Control warnings for each module by creating new warning categories

bliako has asked for the wisdom of the Perl Monks concerning the following question:

For a recent post (Solve IO::Pty warning issues from Net::OpenSSH) I tried to create a new category for warnings for a module and then disable it but it failed (perl 5.34.0) when I used it as *I expected*:

{
package XXX;
use strict;
# register a new warnings category with this package name
use warnings::register;
sub expected {
        warn "ajajaj";
}
sub correct {
  if( warnings::enabled() ){
      warn "ajajaj";
  } else { print "not warning!\n" }
}
1;
}

# it's already loaded...
#use XXX;
no warnings('XXX');

# this says 'no' (as expected)
print "enabled: ".(warnings::enabled('XXX')?"yes":"no")."\n";

XXX::expected(); # this still warns

XXX::correct(); # this does not warn
[download]

Firstly, correct me if I am doing something wrong.

Secondly, am I expecting too much to just register a category within a module and then anyone from outside it, to enable or disable it? Why the check to warnings::enabled() in each and every warn() statement of that module. That makes refactoring to using warning categories very difficult.

Comment on Control warnings for each module by creating new warning categories Select or Download Code

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Re: Control warnings for each module by creating new warning categories by pryrt (Abbot) on Jun 24, 2024 at 13:28 UTC
change instances of `warn` to `warnings::warnif`, like `sub expected { warnings::warnif "ajajaj"; }` [download] When I make that change in your example, I get the output: `enabled: no not warning!` [download] To make this change globally, you'd just need to refactor via `s/(?!warnings::)\bwarn\b/warnings::warnif/g`	[reply] [d/l] [select]
Re: Control warnings for each module by creating new warning categories by LanX (Saint) on Jun 24, 2024 at 13:09 UTC
I didn't try your code, but from looking into https://perldoc.perl.org/warnings#Reporting-Warnings-from-a-Module I think your fears are justified. (Tho the code examples might need correction regarding the package name `abc::` ) But ... > That makes refactoring to using warning categories very difficult IMHO... You could locally (i.e. package wide) replace `warn` for your `XXX::` only and handle all the magic inside a single routine. Use `subs` for overriding built-ins. Cheers Rolf _{(addicted to the Perl Programming Language :) see Wikisyntax for the Monastery}	[reply] [d/l] [select]