Question: Detect Window Close

[MichaelMay81]

A part of my app should update continuously.

let delayedDownload (delayInMin:int) = async {
    do! delayInMin * 60 |> Task.Delay |> Async.AwaitTask
    return! remote.getDownloadLinks ()
}

I put this in a Cmd and when I get the 'msg I schedule it again.
But on closing the page this continuous to run.

I need a way to detect, that the window has been closed, to stop that scheduling.

Adding a component and dispatching a 'msg on Dispose seems to work. Although it takes 3 minutes from closing the window until the Dispose and I haven´t figured out how to give the component the dispatch function.

Is there a recommended way to do this?

[MichaelMay81]

Different approach:

let timer onTick =
        let start dispatch =
            let timer = new Timer(10000.)
            timer.add_Elapsed(fun _ e ->
                printfn $"Timer {e.SignalTime}"
                dispatch onTick)
            timer.Start()
            
            { new System.IDisposable with
                member _.Dispose() =
                    printfn $"Timer disposed"
                    timer.Stop ()
                    timer.Dispose () }
        start

    let subscribe model =
        [ ["timer"], timer Done ]

...
|> Program.withSubscription subscribe
...

Finally the dispatch works (couldn't get that running with a Component), but it still doesn't stop (gets disposed) when the Window closes.

[MichaelMay81]

I couldn't get it to run. But I found a better way for my specific problem (Update Links when link is actually clicked).
I would still be interested if anyone knows a solution to this, though....