NAME
    Apache::GD::Graph - Generate Charts in an Apache handler.

SYNOPSIS
    In httpd.conf:

            PerlModule Apache::GD::Graph

            <Location /chart>
            SetHandler      perl-script
            PerlHandler     Apache::GD::Graph
            # These are optional.
            PerlSetVar      Expires         30 # days.
            PerlSetVar      CacheSize       5242880 # 5 megs.
            </Location>

    Then send requests to:

    `http://www.server.com/chart?type=lines&x_labels=[1st,2nd,3rd,4t
    h,5th]&data1=[1,2,3,4,5]&data2=[6,7,8,9,10]&dclrs=[blue,yellow,g
    reen]'

INSTALLATION
    Like any other CPAN module, if you are not familiar with CPAN
    modules, see:
    http://www.cpan.org/doc/manual/html/pod/perlmodinstall.html .

DESCRIPTION
    The primary purpose of this module is to allow a very easy to
    use, lightweight and fast charting capability for static pages,
    dynamic pages and CGI scripts, with the chart creation process
    abstracted and placed on any server.

    For example, embedding a pie chart can be as simple as:

            <img src="http://www.some-server.com/chart?type=pie&x_labels=[greed,pride,wrath]&data1=[10,50,20]&dclrs=[green,purple,red]" alt="pie chart of a few deadly sins">
            <!-- Note that all of the above options are optional except for data1!  -->

    And it gets cached both server side, and along any proxies to
    the client, and on the client's browser cache. Not to mention,
    chart generation is very fast.

    It is implemented as a simple Apache mod_perl handler that
    generates and returns a png format graph (using Martien
    Verbruggen's GD::Graph module) based on the arguments passed in
    via a query string. It responds with the content-type
    "image/png" directly, and sends a Expires: header of 30 days (or
    whatever is set via `PerlSetVar Expires', in days) ahead. In
    addition, it keeps a server-side cache in the file system using
    DeWitt Clinton's File::Cache module, whose size can be specified
    via `PerlSetVar CacheSize' in bytes.

OPTIONS
    type    Type of graph to generate, can be lines, bars, points,
            linespoints, area, mixed, pie. For a description of
            these, see the GD::Graph(3) manpage. Can also be one of
            the 3d types if GD::Graph3d is installed, or anything
            else with prefix GD::Graph::.

    width   Width of graph in pixels, 400 by default.

    height  Height of graph in pixels, 300 by default.

    For the following, look at the plot method in the GD::Graph(3)
    manpage.

    x_labels
            Labels used on the X axis, the first array given to the
            plot method of GD::Graph.

    dataN   Values to plot, where N is a number starting with 1. Can be
            given any number of times with N increasing.

    ALL OTHER OPTIONS are passed as a hash to the GD::Graph set
    method using the following rules for the values:

    undef   Becomes a real undef.

    [one,two,3]
            Becomes an array reference.

    {one,1,two,2}
            Becomes a hash reference.

    http://somewhere/file.png
            Is pulled into a file and the file name is passed to the
            respective option. (Can be any scheme besides http://
            that LWP::Simple supports.)

AUTHOR
    Rafael Kitover (caelum@debian.org)

COPYRIGHT
    This program is Copyright (c) 2000 by Rafael Kitover. This
    program is free software; you can redistribute it and/or modify
    it under the same terms as Perl itself.

ACKNOWLEDGEMENTS
    This module owes its existance, obviously, to the availability
    of the wonderful GD::Graph module from Martien Verbruggen.

    Thanks to my employer, marketingmoney.com, for allowing me to
    work on projects as free software.

    Thanks to Vivek Khera for the bug fixes.

BUGS
    Probably a few.

TODO
    More extensive test suite. Need to be easily able to generate
    graphs without axes.

SEE ALSO
    the perl manpage, the GD::Graph manpage, the GD manpage