Using CGI, DBI, and GD::Graph, I am creating a basic reporting application. I would like the charts in this application to have image maps which will enable the user to drill down on any given data point of any given chart.

A good drill down has two parts.
First, rollover should be enabled so the user can see the values that are represented by a given data point.
Second, the user should be able to click on a given data point, generating a new chart that is more narrowly focused on his/her selection.
GD::Graph::Map appears to be the perfect solution for this. So far, though, I have not been able to get the data point links (hrefs option of the GD::Graph::Maps object) or the rollover information (info options of the same object) to work. Whenever I generate a chart, the data points are hyperlinked, but the link itself is the default link for the GD::Graph::Maps object, which is "javascript:;". The rollover values also do not get substituted (%x should be substituted by the x-axis value, %y substituted by the y-axis value -- i actually get %x,%y). Here's my script in its entirety: 
#!C:\perl\bin\perl.exe
use strict;
use warnings;
use CGI ':standard';
use GD::Graph::lines;
use GD::Graph::Map;
use DBI;
use Data::Dumper;

my $db = "...";
my $user = "...";
my $pwd = "...";

my $dbh = DBI->connect("DBI:DB2:$db", "$user", "$pwd", {RaiseError => 
+0, AutoCommit => 1});
my $stmt = "...";
my $sth = $dbh->prepare($stmt);
my $rc = $sth->execute;
my $data = $sth->fetchall_arrayref;
$sth->finish;

my @dates = ();
my @values = ();
my @urls = ();
my $baseURL = "http://localhost:8080/cgi-bin/index.cgi?date=";

foreach my $entry (@$data){
  push(@dates, $entry->[0]);
  push(@values, $entry->[1]);
  push(@urls, $baseURL . $entry->[0]);
}

my @chartData = ([@dates], [@values]);
my $graph = GD::Graph::lines->new(1300, 600);
$graph->set(
    x_label => 'Date',
    y_label => 'Transaction Count',
    title => 'Transaction Counts by Day',
    y_max_value => 2500,
    y_min_value => 0,
    y_tick_number => 10,
    y_label_skip => 2,
    box_axis => undef,
    line_width => 2,
);

open(CHART, ">../htdocs/chart.png") or die;
binmode CHART;
print CHART $graph->plot(\@chartData)->png;
close(CHART);

my $map = new GD::Graph::Map($graph,
        hrefs=>\@urls,
        noImgMarkup=>0,
        mapName=>"chartmap",
        info=>'%x,%y',
    );

print
  header,
  start_html('Simple Script'),
  h1('Simple Script'),
  hr,
  img({src=>"/chart.png", usemap=>"#chartmap"}),
  ($map->imagemap("chart.png", \@chartData));
print end_html;

print Dumper @dates;
print Dumper @values;
print Dumper @urls;

[download]

If run from the command line, it produces the following output: 
<title>Simple Script</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1
+" />
</head>
<body>
<h1>Simple Script</h1><hr /><img usemap="#chartmap" src="/chart.png" /
+><Map Name=chartmap>
    <Area Shape=polygon Coords="82, 433, 122, 326, 163, 383, 203, 370,
+ 244, 344, 284, 443, 325, 457, 366, 424, 406, 422, 447, 329, 487, 376
+, 528, 322, 569, 310, 609, 364, 650, 338, 690, 322, 731, 346, 771, 35
+8, 812, 408, 853, 442, 893, 451, 934, 421, 974, 284, 1015, 356, 1056,
+ 374, 1096, 408, 1137, 416, 1177, 465, 1218, 440, 1258, 381, 1258, 38
+5, 1218, 444, 1177, 469, 1137, 420, 1096, 412, 1056, 378, 1015, 360, 
+974, 288, 934, 425, 893, 455, 853, 446, 812, 412, 771, 362, 731, 350,
+ 690, 326, 650, 342, 609, 368, 569, 314, 528, 326, 487, 380, 447, 333
+, 406, 426, 366, 428, 325, 461, 284, 447, 244, 348, 203, 374, 163, 38
+7, 122, 330, 82, 437" Href="javascript:;" Title="%x,%y" Alt="%x,%y" o
+nMouseOver="window.status='%x,%y'; return true;" onMouseOut="window.s
+tatus=''; return true;">
</Map>

</body>
</html>$VAR1 = '2009-06-01';
$VAR2 = '2009-06-02';
$VAR3 = '2009-06-03';
$VAR4 = '2009-06-04';
$VAR5 = '2009-06-05';
$VAR6 = '2009-06-06';
$VAR7 = '2009-06-07';
$VAR8 = '2009-06-08';
$VAR9 = '2009-06-09';
$VAR10 = '2009-06-10';
$VAR11 = '2009-06-11';
$VAR12 = '2009-06-12';
$VAR13 = '2009-06-13';
$VAR14 = '2009-06-14';
$VAR15 = '2009-06-15';
$VAR16 = '2009-06-16';
$VAR17 = '2009-06-17';
$VAR18 = '2009-06-18';
$VAR19 = '2009-06-19';
$VAR20 = '2009-06-20';
$VAR21 = '2009-06-21';
$VAR22 = '2009-06-22';
$VAR23 = '2009-06-23';
$VAR24 = '2009-06-24';
$VAR25 = '2009-06-25';
$VAR26 = '2009-06-26';
$VAR27 = '2009-06-27';
$VAR28 = '2009-06-28';
$VAR29 = '2009-06-29';
$VAR30 = '2009-06-30';
$VAR1 = '612';
$VAR2 = '1099';
$VAR3 = '842';
$VAR4 = '899';
$VAR5 = '1016';
$VAR6 = '567';
$VAR7 = '504';
$VAR8 = '654';
$VAR9 = '665';
$VAR10 = '1085';
$VAR11 = '871';
$VAR12 = '1120';
$VAR13 = '1174';
$VAR14 = '929';
$VAR15 = '1047';
$VAR16 = '1118';
$VAR17 = '1008';
$VAR18 = '954';
$VAR19 = '729';
$VAR20 = '574';
$VAR21 = '534';
$VAR22 = '668';
$VAR23 = '1292';
$VAR24 = '965';
$VAR25 = '880';
$VAR26 = '727';
$VAR27 = '689';
$VAR28 = '470';
$VAR29 = '582';
$VAR30 = '852';
$VAR1 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-01';
$VAR2 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-02';
$VAR3 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-03';
$VAR4 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-04';
$VAR5 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-05';
$VAR6 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-06';
$VAR7 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-07';
$VAR8 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-08';
$VAR9 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-09';
$VAR10 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-10';
$VAR11 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-11';
$VAR12 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-12';
$VAR13 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-13';
$VAR14 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-14';
$VAR15 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-15';
$VAR16 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-16';
$VAR17 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-17';
$VAR18 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-18';
$VAR19 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-19';
$VAR20 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-20';
$VAR21 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-21';
$VAR22 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-22';
$VAR23 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-23';
$VAR24 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-24';
$VAR25 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-25';
$VAR26 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-26';
$VAR27 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-27';
$VAR28 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-28';
$VAR29 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-29';
$VAR30 = 'http://localhost:8080/cgi-bin/index.cgi?date=2009-06-30';

[download]
The webpage itself looks fine, just no datapoint rollover info or hyperlinks. I see where that data is wrong in the Area tag, I just don't understand what I should be doing for it to be set correctly.

Update:
I should point out this is a browser-based reporting app.
Update2:
When I switch from a line chart to a pie chart, the hrefs and rollovers work. Is that functionality broken with the line charts?

In reply to Problem with GD::Graph::Map hrefs and info options by jrsimmon

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.