[Catalyst] sane migration to catalyst

[Wade.Stuart at fallon.com]

> Hi Catalisters
>
> I spent a few spare hours in the last weeks working through the
> tutorial, and I think I've convinced myself that this is the
> direction I want to go in.
>

Great!  The learning curve can be a bit steep until you start playing with
it.

> The problem I now have is that I have an existing site, with a small
> userbase, running under modperl (most of the scripts were cgi and
> now run under the registry module), that needs to be kept going and
> growing. It's pretty simple, with basic auth and no cookies or
> sessions as such - though there would be advantages to moving over
> to these techniques later, especially for some future stuff I want to do.
>
> What I need to do is try to migrate progressively, as I add new
> features. I'm having a bit of trouble seeing the wood for the trees
> at the moment though, especially as the current "wishlist" is pretty
long.


For what its worth, when given any option whatsoever I would try to migrate
the entire app at one time.  I have worked on projects such as these where
portions of the code or functionality were migrated or updated piecemeal.
They
have always been nightmares.  It seems no matter how much time you put
into it that doing migrations part-by-part while the old app is live leads
to messy code.  There are always cases where you need to build up special
cases in the new code to deal with the old code's behavior -- after the
code is migrated you have to go back and clean that up yet again.
It takes away some of the very core of why you may want to migrate in
the first place -- to simplify, extend and document.

So for my money,  let the old app live while you migrate to the new
app -- put the new app in place when it is ready.

>
> I know this is a bit vague, but do any of the old hands here have
> any tips for handling this? Running normal Apache::Registry based
> stuff alongside catalyst apps? And so on?

If for some reason you must do this peicemeal,  you have many options.

What OS, Apache version etc are you running on?