package Data::Printer::Filter::Digest;
use strict;
use warnings;
use Data::Printer::Filter;
use Term::ANSIColor;
foreach my $digest ( qw(Digest::MD2 Digest::MD4) ) {
filter $digest => \&_print_digest;
}
filter '-class', sub {
my ($obj, $p) = @_;
return unless $obj->isa( 'Digest::base' );
return _print_digest( $obj, $p );
};
sub _print_digest {
my ($obj, $p) = @_;
my $digest = $obj->clone->hexdigest;
my $str = $digest;
my $ref = ref $obj;
if ( $p->{digest}{show_class_name} ) {
$str .= " ($ref)";
}
unless ( exists $p->{digest}{show_reset}
and !$p->{digest}{show_reset}
) {
if ($digest eq $ref->new->hexdigest) {
$str .= ' [reset]';
}
}
my $color = $p->{color}{digest};
$color = 'bright_green' unless defined $color;
return colored( $str, $color );
}
1;
__END__
=head1 NAME
Data::Printer::Filter::Digest - pretty-printing MD5, SHA and friends
=head1 SYNOPSIS
In your program:
use Data::Printer filters => {
-external => [ 'Digest' ],
};
or, in your C<.dataprinter> file:
{
filters => {
-external => [ 'Digest' ],
},
};
You can also setup color and display details:
use Data::Printer
filters => {
-external => [ 'Digest' ],
},
color => {
digest => 'bright_green',
}
digest => {
show_class_name => 0, # default.
show_reset => 1, # default.
},
};
=head1 DESCRIPTION
This is a filter plugin for L<Data::Printer>. It filters through
several digest classes and displays their current value in
hexadecimal format as a string.
=head2 Parsed Modules
=over 4
=item * L<Digest::Adler32>
=item * L<Digest::MD2>
=item * L<Digest::MD4>
=item * L<Digest::MD5>
=item * L<Digest::SHA>
=item * L<Digest::SHA1>
=item * L<Digest::Whirlpool>
=back
If you have any suggestions for more modules or better output,
please let us know.
=head2 Extra Options
Aside from the display color, there are a few other options to
be customized via the C<digest> option key:
=head3 show_class_name
Set this to true to display the class name right next to the
hexadecimal digest. Default is 0 (false).
=head3 show_reset
If set to true (the default), the filter will add a C<[reset]>
tag after dumping an empty digest object. See the rationale below.
=head2 Note on dumping Digest::* objects
The digest operation is effectively a destructive, read-once operation. Once it has been performed, most Digest::* objects are automatically reset and can be used to calculate another digest value.
This behaviour - or, rather, forgetting about this behaviour - is
a common source of issues when working with Digests.
This Data::Printer filter will B<not> destroy your object. Instead, we work on a cloned version to display the hexdigest, leaving your
original object untouched.
As another debugging convenience for developers, since the empty
object will produce a digest even after being used, this filter
adds by default a C<[reset]> tag to indicate that the object is
empty, in a 'reset' state - i.e. its hexdigest is the same as
the hexdigest of a new, empty object of that same class.
=head1 SEE ALSO
L<Data::Printer>