Tl::MainLoop() catch errors

[Anonymous Monk]

Hi Monks,

I noticed that MainLoop() seems to catch errors before I do. For example if I execute a messed up DBI call or maybe call a object method that doesn't exist...

Does this make sense? Is there a way I can catch them first? (I need to handle the error gracefully ;-)

thanks for any suggestions!!!

[rjray]

(I assume you meant Tk::MainLoop.)

The Tk module has to necessarily catch fatal errors, as there is a lot of cleaning up to do in the graceful shutting down of a GUI. What you should do is wrap the potentially-problematic lines of code in eval {} blocks, then check for errors by examining $@.

--rjray

[Anonymous Monk]

Thanks!

I have a followup question...it seems I need to call die() to get the eval{} to catch the error...maybe it is DBI specific though...I guess I don't understand who is "raising" the error to eval {} me or some library code??? ($@ doesn't catch an error unless I call die() eventhough the library is printing error messages...)



eval {
  my $dbh = DBI->connect("bad stuff here")...|| die "dead";
}
if($@) {
print "ERROR"
}

[rjray]

Well, if the call to DBI->connect() doesn't cause a fatal error, can't you just examine the value of $dbh to see if there was an internal error that was by nature non-fatal? Of course, you probably don't want to be declaring $dbh to be a lexical within the scope of the eval {}... I would think you want the handle if the connect succeeds.

--rjray

[rinceWind]

If you set $DBI::RaiseError to 1, the exceptions are raised for you (i.e. DBI calls die).

[screamingeagle]

Could you please elaborate on what exactly you're trying to do ? your post is a bit vague And posting some code always helps :-)