observe abstract method
void
observe(
- ReduxAction<St> action,
- St prevState,
- St newState,
- Object? error,
- int dispatchCount,
)
-
action
= The action itself.
-
prevState
= The state right before the new state returned by the reducer is applied.
Note this may be different from the state when the reducer was called.
-
newState
= The state returned by the reducer. Note: If you need to know if the state was
changed or not by the reducer, you can compare both states:
bool ifStateChanged = !identical(prevState, newState);
-
error
= Is null if the reducer completed with no error and returned. Otherwise, will be the
error thrown by the reducer (before any wrapError is applied). Note that, in case of
error, both prevState and newState will be the current store state when the error
was thrown.
-
dispatchCount
= The sequential number of the dispatch.
Implementation
void observe(
ReduxAction<St> action,
St prevState,
St newState,
Object? error,
int dispatchCount,
);