javascript - 如何在 redux 中使用 axios 库将数据发布到 API 服务器

Question

我有一个 redux 表单，我从中检索数据并尝试将其发布到我的 API 服务器。我的 redux 表单的代码如下:

import React, { Component } from 'react';
import { Field, reduxForm } from 'redux-form';
import { Link } from 'react-router-dom';
import { connect } from 'react-redux';
import { createPosts } from '../actions/posts_action';

class CreatePost extends Component {
  constructor() {
    super();
    this.state = {
      selectValue : ''
  };
   this.renderCategory = this.renderCategory.bind(this);
}

  renderField(field) {
      return(
        <div className="title-design">
            <label className="label-design"> {field.label} </label>
            <input
              type="text"
              className="title-input"
              {...field.input}
            />
            <div className="text-help  has-danger">
              {field.meta.touched ? field.meta.error : ''}
            </div>
      </div>
      );
  }


  renderCategory(field) {
    return(
      <div className="title-design">
        <label className="label-design">{field.label} </label>
          <Field name="category" className="title-input" component="select">
            <option></option>
            <option value="react">React</option>
            <option value="redux">Redux</option>
            <option value="udacity">Udacity</option>
          </Field>

          <div className="text-help has-danger">
            {field.meta.touched ? field.meta.error : ''}
          </div>
      </div>
    );
  }

    onSubmit(values) {
      this.props.createPosts(values, () => {
          this.props.history.push('/');
      });
    }



    render() {
      const { handleSubmit } = this.props;

      return (
        <form onSubmit={handleSubmit(this.onSubmit.bind(this))}>
          <Field
            label="Title for Post"
            name="title"
            component={this.renderField}
          />

          <Field
            label="Post Content"
            name="body"
            component={this.renderField}
          />

          <Field
            label="Category"
            name="category"
            component={this.renderCategory}
            />

          <button type="submit" className="btn btn-primary">Submit</button>
          <Link  to="/">
            <button className="cancel-button">Cancel</button>
          </Link>
        </form>
      );
    }
}

function validate(values) {
  const errors = {} ;

  if (!values.title) {
      errors.title = "Enter a title";
  }

  if (!values.body) {
    errors.body = "Enter some content";
    }

  if(!values.category) {
    errors.category = "Please select a category";
  }
  return errors;
}

export default reduxForm({
  validate : validate,          //validate
  form : 'CreatePostForm'
})(
  connect(null,{ createPosts })(CreatePost)
);

我的用于将数据发布到 API 服务器的操作创建者是:

//Action Creator for creating posts
export function createPosts(values, callback) {
  const request = axios.post(`${API}/posts`,values,{headers})
    .then(() => callback());
    console.log(request);    
  return dispatch => {
    return request.then(({data}) => {
      dispatch({
        type: CREATE_POST,
        payload: data
      })
    })
  }
}

我用于创建帖子的reducer是:

import _ from 'lodash';
import { FETCH_POSTS, FETCH_POST, CREATE_POST } from '../actions/posts_action';

export default function(state = {}, action) {
  switch (action.type) {
    case FETCH_POST:
      // const post = action.payload.data;
      // const newState  = { ...state,  };
      // newState[post.id] = post;
      // return newState;
      return {...state, [action.payload.id]: action.payload};

    case FETCH_POSTS:
     return {posts: { ...state.posts, ...action.payload }};

    case CREATE_POST:
      return {posts: { ...state, ...action.payload}};

     default:
      return state;
  }

}

我的所有 reducer 组合在一起的索引文件是:

import { combineReducers } from 'redux';
import PostReducer from './PostsReducer';
import { reducer as formReducer} from 'redux-form';
import CategoriesReducer from './CategoriesReducer';

const rootReducer = combineReducers({
    posts: PostReducer,
    categories: CategoriesReducer,
    form : formReducer
});

export default rootReducer;

现在我面临的问题是，当我尝试提交表单数据时，出现如下屏幕截图所示的错误:

任何人都可以指导我做错了什么以及如何继续吗？

编辑1整个项目的代码index.js文件如下:

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import { BrowserRouter, Route } from 'react-router-dom';
import thunk from 'redux-thunk';
import './index.css';
import App from './App';
import reducers from './reducers/index.js'
import Posts from './components/posts_index';
import CreatePost from './components/new_post';
import PostDetail from './components/post_detail';
import CategoryView from './components/category';
import { compose } from 'redux';

//const createStoreWithMiddleware = createStore(reducers,applyMiddleware(thunk));

const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
 const createStoreWithMiddleware = createStore(reducers, composeEnhancers(applyMiddleware(thunk)));

ReactDOM.render(
  <Provider store={createStoreWithMiddleware}>
      <BrowserRouter>
        <div>
          <Route  path="/new" component={CreatePost} />
          <Route path="/posts/:id" component={PostDetail} />
          <Route exact  path="/" component={Posts} />
          <Route path="/:category/posts" component={CategoryView} />
        </div>
      </BrowserRouter>
  </Provider>  , document.getElementById('root'));

编辑2:

我还添加了以下 API 服务器的文件:

const clone = require('clone')

let db = {}

const defaultData = {
  "8xf0y6ziyjabvozdd253nd": {
    id: '8xf0y6ziyjabvozdd253nd',
    timestamp: 1467166872634,
    title: 'Udacity is the best place to learn React',
    body: 'Everyone says so after all.',
    author: 'thingtwo',
    category: 'react',
    voteScore: 6,
    deleted: false,
    commentCount: 2
  },
  "6ni6ok3ym7mf1p33lnez": {
    id: '6ni6ok3ym7mf1p33lnez',
    timestamp: 1468479767190,
    title: 'Learn Redux in 10 minutes!',
    body: 'Just kidding. It takes more than 10 minutes to learn technology.',
    author: 'thingone',
    category: 'redux',
    voteScore: -5,
    deleted: false,
    commentCount: 0
  }
}

function getData (token) {
  let data = db[token]
  if (data == null) {
    data = db[token] = clone(defaultData)
  }
  return data
}

function getByCategory (token, category) {
  return new Promise((res) => {
    let posts = getData(token)
    let keys = Object.keys(posts)
    let filtered_keys = keys.filter(key => posts[key].category === category && !posts[key].deleted)
    res(filtered_keys.map(key => posts[key]))
  })
}

function get (token, id) {
  return new Promise((res) => {
    const posts = getData(token)
    res(
      posts[id].deleted
        ? {}
        : posts[id]
    )
  })
}

function getAll (token) {
  return new Promise((res) => {
    const posts = getData(token)
    let keys = Object.keys(posts)
    let filtered_keys = keys.filter(key => !posts[key].deleted)
    res(filtered_keys.map(key => posts[key]))
  })
}

function add (token, post) {
  return new Promise((res) => {
    let posts = getData(token)

    posts[post.id] = {
      id: post.id,
      timestamp: post.timestamp,
      title: post.title,
      body: post.body,
      author: post.author,
      category: post.category,
      voteScore: 1,
      deleted: false,
      commentCount: 0
    }

    res(posts[post.id])
  })
}

function vote (token, id, option) {
  return new Promise((res) => {
    let posts = getData(token)
    post = posts[id]
    switch(option) {
        case "upVote":
            post.voteScore = post.voteScore + 1
            break
        case "downVote":
            post.voteScore = post.voteScore - 1
            break
        default:
            console.log(`posts.vote received incorrect parameter: ${option}`)
    }
    res(post)
  })
}

function disable (token, id) {
    return new Promise((res) => {
      let posts = getData(token)
      posts[id].deleted = true
      res(posts[id])
    })
}

function edit (token, id, post) {
    return new Promise((res) => {
        let posts = getData(token)
        for (prop in post) {
            posts[id][prop] = post[prop]
        }
        res(posts[id])
    })
}

function incrementCommentCounter(token, id, count) {
  const data = getData(token)
  if (data[id]) {
    data[id].commentCount += count
  }
}

module.exports = {
  get,
  getAll,
  getByCategory,
  add,
  vote,
  disable,
  edit,
  getAll,
  incrementCommentCounter
}

Answer 1

更新:为 Action 创建者尝试此格式。 :

export function createPosts(values, callback) {

  return dispatch => { //return function
    return axios.post(`${API}/posts`,values,{headers}) //return post request response
    .then((data) => { //pass data in as a parameter, call the callback, dispatch the action. 
        callback();

      dispatch({
        type: CREATE_POST,
        payload: data
      })
    })
  }
}