[Catalyst] proper flow control with $c->foward, in search of greater grok

Tomas Doran bobtfish at bobtfish.net
Fri Jan 8 14:55:43 GMT 2010

Dennis Daupert wrote:
> It seems that when chained path parts increase beyond two links, 
> addressing actions directly doesn't work quite as well. For example, I 
> have these:
> User.pm
> User::Blog.pm
> User::Blog::Entry.pm
> After I add an entry to blog 'x' for user 'y', I can transport over to 
> the entries list for blog 'x' like so:
> $c->forward($c->controller('My::Controller::User::Blog::Entry')->action_for('list'), 
> [ @args ]);
> $c->detach;

Right, but forward visits _one action_, only..

> Or less elegantly, like so:
> $c->response->redirect($c->uri_for("/user/$user_id/blog/$blog_id/entry/list"));

Eww, don't do that.

You want
[$user_id, $blog_id]));

And it should be noted that redirect and forward are _totally_ different 
things, used for totally different purposes.

> But I can't seem to _go_ to the list (this doesn't work -- I get 
> 'invalid ID'):
> $c->go( 'My::Controller::User::Blog::Entry', 'list', [ \@captures, 
> \@args ] );

Not specific enough. You get 'invalid ID' where, from what?

Please show use the debug table from app startup and for the hit in 
question which has the issue?

At a guess what you're doing wrong is not ->go ing to the end of the 
chain - you can _only_ go to chain endpoints (rather than individual 
actions) as go does a full redispatch.

> Are there built-in limits to number of chained links we can dispatch by 
> way of directly addressing actions?


> Any rules/tips/guidelines in 
> multiple chained situations?

USE ACTION OBJECTS OR uri_for_action.

That is all :)


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