(This was originally posted to the Catalyst Mailing List. It's being reposted on PerlMonks for the benefit of the broader Perl community.)

Squatting is a web microframework for Perl that's based on Camping from the Ruby world. During the transition from Ruby to Perl, Squatting gained some mutant powers which is why I'm writing to you today.

One of Squatting's mutant powers is its ability to embed itself into other frameworks (like Catalyst). You can take whole Squatting apps, and embed them into your existing web application with just a few lines of glue code. Allow me to demonstrate.

STEP 1: Install Pod::Server from CPAN.

$ sudo cpan Pod::Server

STEP 2: Run Pod::Server so you can see what it looks like.

$ squatting Pod::Server -p 8088 or $ pod_server

Then, visit http://localhost:8088/ and pay attention to the URLs as you click around. (This will be interesting when you see how the URLs of the whole site will be "relocated" later on in the demonstration.)

STEP 3: Create a Catalyst application.

$ catalyst.pl Propaganda

STEP 4: Embed Pod::Server into the Catalyst application.

$ cd Propaganda $ $EDITOR lib/Propaganda/Controller/Root.pm

Then, add the following lines of code to an appropriate place in the controller.

use Pod::Server ’On::Catalyst’; Pod::Server->init; Pod::Server->relocate(’/pod’); $Pod::Simple::HTML::Perldoc_URL_Prefix = ’/pod/’; sub pod : Local { Pod::Server->catalyze($_[1]) }

STEP 5: Start up the Catalyst application.

$ script/propaganda_server.pl

Finally, visit http://localhost:3000/pod/. If everything worked, you should see that Pod::Server has just been embedded into a Catalyst application.

What Are The Implications of This?

Right now, anyone who is developing a web app with Catalyst can install Pod::Server from CPAN and embed it directly into their web app. However, this is just the beginning.

Imagine if you could install a blog, a wiki, a forum, or a store just as easily.

Imagine adding major functionality to any Perl-based site with ~5 lines of code.

Squatting makes modular web applications both possible and probable.