[Solved] Best approach to implement model? (Many-to-Many, polymorphic) (Page 2 of 2)

I already had the foreign key on the valuable side, but can't get the value from a property_valuation. I tried changing has_one/belongs_to but apparently I can't simply change has_one by belongs_to, as I'll get this error:

i.properties.push(p)                                               
ArgumentError: Unknown key: polymorphic

I'm assuming the idea was to mantain the rest without changes:

class PropertyValuation < ActiveRecord::Base
  attr_accessible :valuable
  attr_accessor :valuable
  
  belongs_to :property
  belongs_to :item
  has_one :valuable, :polymorphic => true
end

class DecimalValue < ActiveRecord::Base
  attr_accessible :value
  
  belongs_to :property_valuation, :as => :valuable
end

Migrations:

class CreateDecimalValues < ActiveRecord::Migration
  def change
    create_table :decimal_values do |t|
      t.decimal :value
      t.references :property_valuation

      t.timestamps
    end
  end
end

class CreatePropertyValuations < ActiveRecord::Migration
  def change
    create_table :property_valuations do |t|
      t.references :item
      t.references :property
      t.references :valuable, :polymorphic => true

      t.timestamps
    end
    add_index :property_valuations, :item_id
    add_index :property_valuations, :property_id
    add_index :property_valuations, :valuable_id
  end
end

Last edited by imnotnot (2012-10-29 15:16:03)

I revised the Railscast for polymorphic associations (railscasts.com/episodes/154-polymorphic-association), but I found my behavior to be different from their example: in my case I'm trying to associate something which has many forms (DecimalValue, TextValue, etc) to a model (PropertyValuation). On the contrary, they are associating a Comment to something which has many forms (Image, Post, etc).
Can this invalidate the use of a polymorphic association in my scenario?

EDIT: Apparently I found many reported issues related to the use of has_one in a polymorphic association. I also found this (http://stackoverflow.com/a/5140580/554972) which seems interesting to try, but didn't work.

Last edited by imnotnot (2012-10-31 06:55:30)