React Redux - 从reducer传递数据时容器/组件不更新

时间:2017-12-02 17:15:25

标签: javascript reactjs redux react-redux

我是React的新手,请记住这一点。

我尝试渲染从food2fork API获取的食谱列表,但即使数据被正确提取,我也无法获得更新视图。

这里的recipe_list.js:

import React, { Component } from "react";
import { connect } from "react-redux";

    class RecipesList extends Component {
    // renderRecipe(recipe) {
    //     console.log(recipe);
    //     return (
    //         <div>{recipe}</div>
    //     );
    // }

    render() {
        console.log("Render function ", this.props.recipes)
            return (
            <div>
                <p>Recipes</p>
                <div>{this.props.recipes}</div>
            </div>
            );
    }
}

function mapStateToProps(state){
    return { recipes: state.recipes };
}

export default connect(mapStateToProps)(RecipesList);

这里是reducer_recipes.js:

import FETCH_RECIPES from "../actions/index";

export default function(state = [], action){
    switch (action.type) {
        case FETCH_RECIPES:
            return action.payload;
    }
    return state;
}

这里&/reducers/index.js:

import { combineReducers } from 'redux';
import RecipesReducer from "./reducer_recipes";

console.log(RecipesReducer);
const rootReducer = combineReducers({
  recipes: RecipesReducer
});

export default rootReducer;

这里&#39; s /actions/index.js:

import axios from "axios";

const API_KEY = "****************************";
export const URL = `https://food2fork.com/api/search?key=${API_KEY}`;


export const FETCH_RECIPES = "FETCH_RECIPES";

export function fetchRecipes(term){
    const url = `${URL}&q=${term}`;
    const request = axios.get(url);

    return {
        type: FETCH_RECIPES,
        payload: request
    };
}

我没有收到任何具体错误。该视图不会更新。我试图在文件周围传播一些console.log,试图了解问题所在。 看起来Reducer没有成功地将有效负载传递给组件。

注意:我使用react-promise,因此axios返回的承诺会自动解决。

有什么想法吗?

============================================ =======================

修改

感谢您提供有用的链接,但显然我仍然缺少这些内容。 我修改了动作索引:

function getStuffSuccess(response) {
  return {
    type: FETCH_RECIPES,
    payload: response
  };
}

function getStuffError(err) {
  return {
    type: ERROR_FETCH_RECIPES,
    payload: err
  };
}

export function fetchRecipes(term) {
    const url = `${URL}&q=${term}`;

  return function(dispatch) {
    axios.get(url)
      .then((response) => {
        dispatch(getStuffSuccess(response));
      })
      .catch((err) => {
        dispatch(getStuffError(err));
      });
  };
}

我还在商店中加入了redux-thunk:

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import ReduxPromise from "redux-promise";
import Thunk from 'redux-thunk';

import App from './components/app';
import reducers from './reducers';

const createStoreWithMiddleware = applyMiddleware(Thunk, ReduxPromise)    (createStore);

ReactDOM.render(
  <Provider store={createStoreWithMiddleware(reducers)}>
    <App />
  </Provider>
  , document.querySelector('.container'));

这种行为从以前没有改变过。该视图仍未更新。

注意:如果我在控制台上记录了Reducer中的有效负载,那么数据就在那里。但是当我试图在视图中做同样的事情时,没有任何事情发生。

2 个答案:

答案 0 :(得分:0)

您的操作不是同步,您需要使用Async Action将响应传递给reducer,这意味着您必须dispatch响应而不是返回它。查看给定的链接以获取更多详细信息。

答案 1 :(得分:0)

我会尝试重构你的curl

/actions/index.js