React redux saga - 出现一些奇怪的行为

Question

我正在学习如何使用 reactjs、redux、react-redux 和 redux-saga。我在我的 public github 存储库中尝试这样做，可在此处找到：

https://github.com/latheesan-k/react-redux-saga/tree/5cede54a4154740406c132c94684aae1d07538b0

我的store.js:

import { compose, createStore, applyMiddleware } from "redux";
import createSagaMiddleware from "redux-saga";

import reducer from "./reducers";
import mySaga from "./sagas";

const sagaMiddleware = createSagaMiddleware();

const composeEnhancers =
  typeof window === "object" && window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__
    ? window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({
        // TODO: Specify extension’s options like name, actionsBlacklist, actionsCreators, serialize...
      })
    : compose;

const storeEnhancer = composeEnhancers(applyMiddleware(sagaMiddleware));

export default createStore(reducer, storeEnhancer);

sagaMiddleware.run(mySaga);

我的actions.js

export const HELLO_WORLD_REQUEST = "HELLO_WORLD_REQUEST";
export const HELLO_WORLD_RESPONSE = "HELLO_WORLD_RESPONSE";
export const HELLO_WORLD_ERROR = "HELLO_WORLD_ERROR";

export const helloWorldRequest = () => ({ type: HELLO_WORLD_REQUEST });
export const helloWorldResponse = text => ({ type: HELLO_WORLD_RESPONSE, text });
export const helloWorldError = error => ({ type: HELLO_WORLD_ERROR, error });

和我的sagas.js

import { put, takeLatest } from "redux-saga/effects";

import { HELLO_WORLD_REQUEST, helloWorldResponse, helloWorldError } from "./actions";

function* runHelloWorldRequest(action) {
  try {
    // TODO: real api call here
    yield put(helloWorldResponse("Hello from react-redux-saga :)"));
  } catch (e) {
    yield put(helloWorldError(e));
  }
}

export default function* mySaga() {
  yield takeLatest(HELLO_WORLD_REQUEST, runHelloWorldRequest);
}

和我的helloWorldReducer.js

import { HELLO_WORLD_RESPONSE } from "../actions";

export default (state = "", { type, text }) => {
  switch (type) {
    case HELLO_WORLD_RESPONSE:
      return text;

    default:
      return state;
  }
};

这就是如何将它们放在我的 App 组件中：

class App extends Component {
  componentDidMount() {
    this.props.helloWorldRequest();
  }

  render() {
    return (
      <div className="App">
        <header className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <p>{this.props.responseText}</p>
        </header>
      </div>
    );
  }
}

const mapStateToProps = state => ({ responseText: state.helloWorldReducer });
const mapDispatchToProps = dispatch => bindActionCreators({ helloWorldRequest }, dispatch);

export default connect(
  mapStateToProps,
  mapDispatchToProps
)(App);

这工作正常，但这是我试图理解的奇怪行为。为了从状态中获取响应值并将其映射到道具中，我必须这样做：

const mapStateToProps = state => ({ responseText: state.helloWorldReducer });

基于我在 react devtools 中看到的：

处理请求并生成响应后的通知；生成的状态对象包含一个名为 helloWorldReducer 的字段。

这是从哪里来的？

我假设这个字段名称应该被称为 text.

P.S。很抱歉 post;仍在学习 react-redux-saga，所以我不知道我的代码的哪一部分与手头的问题相关。

Answer 1

the resulting state object contains a field called helloWorldReducer.

Where did this come from?

它来自你的root reducer，它实际上是使用combineReducers()方法创建的reducer。

这是您的 reducers/index.js 文件，它导出用于创建 redux 存储的根减速器：

import { combineReducers } from "redux";

import helloWorldReducer from "./helloWorldReducer";

export default combineReducers({
  helloWorldReducer   // here
});

React redux saga - 出现一些奇怪的行为

React redux saga - getting some odd behaviour

reactjs

redux

redux-saga

react-redux