Javascript 在 redux-saga 中获取状态？
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getState in redux-saga?
提问by Andy Ray
I have a store with a list of items. When my app first loads, I need to deserialize the items, as in create some in-memory objects based on the items. The items are stored in my redux store and handled by an itemsReducer.
我有一个商店，里面有商品清单。当我的应用程序第一次加载时，我需要反序列化这些项目，就像基于这些项目创建一些内存中的对象一样。这些项目存储在我的 redux 存储中并由itemsReducer.
I'm trying to use redux-sagato handle the deserialization, as a side effect. On first page load, I dispatch an action:
作为副作用，我正在尝试使用redux-saga来处理反序列化。在第一页加载时，我调度一个动作：
dispatch( deserializeItems() );
My saga is set up simply:
我的传奇设置很简单：
function* deserialize( action ) {
// How to getState here??
yield put({ type: 'DESERISLIZE_COMPLETE' });
}
function* mySaga() {
yield* takeEvery( 'DESERIALIZE', deserialize );
}
In my deserialize saga, where I want to handle the side effect of creating in-memory versions of my items, I need to read the existing data from the store. I'm not sure how to do that here, or if that's a pattern I should even be attempting with redux-saga.
在我的反序列化传奇中，我想处理创建项目的内存版本的副作用，我需要从存储中读取现有数据。我不知道如何在这里做到这一点，或者如果这是我什至应该尝试使用 redux-saga 的模式。
回答by Kokovin Vladislav
you can use select effect
您可以使用选择效果
import {select, ...} from 'redux-saga/effects'
function* deserialize( action ) {
const state = yield select();
....
yield put({ type: 'DESERIALIZE_COMPLETE' });
}
also you can use it with selectors
您也可以将它与选择器一起使用
const getItems = state => state.items;
function* deserialize( action ) {
const items = yield select(getItems);
....
yield put({ type: 'DESERIALIZE_COMPLETE' });
}
回答by Alex Shwarc
Select effect does not help us if we in a callback functions, when code flow is not handled by Saga. In this case just pass dispatchand getStateto root saga:
如果我们在回调函数中，当 Saga 不处理代码流时，选择效果对我们没有帮助。在这种情况下，只需传递dispatch和getStateroot saga：
store.runSaga(rootSaga, store.dispatch, store.getState)
And the pass parameters to child sagas
和传递参数给子传奇
export default function* root(dispatch, getState) {
yield all([
fork(loginFlow, dispatch, getState),
])
}
export default function* root(dispatch, getState) {
yield all([
fork(loginFlow, dispatch, getState),
])
}
And then in watch methods
然后在 watch 方法中
export default function* watchSomething(dispatch, getState)
...
export default function* watchSomething(dispatch, getState)
...
