framework/i18n/Formatter.php
public function asHtml($value, $config = null)
    {
        if ($value === null) {
            return $this->nullDisplay;
        }

        return HtmlPurifier::process($value, $config);
    }
public function asHtml($value, $config = null)
    {
        if ($value === null) {
            return $this->nullDisplay;
        }

        return HtmlPurifier::process($value, $config);
    }
Formats the value as HTML text.
The value will be purified using [[HtmlPurifier]] to avoid XSS attacks.
Use [[asRaw()]] if you do not want any purification of the value.
@param string $value the value to be formatted.
@param array|null $config the configuration for the HTMLPurifier class.
@return string the formatted result.