column - specifies the column name to use for keeping the position
integer (default: position)
scope - restricts what is to be considered a list. Given a symbol,
it’ll attach "_id" (if that hasn’t been already) and
use that as the foreign key restriction. It’s also possible to give
it an entire string that is interpolated if you need a tighter scope than
just a foreign key. Example: acts_as_list
:scope => 'todo_list_id = #{todo_list_id} AND completed = 0'
# File activerecord/lib/active_record/acts/list.rb, line 34
def acts_as_list(options = {})
configuration = { :column => "position", :scope => "1 = 1" }
configuration.update(options) if options.is_a?(Hash)
configuration[:scope] = "#{configuration[:scope]}_id".intern if configuration[:scope].is_a?(Symbol) && configuration[:scope].to_s !~ /_id$/
if configuration[:scope].is_a?(Symbol)
scope_condition_method = %(
def scope_condition
if #{configuration[:scope].to_s}.nil?
"#{configuration[:scope].to_s} IS NULL"
else
"#{configuration[:scope].to_s} = \#{#{configuration[:scope].to_s}}"
end
end
)
else
scope_condition_method = "def scope_condition() \"#{configuration[:scope]}\" end"
end
class_eval "include ActiveRecord::Acts::List::InstanceMethods\n\ndef acts_as_list_class\n::\#{self.name}\nend\n\ndef position_column\n'\#{configuration[:column]}'\nend\n\n\#{scope_condition_method}\n\nafter_destroy :remove_from_list\nbefore_create :add_to_list_bottom\n"
end