Comments on: before_filter and with_scope http://marcus.ahnve.net/2006/05/09/before_filter-and-with_scope/ A northern, icebears-on-the-streets, view on programming, music etc. from Marcus Ahnve Fri, 21 Nov 2008 04:16:01 +0000 http://wordpress.org/?v=2.6 By: Jon Tirsen http://marcus.ahnve.net/2006/05/09/before_filter-and-with_scope/#comment-644 Jon Tirsen Tue, 09 May 2006 01:06:16 +0000 http://marcus.ahnve.net/?p=126#comment-644 <p>I've been digging into this too. No you can't use either a before<em>filter or an around</em>filter to do this using the public API. The problem is that around<em>filter's in Rails aren't actually around</em>filter's they're more like a before/around-filter combo. A real around_filter could do:</p> <p>class ScopingFilter def around DomainObject.with_scope(...) do yield # passes control to controller end end end</p> <p>But unfortunately Rails isn't capable of that. So instead the plugin has to use module_eval to dive into the private parts of the domain object and chuck in a scope in the "before" part of the "around" filter then dive in again and yank it out in the "after" part.</p> <p>Ugly? Oh yeaaaah... Pretty brutal rummaging around with another objects private parts like that.</p> <p>Maybe it's time somebody teaches Rails Core what "around" really means...</p> I’ve been digging into this too. No you can’t use either a beforefilter or an aroundfilter to do this using the public API. The problem is that aroundfilter’s in Rails aren’t actually aroundfilter’s they’re more like a before/around-filter combo. A real around_filter could do:

class ScopingFilter def around DomainObject.with_scope(…) do yield # passes control to controller end end end

But unfortunately Rails isn’t capable of that. So instead the plugin has to use module_eval to dive into the private parts of the domain object and chuck in a scope in the “before” part of the “around” filter then dive in again and yank it out in the “after” part.

Ugly? Oh yeaaaah… Pretty brutal rummaging around with another objects private parts like that.

Maybe it’s time somebody teaches Rails Core what “around” really means…

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