Question

In a client application I have a DBIx::Class model ‘Todo’ that can be linked to a number of other models using a many-to-many relation.
I know, because of business logic, that 1 and only 1 foreign model is linked to it. I want to fetch that model in my query using:

my $objects = $c->model('DB')->resultset('Todo')->search($myFilter,{
    prefetch => \@relations # contains all possible relations
});

Like the documentation states DBIx::Class::ResultSource warns about this:

DBIx::Class::ResultSet::next(): Prefetching multiple has_many rels accountbalances_todos and accounts_todos at top level will explode the number of row objects retrievable via ->next or ->all. Use at your own risk. at /media/psf/projects/.../Controller/Todo.pm line 117

Can anyone tell me how to prevent this error without resorting to editing DBIx::Class::ResultSource itself? I see no other way of doing what I want and want to prevent the application dumping a lot of warnings in the log. I have tried fiddling with @CARP_NOT and $Carp::Internal, but cannot get Carp from skipping this warning (the documentation on this is sparse at best)

If anyone could help me that would be awesome, thanks

Answer 1

You could override the default handling of warning signals to catch and ignore this specific warning:

$SIG{__WARN__} = sub {
  my $warn_msg = $_[0];
  if ( $warn_msg =~ m/Prefetching multiple has_many rels accountbalances_todos/ ) {
    # do nothing
  } else {
    warn $warn_msg;
  }
};

or, if you prefer,

$SIG{__WARN__} = sub {
  warn $_[0] unless $_[0] =~ m/Prefetching multiple has_many rels accountbalances_todos/
};