socket example app2 (snippet)

Python socket example 'app2'

Functions in program:

def api(message):
def index():

Modules used in program:

import json

python app2

Python socket example: app2

from flask.ext.socketio import SocketIO, emit
from flask import Flask, render_template_string
import json

app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret!'
socketio = SocketIO(app)
app.config['DEBUG'] = True

template = """
<html><body><table>
{% for key, value in appliances.iteritems() %}
<tr><td>{{ key }}</td><td>{{ value }}</td></tr>
{% endfor %}
</table>
<form>
<input type="text" id="device">
<input type="number" id="capacity" step="1" pattern="\d*">
<input type="submit">
</form>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.16/socket.io.min.js"></script>
<script type="text/javascript">
$(function() {
  var socket = io.connect('http://' + document.domain + ':' + location.port);
  socket.on('update', function(message) {
    var data = JSON.parse(message);
    $("table").append("<tr><td>" + data.device + "</td><td>" + data.capacity + "</td></tr>");
  });

  $("form").submit(function(event) {
    var data = {"device" : $("#device").val(), "capacity" : parseInt($("#capacity").val(), 10)};
    socket.emit('update', JSON.stringify(data));
    event.preventDefault();
  });
});
</script>
</body></html>
"""

@app.route('/')
def index():
    with open('appliances.json', 'r') as json_file:
        appliances = json.load(json_file)
    return render_template_string(template, appliances=appliances)

@socketio.on('update')
def api(message):
    emit('update', message, broadcast=True)
    data = json.loads(message)
    with open('appliances.json', 'r') as json_file:
        appliances = json.load(json_file)
    appliances[data['device']] = data['capacity']
    with open('appliances.json', 'w') as json_file:
        json.dump(appliances, json_file)

if __name__ == '__main__':
    socketio.run(app)

Python links

Learn Python: https://pythonbasics.org/
Python Tutorial: https://pythonprogramminglanguage.com