socketio.py

from flask import request
from flask_login import current_user
from flask_socketio import join_room, leave_room
from .. import socketio
from ..decorators import socketio_login_required
from ..models import User


'''
' A list containing session ids of connected Socket.IO sessions, to keep track
' of all connected sessions, which can be used to determine the runtimes of
' associated background tasks.
'''
sessions = []


###############################################################################
# Socket.IO event handlers                                                    #
###############################################################################
@socketio.on('connect')
@socketio_login_required
def socketio_connect():
    '''
    ' The Socket.IO module creates a session id (sid) for each request.
    ' On connect the sid is saved in the connected sessions list.
    '''
    sessions.append(request.sid)


@socketio.on('disconnect')
def socketio_disconnect():
    '''
    ' On disconnect the session id gets removed from the connected sessions
    ' list.
    '''
    try:
        sessions.remove(request.sid)
    except ValueError:
        pass


@socketio.on('start_user_session')
@socketio_login_required
def socketio_start_user_session(user_id):
    user = User.query.get(user_id)
    if user is None:
        response = {'code': 404, 'msg': 'Not found'}
        socketio.emit('start_user_session', response, room=request.sid)
    elif not (user == current_user or current_user.is_administrator):
        response = {'code': 403, 'msg': 'Forbidden'}
        socketio.emit('start_user_session', response, room=request.sid)
    else:
        response = {'code': 200, 'msg': 'OK'}
        socketio.emit('start_user_session', response, room=request.sid)
        socketio.emit('user_{}_init'.format(user.id), user.to_dict(),
                      room=request.sid)
        room = 'user_{}'.format(user.id)
        join_room(room)


@socketio.on('stop_user_session')
@socketio_login_required
def socketio_stop_user_session(user_id):
    user = User.query.get(user_id)
    if user is None:
        response = {'code': 404, 'msg': 'Not found'}
        socketio.emit('stop_user_session', response, room=request.sid)
    elif not (user == current_user or current_user.is_administrator):
        response = {'code': 403, 'msg': 'Forbidden'}
        socketio.emit('stop_user_session', response, room=request.sid)
    else:
        response = {'code': 200, 'msg': 'OK'}
        socketio.emit('stop_user_session', response, room=request.sid)
        room = 'user_{}'.format(user.id)
        leave_room(room)