Switch to Catalyst!

So this week, as previously alluded to, I convinced my boss to let me switch my current app from CGI::Application to Catalyst. I had gotten the book in the mail and I showed it to him to make the point that it’s a serious framework. Fortunately the switch has been mostly painless. The first reason being that our controller is pretty bare right now aside from validation, which took about a day to get entirely ironed out.

The interesting thing for me, most of all, is that I have gotten pretty good at writing regular expressions with vim to search and replace for CGIApp-isms to replace with Cat-isms.

Here are a list of some of the big ones:

Simple replacements:

:%s/return/$c->stash->{json} =

More complex stuff

:%s/$self->query->param(\(.\{-}\) = $c->request->params->{\1}
:%s/method (.\{-}) : Runmode/method \1($c) : Local
:%s/$self->schema->resultset(\s*'\(.\{-}\)'\s*) = $c->model('DB::\1')

If you know anything about regular expressions you know that the \1 means the first back reference. Now, vim’s regex flavor is a little strange because it is optimized for searching for plain text, so *most* characters default to literals. That’s why I have to escape the parentheses to make a matching group. Also note the following unusual construct: .\{-} . That’s the same as .*? in Perl. That’s actually surprisingly important.

Anyway, this switch has been fairly fun and exciting. The best part being the inimitable structure of a Catalyst application. For example, the fact that we have a dev server with lots of affordances for (duh) developers other than little setup is great, and built in config file reading is something that I have always wanted. We always ended up rolling our own solution in other projects, but this is really supreme since it’s in one place and not just Perl code.

An there are lots of pleasant things like how it’s really easy for our app to have both JSON and TT support. This will be really good later on when we start to do pdf printouts and whatnot. Instead of adding methods for those things into the controller, like in CGIApp, we will just add another View module.

The main thing that has weirded my out so far is that in CGIApp the App is the controller. In Catalyst you have an App, which also seems to be an instance variable, with accessors for CGI parameters and whatnot, and you also have Controllers. Anyway, I need to wrap my head around all that. Hopefully reading through the book will help with some of these issues.

How about you? Are you still happy with CGIApp? Are you adventurous enough to use Reaction?

Posted Fri, Jul 17, 2009

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