redux saga选择器,我如何从传奇中访问状态？

Question

之前已经提出了类似的问题,但答案对我没有任何帮助.

redux中的选择器是什么？

如何从redux-saga函数中的状态/商店中获取内容？

我认为我有一个不同的设置,因为我似乎无法从我的传奇访问状态.

我试过做:

const getList = store => store;
const getList = state=> state;

这些都回归了undefined.

我的商店看起来像这样......

export default function createStoreWithMiddleware() {
    const sagaMiddleware = createSagaMiddleware();
    const loggerMiddleware = createLogger();
    const middleware = [sagaMiddleware, loggerMiddleware];
    const persistedState = localStorage.getItem('reduxState') ? JSON.parse(localStorage.getItem('reduxState')) : {};

    const store = createStore(reducer, persistedState, compose(
        applyMiddleware(...middleware)
    ));

    store.subscribe(() => {
        localStorage.setItem('reduxState', JSON.stringify(store.getState()));
    });

    sagaMiddleware.run(rootSaga);

    return store;
}

我想在这个传奇中访问我的列表:

function* selectTender(action) {
    try {
        const response = yield Api.getTenderById(action.payload);
        yield put({type: 'SELECT_TENDER_SUCCEEDED', currentTender: response});
        const list = yield select(getList);
        yield put({type: 'FETCH_CHAPTERS', chaptersList: list, tenderId: response.id});
    } catch (err) {
        yield put({type: 'SELECT_TENDER_FAILED', message: err.message});
    }
}

export function* watchSelectTender(){
    yield takeEvery('SELECT_TENDER', selectTender);
}

但就像我说的,无论是state和store是不确定的.

那么,如何在传奇中访问我的商店(或州)？

Answer 1

你必须使用选择器.我举一个简单的例子.创建一个文件selectors.js并添加要从商店中选择的字段,如下所示.

export const username = (state) => state.user.name;

然后在你的传奇中,将选择器导入为,

import * as selectors from './selectors';

当你需要username在你的传奇中,你可以简单地做,

import {select} from 'redux-saga/effects';
...
...
function *sampleSaga(params) {
   const username = yield select(selectors.username);
}

不断username在sampleSaga现在将举行从国家的用户名值.