[Catalyst] Re: CatalystSites.org

[Moritz Onken]

>
> Totally depends. I ported an app to Catalyst that previously was
> basically one-action-per-controller. It cannot be called anything
> less than a lot of work, but it paid of royally. The code is as
> DRY as it was before, but it’s now far better structured.
> Previously it was blocks of if-elsif chains grouping together
> execution steps that are shared by some URIs but not others – now
> it’s Chained. A typical controller looks something like this:
>
>    sub base : Chained PathPart('doc') CaptureArgs(0) { ... }
>    sub list : Chained('base') PathPart('') Args(0) { ... }
>    sub item : Chained('base') PathPart('') CaptureArgs(1) { ... }
>    sub view : Chained('item') PathPart('') Args(0) { ... }
>    sub edit : Chained('item') Args(0) { ... }
>
> This gives `/doc` (goes `base` then `list`), `/doc/*` (goes
> `base` then `item` then `view`), and `/doc/*/edit` (goes `base`
> then `item` then `edit`).
>
> And then you can put stuff shared by all actions in `base`[^1],
> and stuff shared by all actions that relate to a single document
> (eg. stuffing that document into the stash) all in `item`.
>
> By liberal use of `PathPart('') CaptureArgs(0)` you can force any
> URI to step down any number of intermediate steps you require, so
> you can use that to group together shared code any way you see
> fit:
>
>    sub foo : Chained CaptureArgs(0) {}
>    sub bar : Chained('foo') PathPart('') CaptureArgs(0) {}
>    sub baz : Chained('bar') PathPart('') CaptureArgs(0) {}
>    sub qux : Chained('baz') Args(0) {}
>
> This will dispatch `/foo/qux` across the entire foo bar baz qux
> chain. Now consider:
>
...


This is the best example I've seen! It would be great if you could  
write this up and put it in the manual or wiki!
I think I finally know how chained works :-)


thanks!