rum does not currently offer a way to *not* escape attribute values

[jf]

as alluded to in #265, values that require not escaping are basically impossible to create right now. Attribute values are always escaped. You can :dangerouslySetInnerHTML... but that is on inner HTML, and not on an attribute value.

One could do :dangerouslySetInnerHTML on the parent of whatever tag you need an attribute value to not be escaped.. but you would end up having to possibly and probably un-protect a whole lot of elements.