条件模型更新-Rails 3.1

Question

I have two tables:

stores raw_stores_data

The raw_stores_data is received from a third party daily.

I'd update certain fields of the stores model if those fields have been modified for that record in raw_stores_data.

Currently I have a bunch of conditional statements that check each of those fields. Is there any better way to code this?

new_data = raw_stores_data.all.select do |item|
   item.store_id.present?
end

new_data.each do |item|
  if item.field1 != item.stores.field1
  ...
  ...
  ...

  # update record with hash of fields to update created above
end

Answer 1

You could add an association and special mutators to the 'raw' model that know how manipulate the 'stores' object. This serves to keep the model code in the model. Thin controller, comprehensive models, etc.

class Store < ActiveRecord::Base
  has_one :raw_stores_data
end


class RawStoresData < ActiveRecord::Base
  belongs_to :store

  def field1=(value)
    store.field1 = value
    store.save!
    field1 = value
  end
end

I'm hand waving at some of the details, and you might want to reverse the direction of the association or make it go both directions.

EDIT:

You would use this as such:

raw_data = RawStoreData.find(param[:id]) # or new or however you get this object
raw_data.field1 = param[:field1]

The act of assigning will use the 'field1=' method, and make the change to the associated store object. If you're worried about saving unnecessarily, you could conditionalize in that method to only save if the value changed.

I hope this is clearer.