CGI Application Modules for CPAN

Listing 11 4 shows the new _edit() method. Now all the code does is load the 

template using CGI::Application's load_tmpl() method. This method takes the 

name of an HTML::Template template file and calls HTML::Template >new() to load 

it, returning the new HTML::Template object. Next, if the user is replying to a 

message, the reply_id template parameter is set using HTML::Template's param()

method. This method works similarly to the CGI.pm param() method, but instead 

of accessing CGI parameters it sets variables declared in the template with .

Finally, the template output is generated using the output() method and 

returned. Yes, it really is that simple!

Listing 11 5, the template file (edit.tmpl) used in Listing 11 4, is a bit more 

complicated, but you can blame HTML for that. It's unfortunate that no one 

thought to ask Larry Wall to design the markup language for the Web! However, 

since this is mostly plain HTML, there are many skilled designers available to take 

this stuff off your hands. The only part of this template that's not plain HTML is the 

section that optionally sets up the reply_id parameter:

This section uses two of HTML::Template's special tags,  and ,

to conditionally include the reply_id hidden field in the form. I don't have time 

to explore HTML::Template fully here for that see the HTML::Template 

documentation.

The benefits of this approach are numerous. By separating the HTML from the 

code that drives the application, both can be made simpler. Furthermore, people 

with different skills can work more efficiently on the part of the application they 

know best. In this example, I could spend my time working on adding features to 

the BBS.pm file while an HTML designer works on making the form easier to look at 

and use. In addition, as I'll demonstrate later, a proper use of templating is critical 

to allowing your CGI applications to be reused by others.

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