Error with send_json Function in AsyncJsonWebsocketConsumer about channels HOT 6 CLOSED

Compare your class:

https://github.com/DevGauravJoshi/python_async/blob/eb0cfb1894fcaaa1aaeed245a032ff1c6ecd40c3/backend/chats/consumers.py#L180-L182

to the base class:

By overriding this method without using the async keyword, the await call at the error point is receiving a string, rather than a coroutine object. You want to pass UUIDEncoder, but you still need to declare the method async def.

from channels.

After examining the code within the parent class (AsyncJsonWebsocketConsumer), I noticed that the encoding process for the content using json.dumps(content) was utilizing the await keyword. However, I found that removing the await and simply using json.dumps resolved the error. This adjustment allowed the "welcome message" to be sent successfully to the client side without encountering any error.

from channels.

The encode_json method is unchanged since it was introduced:

de82aaa#diff-8adaf2e6e01ec2cc05dd10bfd212d6dddfadabe0ddc679b821e03024806647b7R254-R256

    @classmethod
     async def encode_json(cls, content):
         return json.dumps(content)

from channels.

encode_json is defined as an async function, but it uses json.dumps which is a synchronous function.

Error explanation:

When we call await self.encode_json(content), it treats the return value of json.dumps(content) as a coroutine, but since json.dumps returns a string synchronously, it raises the TypeError.

Here is the error message:

If I am misunderstanding something, please let me know.

from channels.

It looks like you've overridden a method maybe and forgotten an async.

Please post code rather than screenshots.

The async send_json method is covered by the test suite. If you could add a test demonstrating your issue, that would help to identify what you're seeing.

from channels.

chats/consumers.py

class ChatConsumer(AsyncJsonWebsocketConsumer):
    async def connect(self):
        # Accept the connection
        await self.accept()

        # Send a welcome message
        await self.send_json(
            {
                "type": "welcome_message",
                "message": "Welcome to the Websocket Connection",
            }
        )

The error traceback is as follows:

python3.12/site-packages/channels/generic/websocket.py", line 282, in send_json
    await super().send(text_data=await self.encode_json(content), close=close)
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: object str can't be used in 'await' expression

The full chats/consumers.py file can be found here: ChatConsumer file.

Here is a video demo of the error.

from channels.