src/Filter/Setting/Simple.php
protected function getFrontendFilterValue($arrWidget, $arrFilterUrl, $strKeyOption)
    {
        // Toggle if active.
        if ($this->isActiveFrontendFilterValue($arrWidget, $arrFilterUrl, $strKeyOption)) {
            return '';
        }
        return $strKeyOption;
    }
protected function getFrontendFilterValue($arrWidget, $arrFilterUrl, $strKeyOption)
    {
        // Toggle if active.
        if ($this->isActiveFrontendFilterValue($arrWidget, $arrFilterUrl, $strKeyOption)) {
            return '';
        }
        return $strKeyOption;
    }
Translate an option to a proper url value to be used in the filter url.

Overriding this method allows to toggle the value in the url in addition to extract
or inject a value into an "combined" filter url parameter (like tags i.e.)

@param array  $arrWidget    The widget information.

@param array  $arrFilterUrl The filter url parameters to use.

@param string $strKeyOption The option value to determine.

@return string The filter url value to use for link gererating.