Redux-thunk 输入的默认值

Question

我有一个带有 thunk 的简单 SPA。它使用 github API 来获取回购列表。我之前有一个带有 class 演示组件的示例。它有一个本地状态，但我决定尽可能简化示例并将其重构为正常运行并删除本地状态并使用 ref 获取输入值。效果很好

如何在输入字段中设置默认值，以便在应用加载时获取该值。
我不太明白如何删除 combineReducers 并使用单个 reducer，就像我将 createStore 与单个 reducer 应用程序中断时一样

代码如下： https://codesandbox.io/s/k13nowrj33

import React, { Component } from "react";
import ReactDOM from "react-dom";
import { applyMiddleware, combineReducers, createStore } from "redux";
import { connect, Provider } from "react-redux";
import thunk from "redux-thunk";
import "./index.css";

// actions.js
const addRepos = repos => ({ type: "ADD_REPOS", repos });
const clearRepos = () => ({ type: "CLEAR_REPOS" });
const getRepos = username => async dispatch => {
  try {
    const url = `https://api.github.com/users/${username}/repos`;
    const response = await fetch(url);
    const responseBody = await response.json();
    dispatch(addRepos(responseBody));
  } catch (error) {
    console.log(error);
    dispatch(clearRepos());
  }
};

// reducers.js
const repos = (state = [], action) => {
  switch (action.type) {
    case "ADD_REPOS":
      return action.repos;
    case "CLEAR_REPOS":
      return [];
    default:
      return state;
  }
};

const rootreducer = combineReducers({ repos });

const store = createStore(rootreducer, applyMiddleware(thunk));

// App.js
function App(props) {
  var textInput;
  var setTextInputRef = element => { textInput = element; };
  var submit = () => props.getRepos(textInput.value);
  return (
    <div>
      <h1>Github username: </h1>
      <input type="text" ref={setTextInputRef} />
      <button onClick={submit}>Get All Repos</button>
      <ul>
        {props.repos.map((repo, index) => (<li key={index}><a href={repo.html_url}>{repo.name}</a></li> ))}
      </ul>
    </div>
  );
}

// AppContainer.js
const mapStateToProps = state => ({ repos: state.repos });
const mapDispatchToProps = { getRepos };
const AppContainer = connect(mapStateToProps, mapDispatchToProps)(App);

ReactDOM.render(<Provider store={store}><AppContainer /></Provider>, document.getElementById("root"));

Answer 1

1.) 您可以使用 defaultValue 来达到这个目的。

2.) 如评论中所述，如果您不使用 combineReducers()，则需要更改 mapStateToProps()。

这是一种方法：

import React, { Component } from "react";
import ReactDOM from "react-dom";
import { applyMiddleware, combineReducers, createStore } from "redux";
import { connect, Provider } from "react-redux";
import thunk from "redux-thunk";
import "./index.css";

// actions.js
const addRepos = repos => ({ type: "ADD_REPOS", repos });
const clearRepos = () => ({ type: "CLEAR_REPOS" });
const getRepos = username => async dispatch => {
  try {
    const url = `https://api.github.com/users/${username}/repos`;
    const response = await fetch(url);
    const responseBody = await response.json();
    dispatch(addRepos(responseBody));
  } catch (error) {
    console.log(error);
    dispatch(clearRepos());
  }
};

// reducers.js
const repos = (state = [], action) => {
  switch (action.type) {
    case "ADD_REPOS":
      return action.repos;
    case "CLEAR_REPOS":
      return [];
    default:
      return state;
  }
};

const store = createStore(repos, applyMiddleware(thunk));

// App.js
function App(props) {
  var textInput;
  var setTextInputRef = element => {
    textInput = element;
  };
  var submit = () => props.getRepos(textInput.value);
  return (
    <div>
      <h1>Github username: </h1>
      <input defaultValue="colinricardo" type="text" ref={setTextInputRef} />
      <button onClick={submit}>Get All Repos</button>
      <ul>
        {props.repos.map((repo, index) => (
          <li key={index}>
            <a href={repo.html_url}>{repo.name}</a>
          </li>
        ))}
      </ul>
    </div>
  );
}

// AppContainer.js
const mapStateToProps = state => ({ repos: state });

const mapDispatchToProps = { getRepos };
const AppContainer = connect(
  mapStateToProps,
  mapDispatchToProps
)(App);

ReactDOM.render(
  <Provider store={store}>
    <AppContainer />
  </Provider>,
  document.getElementById("root")
);

CodeSandbox here.

要在加载时获取回购协议：

import React, { Component } from "react";
import ReactDOM from "react-dom";
import { applyMiddleware, combineReducers, createStore } from "redux";
import { connect, Provider } from "react-redux";
import thunk from "redux-thunk";
import "./index.css";

// actions.js
const addRepos = repos => ({ type: "ADD_REPOS", repos });
const clearRepos = () => ({ type: "CLEAR_REPOS" });
const getRepos = username => async dispatch => {
  try {
    const url = `https://api.github.com/users/${username}/repos`;
    const response = await fetch(url);
    const responseBody = await response.json();
    dispatch(addRepos(responseBody));
  } catch (error) {
    console.log(error);
    dispatch(clearRepos());
  }
};

// reducers.js
const repos = (state = [], action) => {
  switch (action.type) {
    case "ADD_REPOS":
      return action.repos;
    case "CLEAR_REPOS":
      return [];
    default:
      return state;
  }
};

const store = createStore(repos, applyMiddleware(thunk));

// App.js
class App extends React.Component {
  componentDidMount() {
    this.submit();
  }

  submit = () => this.props.getRepos(this.textInput.value);

  render() {
    return (
      <div>
        <h1>Github username: </h1>
        <input
          defaultValue="colinricardo"
          type="text"
          ref={ref => (this.textInput = ref)}
        />
        <button onClick={this.submit}>Get All Repos</button>
        <ul>
          {this.props.repos.map((repo, index) => (
            <li key={index}>
              <a href={repo.html_url}>{repo.name}</a>
            </li>
          ))}
        </ul>
      </div>
    );
  }
}
// AppContainer.js
const mapStateToProps = state => ({ repos: state });

const mapDispatchToProps = { getRepos };
const AppContainer = connect(
  mapStateToProps,
  mapDispatchToProps
)(App);

ReactDOM.render(
  <Provider store={store}>
    <AppContainer />
  </Provider>,
  document.getElementById("root")
);

Redux-thunk 输入的默认值

Default value for Redux-thunk input

reactjs

redux

redux-thunk

react-redux