File Coverage

blib/lib/Text/Diff/HTML.pm

Criterion	Covered	Total	%
statement	40	40	100.0
branch	6	8	75.0
condition			n/a
subroutine	12	12	100.0
pod	0	5	0.0
total	58	65	89.2

package Text::Diff::HTML;

use strict;
use vars qw(@ISA $VERSION);
use HTML::Entities;
use Text::Diff (); # Just to be safe.

$VERSION = '0.08';
@ISA = qw(Text::Diff::Unified);

sub file_header {
    return ''
           . encode_entities(shift->SUPER::file_header(@_))
           . '';
}

sub hunk_header {
    return ''
           . encode_entities(shift->SUPER::hunk_header(@_))
           . '';
}

sub hunk_footer {
    return ''
           . encode_entities(shift->SUPER::hunk_footer(@_))
           . '';
}

sub file_footer {
    return ''
           . encode_entities(shift->SUPER::file_footer(@_))
           . '';
}

# Each of the items in $seqs is an array reference. The first one has the
# contents of the first file and the second has the contents of the second
# file, all broken into hunks. $ops is an array reference of array references,
# one corresponding to each of the hunks in the sequences.
#
# The contents of each op in $ops tell us what to do with each hunk. Each op
# can have up to four items:
#
# 0: The index of the relevant hunk in the first file sequence.
# 1: The index of the relevant hunk in the second file sequence.
# 2: The opcode for the hunk, either '+', '-', or ' '.
# 3: A flag; not sure what this is, doesn't seem to apply to unified diffs.
#
# So what we do is figure out which op we have and output the relevant span
# element if it is different from the last op. Then we select the hunk from
# second sequence (SEQ_B_IDX) if it's '+' and the first sequence (SEQ_A_IDX)
# otherwise, and then output the opcode and the hunk.

use constant OPCODE    => 2; # "-", " ", "+"
use constant SEQ_A_IDX => 0;
use constant SEQ_B_IDX => 1;

my %code_map = (
    '+' => [ 'ins'              => 'ins' ],
    '-' => [ 'del'              => 'del' ],
    ' ' => [ 'span class="ctx"' => 'span' ]
);

sub hunk {
    shift;
    my $seqs = [ shift, shift ];
    my $ops  = shift;
    return unless @$ops;

    # Start the span element for the first opcode.
    my $last = $ops->[0][ OPCODE ];
    my $hunk = qq{<$code_map{ $last }->[0]>};

    # Output each line of the hunk.
    while (my $op = shift @$ops) {
        my $opcode = $op->[OPCODE];
        my $elem   = $code_map{ $opcode } or next;

        # Close the last span and start a new one for a new opcode.
        if ($opcode ne $last) {
            $hunk .= "[1]><$elem->[0]>";
            $last  = $opcode;
        }

        # Output the appropriate line.
        my $idx = $opcode ne '+' ? SEQ_A_IDX : SEQ_B_IDX;
        $hunk  .= encode_entities("$opcode $seqs->[$idx][$op->[$idx]]");
    }

    return $hunk . "[1]>";
}

1;
__END__