/
OnChange.swift
43 lines (35 loc) · 1.38 KB
/
OnChange.swift
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import ComposableArchitecture
extension Reducer {
public func onChange<LocalState>(
of toLocalState: @escaping (State) -> LocalState,
perform additionalEffects: @escaping (LocalState, inout State, Action, Environment) -> Effect<
Action, Never
>
) -> Self where LocalState: Equatable {
.init { state, action, environment in
var previousLocalState = toLocalState(state)
defer { previousLocalState = localState }
let effects = self.run(&state, action, environment)
let localState = toLocalState(state)
return previousLocalState != localState
? .merge(effects, additionalEffects(localState, &state, action, environment))
: effects
}
}
public func onChange<LocalState>(
of toLocalState: @escaping (State) -> LocalState,
perform additionalEffects: @escaping (LocalState, LocalState, inout State, Action, Environment)
-> Effect<Action, Never>
) -> Self where LocalState: Equatable {
.init { state, action, environment in
var previousLocalState = toLocalState(state)
defer { previousLocalState = localState }
let effects = self.run(&state, action, environment)
let localState = toLocalState(state)
return previousLocalState != localState
? .merge(
effects, additionalEffects(previousLocalState, localState, &state, action, environment))
: effects
}
}
}