On 9/2/20 2:36 PM, Sven Van Caekenberghe wrote:
Hi Jimmie,
On 2 Sep 2020, at 20:29, Jimmie Houchin <jlhouchin@gmail.com> wrote:
Before I get to my problem. I want to thank Sven for the huge effort that had to be made to provide all of the Zinc networking tools. Thank you. Thanks, you're welcome.
I am using ZnClient in an app. It is working fine. But I do not want any UI Notifications. This will eventually be headless on a server. But right now in development when the internet goes out I get a pop up from NameLookupFailure which offers me the options of "Give Up" or "Retry".
I need to suppress this popup. I already have Error handling code which will catch NameLookupFailure among many other network based errors. I know this is confusing, but this is not a problem. You can simply catch the NameLookupFailure and this will work as expected. The problem is the custom/overwritten NameLookupFailure>>#defaultAction which is doing UI stuff (although this gets handled differently in a headless image as well). IMHO this should be removed.
ZnClientTest>>#testIfFailNonExistingHost is an example that does more or less what you want.
Yes. In the current stack trace in the debugger it never reaches my Error handling and hits the #defaultAction method. Thanks. That puts me on the path I want to go. I probably need to learn to read the tests for or as documentation for code. I am not currently in that habit.
Also, is there a better way to check if the network is up other than simply making a request and either getting a successful response or an Error? This is not such an easy problem to solve. Doing something simple, like accessing a known host, is one way (but never 100% since that host might be down on itself).
There is also the problem of timeouts (i.e. very slow networks).
One of my experimental projects, https://github.com/svenvc/NeoDNS, does contains something called NeoNetworkState that tests internet connectivity by doing a DNS call. But this probably goes to far.
HTH,
Helps tremendously. Currently when I get a network error, I have a loop which polls the least resource consuming URL on the server that I need to access. I exit the loop upon a successful response and continue with my app's main loop. I figure that lets me know that networking is back up and the server I need is responding. Covers all my bases. I just wanted to know if I was overlooking something that all you smart people who spend way more time than I do on this stuff had a solution. I couldn't think of an easy generic solution that could be created. Again thanks.
Sven
Thanks for any help.
Jimmie