Emit websocket message from a view
THIS IS VERY VERY SIMPLE DEMO EXAMPLE
In the below example, on every 2 seconds, the server send message to the client with updated count. First parameter of emit function tells which function to call on client side.
app.py
from flask import Flask, render_templatefrom flask_socketio import SocketIO, emitapp = Flask(__name__)app.config['SECRET_KEY'] = 'secret!'socketio = SocketIO(app)thread = Nonedef background_thread(): count = 0 while True: socketio.sleep(2) count += 1 socketio.emit('my_response', {'data': 'Message from server', 'count': count}, namespace='/test')@app.route('/')def index(): return render_template('index.html')@socketio.on('connect', namespace='/test')def test_connect(): global thread if thread is None: thread = socketio.start_background_task(target=background_thread) emit('my_response', {'data': 'Connected', 'count': 0})if __name__ == '__main__': socketio.run(app, debug=True, host='0.0.0.0', port=5050)On your client side you will have to use this. In this example I have included CDN. Similarly for demo purpose I have used jquery.
templates/index.html
<!DOCTYPE HTML><html><head> <title>Flask-SocketIO Test</title> <script type="text/javascript" src="//code.jquery.com/jquery-1.4.2.min.js"></script> <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/socket.io/1.3.5/socket.io.min.js"></script> <script type="text/javascript" charset="utf-8"> $(document).ready(function() { namespace = '/test'; var socket = io.connect(location.protocol + '//' + document.domain + ':' + location.port + namespace); // This will be called by server. // Anonymous function will be executed and span with id "view" will be updated socket.on('my_response', function(msg) { $('span#view').text(msg.count); }); }); </script></head><body> <h1>Flask-SocketIO Simple Example</h1> <p>Counter at server: <span id="view"></span></p></a></body></html>When you run this using python app.py, and visit http://127.0.0.1:5050, then you should see the sockets in action.
A working version of the demo is available here