Allow substates to redefine/overwrite vars

[benedikt-bartscher]

Quote from @masenf in #3805

The other big problem I see in state.py is that substates cannot redefine or override fields from a parent state. Maybe this restriction doesn't make sense anymore... if a substate redefines a field, then it should be a different value than the same-named field in a parent state, but that's just not how the code is written today.

[masenf]

related to [REF-2300]

[benedikt-bartscher]

@masenf wdyt about emitting an error/warning first? Overwriting vars could introduce more unexpected behavior and is not trivial to solve. We could add it as a feature later on if we need it

[masenf]

i think it already does raise an error right?

import reflex as rx


class State(rx.State):
    foo: str = "bar"


class SubState(State):
    foo: str = "baz"


app = rx.App()
app.add_page(rx.logo, route="/")

reflex.utils.exceptions.VarNameError: State var "foo" in <class 'repro_overwrite.repro_overwrite.State'> has been shadowed by a substate var; use a different field name instead".

[benedikt-bartscher]

iirc it only does for base vars, not for computed vars

[benedikt-bartscher]

#3843