[英]Cors error when sending data from front-end client side react component to node.js server
我正在嘗試將數據從下面的客戶端反應組件發送到我的 node.js 服務器。 在我的控制台中,它顯示數據正在從客戶端傳遞到服務器。 但是,我收到以下 cors 錯誤:
跨域請求被阻止:同源策略不允許讀取位於 http://localhost:4000/ 的遠程資源。 (原因:缺少 CORS 標頭“Access-Control-Allow-Origin”)。 狀態碼:200。
我不知道為什么我仍然得到這個,因為我需要並在下面實現了 cors,以及 put res.setHeader("Access-Control-Allow-Origin", "*"); 在發布請求中。
任何幫助將不勝感激! 謝謝 :)
更新
我通過啟用 cors 中間件 app.use(cors()) 解決了這個問題
節點 server.js 文件
const express = require("express");
const cors = require("cors");
const app = express();
const port = 4000;
app.post("/", cors(), (req, res) => {
res.setHeader("Access-Control-Allow-Origin", "*");
const emailInfo = req.body.emailUserInput;
console.log(emailInfo);
// sendgrid details //
require("dotenv").config();
const sgMail = require("@sendgrid/mail");
const apikey = process.env.SENDGRID_API_KEY;
sgMail.setApiKey(apikey);
const msg = {
to: emailInfo,
from: "email",
subject: "Sending with Twilio SendGrid is Fun",
text: "and easy to do anywhere, even with Node.js",
html: "<strong>and easy to do anywhere, even with Node.js</strong>",
};
// email sending logic //
//ES8
(async () => {
try {
await sgMail.send(msg);
} catch (error) {
console.error(error);
if (error.response) {
console.error(error.response.body);
}
}
})();
});
app.listen(port, hostname, () => {
console.log(`Server running at http://${hostname}:${port}/`);
});
客戶端反應組件
import "../StyleComponents/CreateEvent.css";
import { useState } from 'react';
import { db } from '../firebase';
import { uid } from "uid";
import { set, ref } from "firebase/database";
import Header from "./Header";
import { useNavigate } from 'react-router-dom';
import { getStorage, ref as sref, uploadBytes } from "firebase/storage";
import PlacesAutocomplete from 'react-places-autocomplete';
import { geocodeByAddress, getLatLng } from 'react-places-autocomplete';
import axios from 'axios';
function CreateEvent() {
// store user inputs in state //
const [titleUserInput, setTitleUserInput] = useState('');
const [dateUserInput, setDateUserInput] = useState('');
const [timeUserInput, setTimeUserInput] = useState('');
const [address, setAddress] = useState('');
const [setCoordinates] = useState({
lat: null,
lng: null,
})
const [headerUserInput, setHeaderUserInput] = useState('');
const [detailsUserInput, setDetailsUserInput] = useState('');
const [lengthUserInput, setLengthUserInput] = useState('');
const [emailUserInput, setEmailUserInput] = useState('');
const [userSubmit, setUserSubmit] = useState('');
const [error, setError] = useState(false);
// Create a root reference for storing event photos //
const storage = getStorage();
// handle changing user input data //
const handleTitleChange = (e) => {
setTitleUserInput(e.target.value);
}
const handleDateChange = (e) => {
setDateUserInput(e.target.value);
}
const handleTimeChange = (e) => {
setTimeUserInput(e.target.value);
}
const handleSelect = async (value) => {
const results = await geocodeByAddress(value);
const latLng = await getLatLng(results[0]);
setAddress(value);
setCoordinates(latLng);
}
const handleDetailsChange = (e) => {
setDetailsUserInput(e.target.value);
}
const handleLengthChange = (e) => {
setLengthUserInput(e.target.value);
}
const handleHeaderChange = (e) => {
// Create a root reference for storing event photos //
setHeaderUserInput(e.target.files[0]);
}
const handleEmailChange = (e) => {
setEmailUserInput(e.target.value);
}
const navigate = useNavigate();
// make call to the backend database to send email user input data //
const url = 'http://localhost:4000';
const getEmailInput = () => {
axios.post(url, {emailUserInput}).then((res) => {
console.log(res);
}).catch(console.log('error'));
}
// submit user data to database with unique ID for each event //
const writeToDataBase = () => {
let uuid = uid()
if (titleUserInput.length === 0 || dateUserInput.length === 0 || timeUserInput.length === 0 || address.length === 0 || emailUserInput.length === 0) {
setError(true);
}
if (titleUserInput && dateUserInput && timeUserInput && address && emailUserInput) {
const storageRef = sref(storage, uuid);
set(ref(db, `/${uuid}`), {
EventPhoto: headerUserInput,
EventTitle: titleUserInput,
EventDate: dateUserInput,
EventTime: timeUserInput,
EventLength: lengthUserInput,
EventLocation: address,
EventDetails: detailsUserInput,
});
getEmailInput('');
setUserSubmit('');
uploadBytes(storageRef, headerUserInput).then(() => {
navigate(`/EventCreated/${uuid}`);
});
}
}
return (
<>
< Header />
<div className="event-creation-container">
<h1>Create a New Event</h1>
<form>
<div className="event-name-container event-input">
<label for="eventTitle">Name of Event<span>*</span></label>
<input type="text" id="EventTitle" value={titleUserInput} onChange={handleTitleChange} />
{error && titleUserInput === '' ?
<label id="form-validation-label">Event name must be filled</label> : ""}
</div>
<div className="date-time-length">
<div className="date-input-container event-input">
<label for="Date">Date<span>*</span></label>
<input type="date" id="EventDate" value={dateUserInput} onChange={handleDateChange} />
{error && dateUserInput === '' ? <label id="form-validation-label">Event date must be filled</label>: ""}
</div>
<div className="time-input-container event-input">
<label for="Time">Time<span>*</span></label>
<input id="EventTime" type="time" name="time" timezone="timezone" value={timeUserInput} onChange={handleTimeChange} />
</div>
{error && timeUserInput === '' ? <label id="form-validation-label">Event time must be filled</label> : ""}
<div className="length-input-container event-input">
<label for="Length">Length</label>
<input id="EventLength" type="text" value={lengthUserInput} onChange={handleLengthChange} />
</div>
</div>
<div className="location-input-container event-input">
<label for="Location">Location<span>*</span></label>
<PlacesAutocomplete onChange={setAddress} value={address} onSelect={handleSelect}
>
{({ getInputProps, suggestions, getSuggestionItemProps, loading }) => (
<div>
<input id="EventLocation" {...getInputProps()} />
<div className="location-suggestions">
{loading ? <div>...loading</div> : null}
{suggestions.map((suggestion) => {
const style = {
backgroundColor: suggestion.active ? "#41b6e6" : "#fff"
};
return <div {...getSuggestionItemProps(suggestion, { style })}>{suggestion.description}</div>
})}
</div>
</div>
)}
</PlacesAutocomplete>
</div>
{error && address ==='' ? <label id="form-validation-label">Event location must be filled</label> : ""}
<div className="details-input-container event-input">
<label for="Event_Details">Event Details</label>
<textarea type="text" id="EventDetails" value={detailsUserInput} onChange={handleDetailsChange} />
</div>
<div className="header-input-container event-input">
<div className="upload-image-flex-container">
<label for="header_image">Upload Header Image (optional)</label>
<input className="upload-input" type="file" id="
EventImage" name="filename" accept="image/png, image/jpeg" onChange={handleHeaderChange} />
</div>
</div>
<div className="orangizer-email-container">
<label for="organizer-email">Organizer's Email<span>*</span></label>
<p>The event page link will be sent to your email</p>
<input id="EventEmail" type="email" name="email" value={emailUserInput} onChange={handleEmailChange} />
{error && emailUserInput === '' ? <label id="form-validation-label">Event organizer's email must be entered</label> : ""}
</div>
<div className="create-event-btn-container">
<button className="event-create-button" type="button" value={userSubmit} onClick={writeToDataBase}>Create Event</button>
</div>
</form>
</div>
</>
)}
export default CreateEvent;
我認為您可以通過同時使用來實現這一點。 使用npm
同時安裝
npm i concurrently
同時安裝后,您需要按照步驟操作,您的 cors 肯定會工作。 這是最新的方法。 檢查這個鏈接,因為你已經同時正確地實現了這個 npm
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