dry application architecture

Hi everyone.
In my company we developed a rails cms and now we are trying to figure
out how to use it in the smartest way.

We would like to use our modules, wich are mvc for common site elements
like 'pages', 'posts', 'news', 'feed' etc, as svn externals in every
site project. In this way if we find a bug in the cms core we can easily
update every site we made.

In the same time we would like to make possible to extend our core
modules for customizing them if needed.

We thought this directory structure would be nice:

  ... other rails dirs ...
  /modules # <-- here we want to put svn:external to cms modules

the extension of core modules will be put on site_project/app as a
normal rails application. If we don't put an extension we want to load
the related module.

E.g. in the directory i put before if i define
site_project/app/models/page this file will be loaded but if my
application will need post.rb the modules file will be loaded.

I know i didn't explain very clear I hope someone would understant
enough to help me, even because i bet it's a common problem for studios
that use rails for web developing.

best regards.

Gabriel, the way I do this personally is to put my
models/views/controllers/helpers in a plugin, and then have the plugin
loaded via the engines plugin.

If you're using all subversion repositories for everything, you can
use svn:externals to point to your plugin and you should be good to
go. If not, I recently released a rubygem called 'ext' that lets me
do svn:externals-like stuff with git, so I use that to manage
subprojects. For example, the engines repository is managed via git
so if you use svn:externals you would have to check the whole engines
repository into your main projects' repositories. I personally find
that kind of annoying to do, especially if you make modifications to
the engines repository (which I had to) since you would then have to
go to all your projects and fix the engines plugins there as well (or
even just to do a git pull to get the latest engines changes would
require making a commit to every main project that uses engines.)
Those type of annoyances are what inspired me to make ext.

Either way, take a look at the engines plugin and see if you can use
it to solve this problem, as I had success with the engines plugin.