sqAttribute constant Null safety
Escaping mode for text going into single-quoted HTML attribute values.
The result should not be used as the content of an unquoted or double-quoted attribute value.
Escapes single quotes (
') but not double quotes (
> characters because they are not allowed
in strict XHTML attributes
static const HtmlEscapeMode sqAttribute = HtmlEscapeMode._('attribute', true, false, true, false);