[Django]-Getting Django channel access in Celery task

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13👍

✅

@normic: Yes, I was struggling with the later addition of channel layers into my projects:

@Ken4scholars: Many thanks for the links. These prompted me to find what I was looking for.

For anyone else struggling:

my tasks.py:

from __future__ import absolute_import, unicode_literals
from celery import shared_task
import time

from channels.layers import get_channel_layer
from asgiref.sync import async_to_sync


@shared_task
def add(x, y):
    return x + y


@shared_task
def go_to_sleep_and_add(x,y):
    time.sleep(10)
    result = int(x)+int(y)
    channel_layer = get_channel_layer()
    async_to_sync(channel_layer.group_send)(
        'task_group_a',
        {
                'type': 'task_message',
                'message': result
        }
    )
    return result


@shared_task
def mul(x, y):
    return x * y


@shared_task
def xsum(numbers):
    return sum(numbers)

my consumers.py:

from channels.generic.websocket import WebsocketConsumer
import json
from access.tasks import go_to_sleep_and_add    
from channels.layers import get_channel_layer
from asgiref.sync import async_to_sync

class AccessConsumer(WebsocketConsumer):
    def connect(self):
        self.accept()
        self.room_group_name = "task_group_a"

        # Join room group
        async_to_sync(self.channel_layer.group_add)(
            self.room_group_name,
            self.channel_name
        )

    def disconnect(self, close_code):
        async_to_sync(self.channel_layer.group_discard)(
            self.room_group_name,
            self.channel_name
        )

    def receive(self, text_data):
        text_data_json = json.loads(text_data)
        num1 = text_data_json['message']['1']
        num2 = text_data_json['message']['2']
        if num1.isnumeric() and  num2.isnumeric()== True:

            go_to_sleep_and_add.delay(num1,num2)
            self.send(text_data=json.dumps({
                'message': 'We are dealing with your request'
            }))

        else:
            self.send(text_data=json.dumps({
                'message': 'Give me numbers'
            }))

    # Receive message from room group  
    def task_message(self, event):
        message = event['message']

        # Send message to WebSocket
        self.send(text_data=json.dumps({
            'message': message
        }))

my html page in Django/templates:

<!-- access/templates/access/room.html -->
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8"/>
    <title>Access Room</title>
</head>
<body>
    <textarea id="access-log" cols="50" rows="5">Results &#13;&#10;</textarea><br/>
    Number 1:<input id="access-message-input" type="text" size="20"/><br/>
    Number 2:<input id="access-message-input2" type="text" size="20"/><br/>
    <input id="access-message-submit" type="button" value="Send"/>
</body>
<script>
    var roomName = {{ room_name_json }};
    var accessSocket = new WebSocket(
        'ws://' + window.location.host +
        '/ws/access/' + roomName + '/');
    accessSocket.onmessage = function(e) {
        var data = JSON.parse(e.data);
        var message = data['message'];
        document.querySelector('#access-log').value += (message + '\n');
    };

    accessSocket.onclose = function(e) {
        console.error('Access socket closed unexpectedly');
    };

    document.querySelector('#access-message-submit').onclick = function(e) {
        var messageInputDom = document.querySelector('#access-message-input');
        var messageInputDom2 = document.querySelector('#access-message-input2');
        COMPLETE = { '1': messageInputDom.value, '2': messageInputDom2.value}
        accessSocket.send(JSON.stringify({
            'message': COMPLETE
        }));

        messageInputDom.value = '';
        messageInputDom2.value = '';

    };

</script>

</html>
👤user4292309

1👍

I had the same problem but mine got resolved after using channels-redis

At first I used InMemoryChannelLayer and couldn’t get past through it but after using channels_redis.pubsub.RedisPubSubChannelLayer everything works as a charm

👤Hossein Gholami

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