Redux-Thunk

Question

我正在尝试发送一个动作。我找到了一些操作的工作示例，但没有我的那么复杂。

你能给我一个提示吗？我做错了什么？

我正在使用 TypeScript，最近删除了所有类型并尽可能简化了我的代码。

我正在使用 redux-thunk 和 redux-promise，像这样：

import { save } from 'redux-localstorage-simple';
import thunkMiddleware from 'redux-thunk';
import promiseMiddleware from 'redux-promise';

const middlewares = [
        save(),
        thunkMiddleware,
        promiseMiddleware,
    ];
const store = createStore(
        rootReducer(appReducer),
        initialState,
        compose(
            applyMiddleware(...middlewares),
            window['__REDUX_DEVTOOLS_EXTENSION__'] ? window['__REDUX_DEVTOOLS_EXTENSION__']() : f => f,
        ),
    );

组件 - Foo 组件：

import actionFoo from 'js/actions/actionFoo';
import React, { Component } from 'react';
import { connect } from 'react-redux';

class Foo {
    constructor(props) {
        super(props);
        this._handleSubmit = this._handleSubmit.bind(this);
    }
    _handleSubmit(e) {
        e.preventDefault();
        this.props.doActionFoo().then(() => {
            // this.props.doActionFoo returns undefined
        });
    }
    render() {
        return <div onClick={this._handleSubmit}/>;
    }
}

const mapStateToProps = ({}) => ({});

const mapDispatchToProps = {
    doActionFoo: actionFoo,
};

export { Foo as PureComponent };
export default connect(mapStateToProps, mapDispatchToProps)(Foo);

动作 - actionFoo:

export default () => authCall({
    types: ['REQUEST', 'SUCCESS', 'FAILURE'],
    endpoint: `/route/foo/bar`,
    method: 'POST',
    shouldFetch: state => true,
    body: {},
});

操作 - AuthCall：

// extremly simplified
export default (options) => (dispatch, getState) => dispatch(apiCall(options));

操作 - ApiCall：

export default (options) => (dispatch, getState) => {
    const { endpoint, shouldFetch, types } = options;

    if (shouldFetch && !shouldFetch(getState())) return Promise.resolve();

    let response;
    let payload;

    dispatch({
        type: types[0],
    });

    return fetch(endpoint, options)
        .then((res) => {
            response = res;
            return res.json();
        })
        .then((json) => {
            payload = json;

            if (response.ok) {
                return dispatch({
                    response,
                    type: types[1],
                });
            }
            return dispatch({
                response,
                type: types[2],
            });
        })
        .catch(err => dispatch({
            response,
            type: types[2],
        }));
};

Answer 1

来自redux-thunk

Redux Thunk middleware allows you to write action creators that return a function instead of an action

所以这意味着它不处理您的承诺。您必须添加 redux-promise 才能支持

The default export is a middleware function. If it receives a promise, it will dispatch the resolved value of the promise. It will not dispatch anything if the promise rejects.

redux-thunk 与 redux-promise 之间的差异你可以阅读

Answer 2

好吧，几个小时后，我找到了解决办法。 redux-thunk 必须先于任何其他中间件。因为中间件是从右到左调用的，所以 redux-thunk return 在链的最后，因此 return 是 Promise。

import thunkMiddleware from 'redux-thunk';

const middlewares = [
        thunkMiddleware,
        // ANY OTHER MIDDLEWARE,
    ];
const store = createStore(
        rootReducer(appReducer),
        initialState,
        compose(
            applyMiddleware(...middlewares),
            window['__REDUX_DEVTOOLS_EXTENSION__'] ? window['__REDUX_DEVTOOLS_EXTENSION__']() : f => f,
        ),
    );

Redux-Thunk - 异步动作创建者承诺和链接不起作用

Redux-Thunk - Async action creators Promise and chaining not working

javascript

reactjs

redux

redux-promise