I'm trying to build a Flask server in Python that uses socket.io. As I have never used socket.io before I used the code from Miguel Grinberg to make a simple website to test if I can get it working. When I navigate to the website and then check the server-console I see requests coming in to "/socket.io/?EIO=4&transport=polling&t=<some code>" that are responded to with status code 200.
However, in my browser (Chrome) the console shows an error: "Uncaught DOMException: Failed to read the 'responseText' property from 'XMLHttpRequest': The value is only accessible if the object's 'responseType' is '' or 'text' (was 'arraybuffer')." screenshot
It seems to me like when calling io.connect in my javascript a request is made to the server but somehow the response or the processing of it fails which results in a failed connection.
Does anyone have any idea for why that happens and how to fix it?
My server side code is
from flask import Flask, render_template from flask_socketio import SocketIO, emit app = Flask(__name__) app.config['SECRET_KEY'] = 'secret!' socketio = SocketIO(app) @app.route('/') def index(): return render_template('index.html') @socketio.on('my event', namespace='/test') def test_message(message): emit('my response', {'data': message['data']}) @socketio.on('connect', namespace='/test') def test_connect(): emit('my response', {'data': 'Connected'}) @socketio.on('disconnect', namespace='/test') def test_disconnect(): print('Client disconnected') if __name__ == '__main__': socketio.run(app) The Javascript running on the client side is
$(document).ready(function(){ var socket = io.connect('http://' + document.domain + ':' + location.port + '/test'); socket.on('my response', function(msg) { $('#log').append('<p>Received: ' + msg.data + '</p>'); }); $('form#emit').submit(function(event) { socket.emit('my event', {data: $('#emit_data').val()}); return false; }); }); 
