Listing 3: Final Version of Apache::TagNew

package Apache::TagNew;
use strict;
use Apache::Constants qw(OK DECLINED NOT_FOUND);
use Apache::Session::DBI;
sub handler
  {
    # Get the Apache request object
    my $r = shift;
    # Only handle text/html files
    return DECLINED unless ($r->content_type 
    eq "text/html");
    # Get the user's session ID, if it exists
    my $id = $r->header_in('Cookie');
    $id =~ s/SESSION_ID=(\w*)/$1/;
    # Get the user's session, if it exists
    my %session;
    tie %session, 'Apache::Session::DBI', $id,
      {
       DataSource => 'dbi:mysql:test:localhost:3306',
       UserName   => '',
       Password   => ''
      };

    # Set the session information for this URL
    my $document_uri = $r->uri;
    $session{$document_uri} = time;
    # Create a cookie based on the ID, and send that 
    # as part of the return header
    my $session_cookie = 
    "SESSION_ID=$session{_session_id};";
    $r->header_out("Set-Cookie" => 
    $session_cookie);
    # Get the file we're trying to send
    if (open(FILE, $r->filename))
      {
	# Send an appropriate MIME header
	$r->send_http_header;
	# Slurp up files at once
	undef $/;
	# Grab the file's contents
	my ($contents) = (<FILE>);
	# Tag hyperlinks as new
	$contents =~ 
	s|<a\s+href=['"]?(\S+?)['"]?\s*>([\s\S]+?)</a>
	|label_url($r, $1, $2, \%session)|eigx;
	# Print the contents
	$r->print($contents);
	# Close the file handle
	close FILE;

	# Indicate that all went well
	return OK;
      }
    # produce an appropriate error message
    else
      {
	return NOT_FOUND;
      }
  }


# Subroutine for tagging URLs
sub label_url
  {
    # Get the URL and the text
    my $r = shift;
    my $url = shift;
    my $text = shift;
    my $session = shift;
    my %session = %{$session};
    my $label;
    # If the URL does not begin with "http://", 
    #then we can assume it
    # is on our system
    if ($url !~ m|^http://|)
      {
	# If the first character of our URL is not a /,
	# then we must prepend the current directory to it
	if ($url !~ m|^/|)
	  {
	    # Get the current directory, based on the URL
	    my $current_directory = $r->uri;
	    $current_directory =~ s|^(\S+/)[\w.]+$|$1|;

	    # Now prepend it
	    $url = $current_directory . $url;
	  }
	# When was the last time we saw this URL?
	my $last_time = (time - $session{$url}) / 86400;
	# When was this file last modified?
	my $full_filename = $r->document_root . $url;
	my $ctime = -M $full_filename;
	# Check to see when we last accessed this URL
	if ($ctime < $last_time)
	  {
	    $label = "<font color=\"red\">New!</font>";
	  }
      }

    # Return a value to the caller
    return "<a href=\"$url\">$text</a> $label";
  }
1;