('You may want to use font-awesome.css from your theme directory') ->setSource(array( true => 'Yes', false => 'No' )), OptionsetField::create('UseCDN', 'CDN for loading frontend assets?') ->setDescription('Depending on hosting, your viewers may or may not get better performance using a CDN') ->setSource(array( true => 'Yes', false => 'No' )) )); } }