英文:
Using axios / fetch to fetch data from node toreact
问题
我明白你的问题。以下是有关如何从Node后端到React前端获取数据的问题的翻译部分:
在你的React代码中,你尝试了两种方法来从Node后端获取数据,但遇到了问题。
第一种方法出现了401未授权错误,这可能是因为你的请求没有正确的身份验证。你需要确保在请求中包括有效的身份验证令牌(token)。你可以检查你的身份验证逻辑,确保令牌被正确设置并发送到后端。
第二种方法没有在控制台中返回任何内容,这可能是因为你没有正确地处理响应。在你的fetchData
函数中,你可以尝试以下修改:
const fetchData = async () => {
try {
const response = await fetch("http://localhost:4000/api/jobs", {
method: "GET",
headers: {
"Content-Type": "application/json",
Accept: "application/json",
"Access-Control-Allow-Credentials": true,
"Access-Control-Allow-Origin": true,
credentials: "same-origin",
Authorization: `Bearer ${token}`,
},
});
if (!response.ok) {
throw new Error("Network response was not ok");
}
const newData = await response.json();
console.log(newData);
setName(newData.jobs.name);
} catch (error) {
console.error("Fetch error:", error);
}
};
fetchData();
这个修改将首先检查响应是否成功,如果不成功,则抛出一个错误。这有助于更好地处理错误情况并提供更多的信息来调试问题。
请确保在使用第二种方法时,你的token
变量已经被定义和设置为有效的身份验证令牌。
希望这些修改能帮助你解决问题,成功获取数据从后端到前端。如果你需要进一步的帮助,请提供更多的信息。
英文:
Please I need a help on how to fetch a data from node to react, I have been stuck here for 2 weeks now.
Here are my backend code:
server.js
:
require("dotenv").config();
const app = require("./src/app");
const port = process.env.PORT || 4000;
app.get("/", (req, res) => {
res.send("Hello World!");
});
app.listen(port, () => {
console.log(`Server is running on port http://localhost:${port}`);
});
app.js
:
const express = require("express");
const cors = require("cors");
const cookieSession = require("cookie-session");
const app = express();
app.use(
cors({
origin: ["http://localhost:4000/api", "http://localhost:3000"],
})
);
app.use(function (req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header(
"Access-Control-Allow-Headers",
"Origin, X-Requested-With, Content-Type, Accept"
);
next();
});
app.use(express.json());
app.use(express({ type: "application/vnd.api+json" }));
app.use(express.urlencoded({ extended: true }));
app.use(
cookieSession({
name: process.env.COOKIE_NAME, //ookie name in .env
secret: process.env.COOKIE_SECRET, //secret name in .env
httpOnly: true,
sameSite: "strict",
maxAge: 24 * 60 * 60 * 1000, // 24 hours duration before expire
})
);
app.use("/uploads", express.static("uploads"));
const jobRoute = require("./routes/job.routes");
app.use("/api/", jobRoute);
module.exports = app;
service.js
:
const db = require("../config/database");
const notificationServices = require("./notification.services");
const { jobReuseQuery } = require("../job reuseable query/job.queries");
const createJob = async (body) => {
const {
title,
salary_type,
salary,
job_types,
description,
company_id,
sector_id,
category_id,
} = body;
const { rows } = await db.query(
`INSERT INTO jobs (title, salary_type, salary, job_types, description, company_id, sector_id, category_id)
VALUES ($1, $2, $3, $4, $5, $6, $7, $8) RETURNING *`,
[
title,
salary_type,
salary,
job_types,
description,
company_id,
sector_id,
category_id,
]
);
notificationServices.sendMatchJobsToUserProfiles(rows[0]);
return rows[0];
};
const getAllJobs = async () => {
const { rows } = await db.query("SELECT * FROM jobs");
return rows;
};
controller.js
:
const jobService = require("../services/job.services");
const createJob = async (req, res) => {
try {
const job = await jobService.createJob(req.body);
res.status(201).send({
message: "Job created successfully",
data: job,
});
} catch (err) {
res.status(400).send(err.message);
}
};
const getAllJobs = async (req, res) => {
try {
const jobs = await jobService.getAllJobs();
res.status(200).send({ data: jobs });
} catch (err) {
res.status(400).send({ message: err.message });
}
};
routes.js
:
const router = require("express-promise-router")();
const jobController = require("../controllers/job.controller");
const auth = require("../middleware/auth.middleware");
router.post("/jobs", auth, jobController.createJob);
auth.js
:
const db = require("../config/database");
const jwt = require("jsonwebtoken");
const dotenv = require("dotenv");
dotenv.config();
const auth = async (req, res, next) => {
const token = req.session.token;
if (!token) {
return res.status(401).send({ error: "Please Authenticate" });
}
try {
const decoded = jwt.verify(token, process.env.JWT_SECRET);
const { rows } = await db.query("SELECT * FROM users WHERE id = $1", [
decoded.id,
]);
if (!rows[0]) {
throw new Error("User not found");
}
req.user = rows[0];
next();
} catch (error) {
return res.status(401).send({ error: error.message });
}
};
module.exports = auth;
React frontend code:
import React, { useEffect } from "react";
import tech from "../../image/tech-big.svg";
import health from "../../image/health-big.svg";
import eng from "../../image/eng-big.svg";
import axios from "axios";
import { useState } from "react";
const Joblist = () => {
const [name, setName] = useState([]);
//first method
const response = axios
.get("http://localhost:4000/api/jobs/")
.then((res) => res.json());
console.log(response);
//second method
const fetchData = async () => {
const newData = await fetch("http:localhost:4000/api/jobs", {
method: "GET",
headers: {
"Content-Type": "application/json",
ACCEPT: "application/json",
"Access-Control-Allow-Credentials": true,
"Access-Control-Allow-Origin": true,
credentials: "same-origin",
Authorization: `Bearer ${token}`,
},
}).then((res) => res.json());
console.log(newData);
setName(newData.jobs.name);
fetchData();
};
you can see in my react, I have 2 method i used trying to fetch the data fron node to the react
first method return error in my browser console :
Promise {<pending>}
GET http://localhost:4000/api/jobs/ 401 (Unauthorized)
Uncaught (in promise) AxiosError {message: 'Request failed with status code 401', name: 'AxiosError', code: 'ERR_BAD_REQUEST', config: {…}, request: XMLHttpRequest, …}
while the second method return nothing in my browser console
I am trying to fetch a data from my node backend into frontend react but my first method log error while the second method log nothing
答案1
得分: 0
我认为你需要稍微清理一下你的设置,因为你正在使用CORS,你可以首先进行一些更改:
// .....
const app = express();
// 使用CORS,你可以在同一个地方进行所有设置,所以不需要设置头信息
const corsOptions = {
origin: ["http://localhost:4000/api", "http://localhost:3000"],
methods: "GET, POST, PUT, DELETE, OPTIONS, HEAD",
credentials: true, // 用于JWT/cookie!
};
app.use(cors(corsOptions));
app.use(express.json());
app.use(express({ type: "application/vnd.api+json" }));
app.use(express.urlencoded({ extended: true }));
app.use(
cookieSession({
name: process.env.COOKIE_NAME,
secret: process.env.COOKIE_SECRET,
maxAge: 24 * 60 * 60 * 1000,
httpOnly: true,
sameSite: false, //如果部署到跨域生产环境,请设置为"None"。
secure: false, //如果在https的生产环境中需要,请设置为true
});
);
app.use("/uploads", express.static("uploads"));
const jobRoute = require("./routes/job.routes");
app.use("/api/", jobRoute);
module.exports = app;
更新fetch部分,我进行了清理(删除了头信息),我注意到你在job.controller.js中将数据属性放在了响应JSON中,所以你需要再次检查你的数据库结构是否正常工作。
useEffect(() => {
const fetchData = async () => {
try {
const response = await fetch("http:localhost:4000/api/jobs", {
credentials: "include", //以便能够发送带有cookies的请求...
});
if(response.ok) {
const newData = await response.json();
console.log(newData);
setName(newData.data.jobs.name); //这部分你需要再次检查你的数据结构...
}
} catch (error) {
console.log(error)
}
}
fetchData();
}, []);
可选注意事项:这部分不是你的问题的一部分,只是以防cookie-session和JWT令牌仍然存在问题,你可以更改JWT在cookie中的存储方式:cookie-session的目的是创建一个“会话ID”,通过在客户端(浏览器)上存储它(在cookie中)来进行用户身份验证,如果你要使用JWT令牌进行身份验证,我真的看不出为什么要使用它?如果你在这部分仍然遇到问题,你可以查看下面的步骤:
首先,你可能需要安装cookie-parser中间件,因为如果这种方法对你有效,你将能够卸载cookie-session。
const cookieParser = require('cookie-parser')
// ...
app.use(cookieParser());
在auth.controllers.js中:
const loginAuth = async (req, res) => {
try {
const token = await authServices.login(req.body);
// 在cookie中设置JWT令牌
res.cookie("jwt", token, {
maxAge: 24 * 60 * 60 * 1000,
httpOnly: true,
sameSite: false, //如果部署到跨域生产环境,请设置为"None"。
secure: false, //如果在https的生产环境中需要,请设置为true
})
return res.status(200).json({
//如果发送的请求体匹配,控制器将返回此消息
message: "用户登录成功!",
});
} catch (error) {
//否则将返回此错误消息
return res.status(500).json({ message: error.message });
}
};
// 为用户创建注销会话,将会话签名为空
const logoutAuth = async (req, res) => {
res.clearCookie("jwt")
return res.status(200).send({ message: "用户成功登出!" });
};
还需要在activeAuth函数中替换const token = req.session.token;
,在auth.middleware.js的auth中间件函数中替换为:
const token = req.cookies["jwt"] //或者
const token = req.cookies.jwt
最后,如果它工作了,你可以卸载cookie-session。
英文:
I think you need to clean up a bit your setting, since you're using CORS than you can first make some changes :
// .....
const app = express();
// with CORS you can do all your setting at the same place, so you don't need to set the header
const corsOptions = {
origin: ["http://localhost:4000/api", "http://localhost:3000"],
methods: "GET, POST, PUT, DELETE, OPTIONS, HEAD",
credentials: true, // for jwt/cookie !
};
app.use(cors(corsOptions));
app.use(express.json());
app.use(express({ type: "application/vnd.api+json" }));
app.use(express.urlencoded({ extended: true }));
app.use(
cookieSession({
name: process.env.COOKIE_NAME,
secret: process.env.COOKIE_SECRET,
maxAge: 24 * 60 * 60 * 1000,
httpOnly: true,
sameSite: false, //set this to "None" if you deploy to production on cross domaine.
secure: false, //set to true is required on production with https
});
app.use("/uploads", express.static("uploads"));
const jobRoute = require("./routes/job.routes");
app.use("/api/", jobRoute);
module.exports = app;
Update the fetch part I clean up (I remove the header) and i just notice on your job.controller.js you put data property on your response json.. so you need to check again your database structure if it's still not working.
useEffect(() => {
const fetchData = async () => {
try {
const response = await fetch("http:localhost:4000/api/jobs", {
credentials: "include", //to be able to send with cookies...
});
if(response.ok) {
const newData = await response.json();
console.log(newData);
setName(newData.data.jobs.name); // this part you need to check your data structure again...
}
} catch (error) {
console.log(error)
}
}
fetchData();
}, []);
Optional note: this part is not part of your question, just in case if there is still issue with the cookie-session and jwtoken, you can change how the JWT is stored in the cookie: cookie-session purpose is to create a "session id" to authenticate the user by storing it at the client side (on the browser, with the cookie), i don't really see the point to use this if you're gonna use jwt token to authenticate anyway ? I let you see the step below if you re still stuck at this part:
First, you may need to install cookie-parser middleware, because if this method work for you, you will be able to uninstall cookie-session.
const cookieParser = require('cookie-parser')
/...
app.use(cookieParser());
on the auth.controllers.js
const loginAuth = async (req, res) => {
try {
const token = await authServices.login(req.body);
// set the jwt token on the cookie
res.cookie("jwt", token, {
maxAge: 24 * 60 * 60 * 1000,
httpOnly: true,
sameSite: false, //set this to "None" if you deploy to production on cross domaine.
secure: false, //set to true is required on production with https
})
return res.status(200).json({
//controller will return this message if the body sent was match
message: "User logged in successfully!",
});
} catch (error) {
//ratther it will return this erroe message
return res.status(500).json({ message: error.message });
}
};
//create a logout session for the user to logout by signing session to null
const logoutAuth = async (req, res) => {
res.clearCookie("jwt")
return res.status(200).send({ message: "User logged out successfully!" });
};
You also need to replace const token = req.session.token;
in your activeAuth function, and in your auth.middleware.js at the auth middleware function by this:
const token = req.cookies["jwt"] //or
const token = req.cookies.jwt
Finally if it work you can uninstall cookie-session.
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