File Coverage

blib/lib/Log/Contextual/WarnLogger.pm

Criterion	Covered	Total	%
statement	62	62	100.0
branch	23	26	88.4
condition	10	11	90.9
subroutine	16	16	100.0
pod	1	1	100.0
total	112	116	96.5

package Log::Contextual::WarnLogger;
$Log::Contextual::WarnLogger::VERSION = '0.008000';
# ABSTRACT: logger for libraries using Log::Contextual

use strict;
use warnings;

use Carp 'croak';

my @default_levels = qw( trace debug info warn error fatal );

# generate subs to handle the default levels
# anything else will have to be handled by AUTOLOAD at runtime
{
   for my $level (@default_levels) {

      no strict 'refs';

      my $is_name = "is_$level";
      *{$level} = sub {
         my $self = shift;

         $self->_log($level, @_)
           if $self->$is_name;
      };

      *{$is_name} = sub {
         my $self = shift;
         return 1 if $ENV{$self->{env_prefix} . '_' . uc $level};
         my $upto = $ENV{$self->{env_prefix} . '_UPTO'};
         return unless $upto;
         $upto = lc $upto;

         return $self->{level_num}{$level} >= $self->{level_num}{$upto};
      };
   }
}

our $AUTOLOAD;

sub AUTOLOAD {
   my $self = $_[0];

   (my $name = our $AUTOLOAD) =~ s/.*:://;
   return if $name eq 'DESTROY';

   # extract the log level from the sub name
   my ($is, $level) = $name =~ m/^(is_)?(.+)$/;
   my $is_name = "is_$level";

   no strict 'refs';
   *{$level} = sub {
      my $self = shift;

      $self->_log($level, @_)
        if $self->$is_name;
   };

   *{$is_name} = sub {
      my $self = shift;

      my $prefix_field = $self->{env_prefix} . '_' . uc $level;
      return 1 if $ENV{$prefix_field};

      # don't log if the variable specifically says not to
      return 0 if defined $ENV{$prefix_field} and not $ENV{$prefix_field};

      my $upto_field = $self->{env_prefix} . '_UPTO';
      my $upto       = $ENV{$upto_field};

      if ($upto) {
         $upto = lc $upto;

         croak "Unrecognized log level '$upto' in \$ENV{$upto_field}"
           if not defined $self->{level_num}{$upto};

         return $self->{level_num}{$level} >= $self->{level_num}{$upto};
      }

      # if we don't recognize this level and nothing says otherwise, log!
      return 1 if not $self->{custom_levels};
   };
   goto &$AUTOLOAD;
}

sub new {
   my ($class, $args) = @_;

   my $levels = $args->{levels};
   croak 'invalid levels specification: must be non-empty arrayref'
     if defined $levels and (ref $levels ne 'ARRAY' or !@$levels);

   my $custom_levels = defined $levels;
   $levels ||= [@default_levels];

   my %level_num;
   @level_num{@$levels} = (0 .. $#{$levels});

   my $self = bless {
      levels        => $levels,
      level_num     => \%level_num,
      custom_levels => $custom_levels,
   }, $class;

   $self->{env_prefix} = $args->{env_prefix}
     or die 'no env_prefix passed to Log::Contextual::WarnLogger->new';
   return $self;
}

sub _log {
   my $self    = shift;
   my $level   = shift;
   my $message = join("\n", @_);
   $message .= "\n" unless $message =~ /\n$/;
   warn "[$level] $message";
}

1;

__END__