sqAttribute constant Null safety

HtmlEscapeMode const sqAttribute

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 ("), and escapes < and > characters because they are not allowed in strict XHTML attributes

Implementation

static const HtmlEscapeMode sqAttribute =
    HtmlEscapeMode._('attribute', true, false, true, false);