LeOS-Ice-browser/docs/architectureexample/HistoryStorageMiddlewareExa...

40 lines
1.5 KiB
Kotlin
Executable File

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// This is example code for the 'Simplified Example' section of
// /docs/architecture-overview.md
class HistoryStorageMiddleware(
private val storage: HistoryStorage
private val scope: CoroutineScope,
) : Middleware<HistoryState, HistoryAction> {
override fun invoke(
context: MiddlewareContext<HistoryState, HistoryAction>,
next: (HistoryAction) -> Unit,
action: HistoryAction,
) {
// This middleware won't need to manipulate the action, so the action can be passed through
// the middleware chain before the side-effects are initiated
next(action)
when(action) {
is HistoryAction.Init -> {
scope.launch {
val history = storage.load()
context.store.dispatch(HistoryAction.ItemsChanged(history))
}
}
is HistoryAction.DeleteItems -> {
scope.launch {
val currentItems = context.state.items
if (storage.delete(action.items) is HistoryStorage.Success) {
context.store.dispatch(
HistoryAction.DeleteFinished()
)
}
}
}
else -> Unit
}
}
}