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,4th,5th]&data1=[1,2,3,4,5]&data2=[6,7,8,9,10]&dclrs=[blue,yellow,green]
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 GD::Graph(3). 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 GD::Graph(3).
- 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.