Comments on: Ruby on Rails: Polymorphic Associations with Mixin Modules

By: Ali

Ali — Fri, 21 Oct 2011 10:00:00 +0000

Very useful, thanks for sharing, I would suggest using a block rather than a string:

def self.included(base)
base.instance_eval { has_many :impressions, :as => :impressionable }
end

By: How to add a Ruby on Rails association from inside a module/mixin « The Missing Readme

Thu, 23 Sep 2010 02:48:09 +0000

[...] associations in a mixin. Doing so however is a bit of a black art. I found out how to do this from http://www.teachmetocode.com (and the code below includes the hint from Stefan Kanev’s [...]

By: http://charlesmaxwood.com/ruby-on-rails-… « bst On Web Dev

http://charlesmaxwood.com/ruby-on-rails-… « bst On Web Dev — Tue, 18 Aug 2009 00:53:37 +0000

[...] 12:53 am on August 18, 2009 Permalink | Reply Tags: app design, rails (9) http://charlesmaxwood.com/ruby-on-rails-polymorphic-associations-with-mixin-modules/ – Ruby on Rails: Polymorphic Associations with Mixin Modules [...]

By: Rails Metal Example #7: Tracking Analytics

Rails Metal Example #7: Tracking Analytics — Tue, 11 Aug 2009 05:34:07 +0000

[...] week ago, I posted Ruby on Rails: Polymorphic Associations with Mixin Modules which included an example of tracking impressions on different [...]

By: Wojciech

Wojciech — Mon, 03 Aug 2009 07:39:13 +0000

add_impression isn’t necessary, as ActiveRecord’s association proxies provide us with some methods like:
some_record.impressions.create :visitor=>visitor
- no need to pass :impressionable=>self

Of course you can wrap this in a custom method for abstraction:
def impression( visitor ) self.impressions.create :visitor=>visitor end

But I recommend against creating such abstractions until it’s necessary – there’s a good chance ActiveRecord associations will do. You can even extend them, take a look at “association extensions”:
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html

By: drool

drool — Fri, 31 Jul 2009 20:25:57 +0000

This is how DataMapper suggests to handle polymorphic relationships within it (as opposed to using STI).

By: Stefan Kanev

Stefan Kanev — Fri, 31 Jul 2009 18:59:09 +0000

You don’t need the instance eval. You can simply do base.has_many

I tend to end up doing this every time I use a polymorphic relationship