对 glitch.me 服务器的跨源请求

Question

我在 glitch.me 上创建了一个服务器，我正在尝试从该服务器提供数据，但出现了以下错误。本地主机/:1 对“https://clem-quote-server.glitch.me/quotes' from origin 'http://localhost:3000”处的提取访问已被 CORS 策略阻止：

No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

不太确定如何解决这个问题

import React, {Component} from "react"

class quotes extends Component {
    constructor(props) {
        super(props);
        this.state = {
            error: null,
            isLoaded: false,
            quotes: quotes
        };
    }

componentDidMount() {
    fetch("https://clem-quote-server.glitch.me/quotes")
      .then(res => res.json())
      .then(
        (result) => {
            this.setState({
            isLoaded: true,
              quotes: result.quotes
          });
        },
        error => {
          this.setState({
            isLoaded: true,
            error
          });
        }
      );
}

    render() {
        const { error, isLoaded, quotes } = this.state;
        if (error) {
            return <div>Error: {error.message}</div>;
        } else if (!isLoaded) {
            return <div>Loading...</div>;
        } else {
            return (
              <ul>
                {quotes.map(quote => {
                    return quote;

                }  
                )}
              </ul>
            );
        }
    }
}       
    export default quotes;

我希望每次加载页面时都能显示数组列表中的一个对象

Answer 1

由于 CORS 而失败，当服务器和客户端处理不同的域时必须包含它。

CORS 包含在 headers。

以下是如何在您的 React 应用中启用 corse：

https://facebook.github.io/create-react-app/docs/proxying-api-requests-in-development

CORS 信息：

https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS

对 glitch.me 服务器的跨源请求

Cross-origin request to glitch.me server

node.js

cors

glitch-framework