Can you give a more concrete example of what you want to achieve but currently is not possible?
I’m not sure if I understand what you want to say.
But it sounds as if you want to validate if a combination of fields is still valid even when only one has been changed?
Lets say the sum of :a and :b always have to be 10?
Shoouldn’t that be easily possible by a custom validator?
Something like:
if get_field(cs, :a) + get_field(cs, :b) != 10 do
cs
|> add_error(:a, "Must sum to 10", [other: :b])
|> add_error(:b, "Must sum to 10", [other: :a])
else
cs
end
