From: leon breedt <bitserf@...>
Date: 2004-07-26T17:20:55+09:00
Subject: aop presentational items in Rails?

hi,

i was just wondering, does Rails offer, or plan to offer,
HTML::Mason-like AOP for templates?

the Masonic notion does not map directly to the Rails way of doing
things, i suspect,
i think the closest thing Rails has to a component in Mason
terminology is the template, and i'll use template below when i mean
"component" in HTML::Mason terms.

with HTML::Mason, you can define a "autohandler" for any particular
path. what this means is that the autohandler is a parent (for the
purposes of presentational output) for any template contained at or
below that path.

it has complete control of the output and can decide where the output
of any contained templates should go. you can obviously override it
selectively for components that you don't want this behaviour to apply
to.

the concept is very powerful though, as the wrapped component need
know nothing about how its being wrapped. this is also vastly superior
to include mechanisms, as it is completely DRYish :)

Mason examples:

   /autohandler           - gets invoked for all paths
   /admin/autohandler - gets invoked for everything below /admin

there is of course also the Mason concept of "dhandler", or "default
handler", when nonexistent paths are attempted to be accessed, but
thats a whole different discussion.

the autohandler feature is something i would not be able to live
without though, as it has meant a vast reduction in LOC for my web
apps.

comments?

leon