package EBook::Ishmael::EBook::XHTML;
use 5.016;
our $VERSION = '1.06';
use strict;
use warnings;
use parent 'EBook::Ishmael::EBook::HTML';
my $XHTML_NS = 'http://www.w3.org/1999/xhtml';
sub heuristic {
        my $class = shift;
        my $file  = shift;
        my $fh    = shift;
        return 1 if $file =~ /\.xhtml?$/;
        return 0 unless -T $fh;
        read $fh, my ($head), 1024;
        return 0 unless $head =~ /<[^<>]+xmlns\s*=\s*"\Q$XHTML_NS\E"[^<>]*>/;
        return $head =~ /<\s*html[^<>]+>/;
}
1;