Wikipedia:Reference desk/Archives/Computing/2020 September 25

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September 25

Further WebSocket question

As I mentioned before, at work I am developing a system which consists of two separate applications, a Windows .NET C# desktop application and a web application, of which the front end is written in HTML and JavaScript, the back end in .NET C#. The web application's front end and the desktop application communicated with each other via WebSockets.

There is a web page which opens a WebSocket connection to the desktop application on load, and then listens on messages sent by the desktop application. This part was easy enough.

But the problem is, the web application should close the WebSocket connection when the user navigates away from the page, explicitly letting the desktop application know about this, so it can set its state properly. I have tried various ways to do this, but whatever way I try, the desktop application either ignores this entirely or fails to read the close request because the connection is closed as soon as the request is sent. The best I can imagine would be that the desktop application catches failure to read the connection and then sets its state properly. But I'd rather handle this more gracefully. Is this possible? JIP | Talk 01:25, 25 September 2020 (UTC)

Have you tried a web search? A lot of stuff like this is already answered on other websites... Did you send "Connection: keep-alive"? Otherwise the client or server will automatically close the connection Wubbalubbadubdub42 (talk) 00:11, 26 September 2020 (UTC)

JIP, all browsers automatically close the socket connections when a user navigates away. There should be an "on close" event for the connection which you should handle in your server code, then you can dispose of the socket correctly from there. You handle the connection close, sending a close message is practically impossible. Ed talk! 13:23, 26 September 2020 (UTC)

The server side (which lives in the desktop application) accepts a TcpClient connection when the web browser connects to the WebSocket. This page explicitly says that TcpClient does not get notified when the client side disconnects. So there does not seem to be an "on close" event for TcpClient. Is there some other way? JIP | Talk 12:00, 27 September 2020 (UTC)

what is sticky black stuff on computer casing

what is sticky black stuff on computer casing — Preceding unsigned comment added by 220.255.238.193 (talk) 02:44, 25 September 2020 (UTC)

Unless you think the sticky stuff is software, this is not a question about computing, information technology, electronics, software, or hardware. Without more information it is impossible to answer the question. Normally, there is no sticky stuff on computer casings, nor should there be. Perhaps the case was stored under a roof sealed with tar paper, and it got so hot that the tar melted and some of it dripped on the casing. Or someone was careless when shining their shoes and left a dollop of black shoe creme on the casing. Or there was black isolation tape pasted over it and the sticky stuff remained when the tape was pulled off. Or the casing is made of an inferior-quality plastic and is weeping out the plasticizer. And so on.  --Lambiam 09:12, 25 September 2020 (UTC)

Inside you might find solder flux, heatsink compound or potting compound. But none of these should be leaking out. Perhaps there once was a sticker on the computer case that left the glue. Graeme Bartlett (talk) 11:51, 27 September 2020 (UTC)

Websites that haven't changed since 1990s

Approximately how many currently working websites haven't changed their design since the 1990s and early 2000s? Throughout my entire browsing I encountered only a few, less than 10 possibly, but still was positively surprised in a flashback. 212.180.235.46 (talk) 16:55, 25 September 2020 (UTC)

There are (at least) 23 Ancient Web Sites That Are Still Alive. 2606:A000:1126:28D:ADC6:7A08:1D3C:354B (talk) 03:45, 27 September 2020 (UTC)

Well, the last major redesign to my personal site was shortly after I switched from Blogger to Wordpress in 2004. —Tamfang (talk) 01:35, 30 September 2020 (UTC)

Slashdot changed to a completely new design that everyone hated, so they were forced to switch back to the old design. Its front page now resembles the 1990's version again, though there have been various modifications over the years, particularly on the interior (comment thread) pages. Craigslist has also gone to a fair amount of trouble to keep its traditional look. 2601:648:8202:96B0:0:0:0:DDAF (talk) 20:23, 30 September 2020 (UTC)