Comments on: How to alias and create a new named scope out of existing ones http://www.rngtng.com/2009/03/26/how-to-alias-and-create-a-new-named-scope-out-of-existing-ones/ TobiTobes Tech Weblog featuring Ruby, Rails, Web development, Arduino, Processing, Geekstuff and more... Thu, 02 Sep 2010 20:26:53 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: David Ongaro http://www.rngtng.com/2009/03/26/how-to-alias-and-create-a-new-named-scope-out-of-existing-ones/comment-page-1/#comment-529 David Ongaro Fri, 04 Jun 2010 12:05:38 +0000 http://urangatang.wordpress.com/?p=8#comment-529 Nice. Even though just defining a method like def self.has_moo_and_foo has_moo. has_foo end also works, I find the named_scope syntax more appealing, because one can scan the named scopes in one sight. (And they also show up in Fu.scopes). When you define the scopes in the right order, the lambda gets superflous though. So named_scope :has_moo_and_foo, has_moo.has_foo.scope(:find) is enough. But default_scope conditions are duplicated in this way (with or without lambda). Even though this doesn't might hurt it seems to be saver to just exclude them: named_scope :has_moo_and_foo, with_exclusive_scope { has_moo.has_foo.scope(:find) } Nice. Even though just defining a method like

def self.has_moo_and_foo
has_moo. has_foo
end

also works, I find the named_scope syntax more appealing, because one can scan the named scopes in one sight. (And they also show up in Fu.scopes).

When you define the scopes in the right order, the lambda gets superflous though. So

named_scope :has_moo_and_foo, has_moo.has_foo.scope(:find)

is enough. But default_scope conditions are duplicated in this way (with or without lambda). Even though this doesn’t might hurt it seems to be saver to just exclude them:

named_scope :has_moo_and_foo, with_exclusive_scope { has_moo.has_foo.scope(:find) }

]]> By: Michael Thompson http://www.rngtng.com/2009/03/26/how-to-alias-and-create-a-new-named-scope-out-of-existing-ones/comment-page-1/#comment-53 Michael Thompson Fri, 18 Sep 2009 08:09:53 +0000 http://urangatang.wordpress.com/?p=8#comment-53 Thanks, this was useful. I had a bunch of anonymous named scopes I needed to chain together, but with OR, rather than AND. It was simple to create a new scope using the collection of #scope(:find)[:conditions] joined with " OR ". Thanks, this was useful. I had a bunch of anonymous named scopes I needed to chain together, but with OR, rather than AND. It was simple to create a new scope using the collection of #scope(:find)[:conditions] joined with ” OR “.

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