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	12	12	100.0
pod	1	1	100.0
total	108	112	96.4

package Log::Contextual::WarnLogger;
use strict;
use warnings;

our $VERSION = '0.009001';

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__