Async WebSockets

[oliviermilla]

• Julia 1.8.2
• HTTP.jl 1.5.1
• MbedTLS.jl 1.1.7

Hello everyone,

I am building a package to connect to a websocket service.

Here is my understanding of the WebSockets API, the handler function is what the end user would pass to get callbacks.

function open(handler::Function)
    WebSockets.open(WEBSOCKETS_URL) do ws
        global webSocket[] = ws

        while true
            response = receive(ws)
            handler(JSON3.read(response, Response))
        end
    end
end

function close()
    WebSockets.close(webSocket[])
end

the while true feels really bad I have to say. Isn't there an async API to provide HTTP.WebSockets with callbacks directly?

Love your feedback, just starting out in julia.
Best!

[quinnj]

I'd recommend taking a look at the WebSockets documentation; particularly, we recommend this following pattern:

WebSockets.open(url) do ws
    for msg in ws
        # do cool stuff with msg
    end
end

For async, you can just wrap that block with the @async macro and store the task to inspect later if needed:

websocket_client_task = @async WebSockets.open(url) do ws
    for msg in ws
        # do cool stuff with msg
    end
end