Chapter 11

An example of a CGI project that wouldn't make an ideal module might be a 

search application. Typically search functionality is tightly integrated into the 

underlying data and user interface of a Web site. It may still be possible to solve 

this problem with CGI::Application, but the results are unlikely to be usable on 

other sites.

Configurability

The primary goal of a successful CGI::Application module on CPAN has to be con 

figurability. These applications will live in a varied environment, and their mode of 

operation has to be flexible. For example, the CGI::Application::MailPage module,

6

which provides a  mail this page to a friend  application for static HTML documents, 

is configurable in how it sends mail, what options it offers to its users, and how it 

accesses the underlying documents. For example, here's a typical instance script 

used with CGI::Application::MailPage:

#!/usr/bin/perl

use CGI::Application::MailPage;

my $mailpage = CGI::Application::MailPage >new(

                  PARAMS => { document_root  =>  /home/httpd ,

                              smtp_server    =>  smtp.foo.org ,

                              use_page_param => 1,

                            });

$mailpage >run();

Template Usage

All CGI::Application modules on CPAN will have to use templating of some sort to 

be widely reusable. Otherwise it would be impossible for the output of the module 

to be reconfigured to match the look of the site where it is being used. However, 

this doesn't mean that CGI::Application modules should require users to provide 

their own templates. The modules should come with a default set with simple 

HTML formatting. This serves two purposes. First, it provides an example for users 

to build off of. Second, it allows users to more easily evaluate the module and test 

its functionality.

One issue does arise in packaging default templates how will the module 

find them after installation? Perl doesn't (yet!) support a default template path, so 

you'll have to do something about it yourself. The technique I used in building 

6. I wrote CGI::Application::MailPage as a proof of concept in building a CGI::Application 

for CPAN.

270