启用CORS
我是React的新手,请记住这一点。出于学习目的,我构建了一个简单的React + Redux应用程序,该应用程序以JSON格式从外部API获取数据。
如果我在Chrome中手动启用CORS(通过扩展程序),一切正常。
现在,我将应用程序部署到Heroku,我需要永久启用CORS才能访问API。显然这比我想象的要复杂得多!
这是我的代码:
server.js
const express = require('express');
const port = process.env.PORT || 8080;
const app = express();
const path = require('path');
const cors = require('cors');
app.use(cors());
app.use(express.static(__dirname + '/'));
app.get('*', (req, res) => {
res.sendFile(path.resolve(__dirname, 'index.html'));
});
app.listen(port);
console.log("server started");
SRC / index.js
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 App from './components/app';
import reducers from './reducers';
const createStoreWithMiddleware = applyMiddleware(ReduxPromise)(createStore);
ReactDOM.render(
<Provider store={createStoreWithMiddleware(reducers)}>
<App />
</Provider>
, document.querySelector('.container'));
SRC /动作/ index.js
import axios from 'axios';
const API_KEY = "********************************";
export const SEARCH_URL = `=${API_KEY}`;
export const FETCH_RECIPES = "FETCH_RECIPES";
export function fetchRecipes(searchTerm) {
const url = `${SEARCH_URL}&q=${searchTerm}`;
const request = axios.get(url);
return {
type: FETCH_RECIPES,
payload: request
};
}
有任何想法吗?
回答如下:您需要在服务器端启用cors,在那里发出请求,不可能从客户端覆盖cors设置,只有少数例外。