react frontend connecting to flask backend Howto

Question

I have a ReactJS front end and a flask backend and I am having difficulties making both talk to each other, particular sending form variables from the frontend to Flask.

Answer 1

I have tweaked your code a little bit. Changes I have made:

• added the backend path http://localhost:5000/result in frontend as form action path.
• used request.args.get method to grab the submitted value.

The frontend is running on port 3000 and the backend is running on port 5000; both in localhost.

Frontend code:

import ReactDOM from 'react-dom';
import React, {Component} from 'react';
class Form1 extends Component{
    render(){
        return (
            <div class="form">
                <form action="http://localhost:5000/result" method="get">
                    Place: <input type="text" name="place"/>
                    <input type="submit" value="Submit"/>
                </form>
            </div>
        );
    }
}
ReactDOM.render(
    <Form1/>,
    document.getElementById('root')
);

Backend Code:

from flask import Flask, request

app = Flask(__name__)

@app.route('/result', methods = ['GET', 'POST'])
def result():
    if request.method == 'GET':
        place = request.args.get('place', None)
        if place:
            return place
        return "No place information is given"

if __name__ == '__main__':
    app.run(debug = True)

Here is the screenshot of running program:

Reference:

Flask documentation: The request object