consumers.py

import json
import traceback
from channels.consumer import AsyncConsumer
from asgiref.sync import sync_to_async
from channels.exceptions import StopConsumer
from iotsite.models import Device
from random import randint
from time import sleep

"""
   Upload Channel
   Used by clients to update sensor data
"""
class UploadConsumer(AsyncConsumer):

    """
        Method called when websocket connects
    """
    async def websocket_connect(self,event):
        print("connected ", event)
        data = {
            "type": "websocket.accept",
            "text": "successfully connected client"
        }

        #sleep(1)
        try:
            await self.send(data)
            print("sent data")
        except Exception as e:
            print("didnt send data " + str(e))

    """
        Update sensor data
    """
    @sync_to_async
    def saveToObject(self, val_list):
        device = Device.objects.get(pk=val_list[0])
        device.machine.sensor_data_one = float(val_list[1])
        device.machine.sensor_data_one = float(val_list[2])
        device.machine.save()
        device.save()

    """
        Method called when server receives messsage from websocket
    """
    async def websocket_receive(self,event):
        print("received ", event)
        val_list = event['text'].split(",")

        sleep(1)
        print(val_list)
        await self.saveToObject(val_list)
        data = {
            "type": "websocket.accept",
            "text": "successfully added sensor data"
        }

        try:
            await self.send(data) #error here
            print("sent the data from recieved")
            sleep(1)
        except Exception as e:
            print("didnt send the data " + str(e))
            #print(traceback.format_exc())

    """
        Method called when websocket disconnected
    """
    async def websocket_disconnect(self, event):
        print("disconnected " + str(event) + "\n\n")


"""
    Working Example of Device Channel
    Clients can get device data thourgh this Channel
"""
class DeviceConsumer(AsyncConsumer):

    """
        Method called when websocket connects
    """
    async def websocket_connect(self,event):
        print("connected ", event)
        data = {
            "type": "websocket.accept",
        }
        await self.send(data)

    """
        Helper method to get Device data
    """
    @sync_to_async
    def getDeviceData(self, dev_id):
        dev = Device.objects.get(pk=dev_id)
        self.sensor_data = dev.machine.sensor_data_one

    """
        Method called when server receives messsage from websocket
        Sends back current sensor data
    """
    async def websocket_receive(self,event):
        print("received ", event)
        await self.getDeviceData(event['text'])

        data = {
            "type": "websocket.send",
            "text": str(self.sensor_data)
        }

        await self.send(data)

    """
        Method called when websocket disconnected
    """
    async def websocket_disconnect(self, event):
        print("disconnected", event)