HTML::Links::Localize - Convert HTML Files to be used on a hard disk

    use HTML::Links::Localize;

    my $converter = 
        HTML::Links::Localize->new(
            'base_dir' => "/var/www/html/shlomi/Perl/Newbies/lecture4/",
            'dest_dir' => "./dest"
        );

    $converter->process_file("mydir/myfile.html");

    $converter->process_dir_tree('only-newer' => 1);

    my $new_content = $converter->process_content(\$html_text);

package HTML::Links::Localize;

use strict;

use HTML::TokeParser;
use File::Find;
use File::Copy;

use vars qw($VERSION);

$VERSION = "0.2.6";

# Two utility functions
sub _is_older
{
    my $file1 = shift;
    my $file2 = shift;
    my @stat1 = stat($file1);
    my @stat2 = stat($file2);
    return ($stat1[9] <= $stat2[9]);
}

sub _is_newer
{
    my $file1 = shift;
    my $file2 = shift;
    return (! _is_older($file1, $file2));
}

sub new
{
    my $class = shift;
    my $self = {};
    bless $self, $class;

    $self->_init(@_);

    return $self;
}

sub _set_base_dir
{
    my $self = shift;

    my $base_dir = shift;

    $base_dir =~ s{/*$}{/};

    $self->{'base_dir'} = $base_dir;

    return 0;
}

sub _get_base_dir
{
    my $self = shift;

    return $self->{'base_dir'};
}

sub _set_dest_dir
{
    my $self = shift;

    my $dest_dir = shift;

    $self->{'dest_dir'} = $dest_dir;
    
    return 0;
}

sub _get_dest_dir
{
    my $self = shift;

    return $self->{'dest_dir'};
}

sub _init
{
    my $self = shift;

    my %args = @_;

    $self->_set_base_dir($args{'base_dir'} || ".");

    $self->_set_dest_dir($args{'dest_dir'} || "./dest");

    return 0;
}

sub process_content
{
    my $self = shift;

    my $file = shift;

    my $out_content = "";

    my $out = sub {
        $out_content .= join("", @_);
    };
   
    my $parser = HTML::TokeParser->new($file);
    while (my $token = $parser->get_token())
    {
        my $type = $token->[0];
        if ($type eq "E")
        {
            $out->($token->[2]);
        }
        elsif ($type eq "C")
        {
            $out->($token->[1]);
        }
        elsif ($type eq "T")
        {
            $out->($token->[1]);
        }
        elsif ($type eq "D")
        {
            $out->($token->[1]);
        }
        elsif ($type eq "PI")
        {
            $out->($token->[2]);
        }
        elsif ($type eq "S")
        {
            my $tag = $token->[1];
            my %process_tags =
            (
                'form' => { 'action' => 1 },
                'img' => { 'src' => 1},
                'a' => { 'href' => 1},
                'link' => { 'href' => 1},
            );
            if (exists($process_tags{$tag}))
            {
                my $ret = "<$tag";
                my $attrseq = $token->[3];
                my $attr_values = $token->[2];
                my $process_attrs = $process_tags{$tag};
                foreach my $attr (@$attrseq)
                {
                    my $value = $attr_values->{$attr};
                    if (exists($process_attrs->{$attr}))
                    {
                        # If it's a local link that ends with slash - 
                        # then append index.html
                        if (($value !~ /^[a-z]+:/) && ($value !~ /^\//) &&
                            ($value =~ /\/(#[^#\/]*)?$/))
                        {
                            my $pos = rindex($value, "/");
                            substr($value,$pos+1,0) = "index.html";
                        }
                    }
                    if ($attr eq "/")
                    {
                        $ret .= " /";
                    }
                    else
                    {
                        $ret .= " $attr=\"$value\"";
                    }
                }
                $out->($ret);
                $out->(">");
            }
            else
            {
                $out->($token->[4]);
            }
        }
    }

    return $out_content;    
}

sub process_file
{
    my $self = shift;
    my $file = shift;

    my $dest_dir = $self->_get_dest_dir();
    my $src_dir = $self->_get_base_dir();
    local (*I, *O);
    open I, "<$src_dir/$file" || die "Cannot open '$src_dir/$file' - $!";
    open O, ">$dest_dir/$file" || die "Cannot open '$dest_dir/$file' for writing- $!";
    print O $self->process_content(\*I);
    close(I);
    close(O);
}

sub process_dir_tree
{
    my $self = shift;

    my %args = @_;

    my $should_replace_file = sub {
        my ($src, $dest) = @_;
        if ($args{'only-newer'})
        {
            return ((! -e $dest) || (_is_newer($src, $dest)));
        }
        else
        {
            return 1;
        }
    };

    my $src_dir = $self->_get_base_dir();
    my $dest_dir = $self->_get_dest_dir();

    my (@dirs, @other_files, @html_files);

    my $wanted = sub {
        my $filename = $File::Find::name;
        if (length($filename) < length($src_dir))
        {
            return;
        }
        # Remove the $src_dir from the filename;
        $filename = substr($filename, length($src_dir));
        
        if (-d $_)
        {
            push @dirs, $filename;
        }
        elsif (/\.html?$/)
        {
            push @html_files, $filename;
        }
        else
        {
            push @other_files, $filename;
        }
    };

    find($wanted, $src_dir);

    my $soft_mkdir = sub {
        my $dir = shift;
        if (-d $dir)
        {
            # Do nothing
        }
        elsif (-e $dir)
        {
            die "$dir exists in destination and is not a directory";
        }
        else
        {
            mkdir($dir) || die "mkdir failed: $!\n";
        }
    };

    # Create the directory structure in $dest
    
    $soft_mkdir->($dest_dir);
    foreach my $dir (@dirs)
    {
        $soft_mkdir->("$dest_dir/$dir");
    }

    foreach my $file (@other_files)
    {
        my $src = "$src_dir/$file";
        my $dest = "$dest_dir/$file";
        if ($should_replace_file->($src, $dest))
        {
            copy($src, $dest);
        }
    }

    foreach my $file (@html_files)
    {
        my $src = "$src_dir/$file";
        my $dest = "$dest_dir/$file";
        if ($should_replace_file->($src,$dest))
        {
            $self->process_file($file);
        }
    }

    return 0;
}

1;