So in most cases, you??™ll deal with acts_as_
list along with models that have data associations, and when that is the case, the acts_as_list
method will generally go in the model that has the belongs_to method, as you can see here:
class TopTenTopics < ActiveRecord::Base
has_many :top_ten_items
end
class TopTenItems < ActiveRecord::Base
belongs_to :top_ten_topics
acts_as_list :scope => :top_ten_topic
end
Because we cover data associations in detail in Chapter 4, we will not dive into the design
issues of the TopTen associations at this time. Just know that a given top-ten topic record would
have a number of associated top-ten item records for this example.
CHAPTER 5 ?– BONUS FEATURES 93
Step 2: Defining an Integer Column Used for Sorting the List
Sometimes, like with a grocery list, you won??™t really care about the order of the list, but that
doesn??™t mean that it doesn??™t have an order. The list has a beginning and an end, and each item
is either before or after other items on the list. In fact, order is a basic and fundamental element
of all lists, so it should come as no surprise that, to use acts_as_list, within Active Record you
need to have an integer field within your database that stores the order of items within your list.
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