Module: ActsAsList::ClassMethods

This acts_as extension provides the capabilities for sorting and reordering a number of objects in a list. The class that has this specified needs to have a position column defined as an integer on the mapped database table.

Todo list example:

  class TodoList < ActiveRecord::Base
    has_many :todo_items, :order => "position"
  end

  class TodoItem < ActiveRecord::Base
    belongs_to :todo_list
    acts_as_list :scope => :todo_list
  end

  todo_list.first.move_to_bottom
  todo_list.last.move_higher

Methods

acts_as_list acts_as_list

Public Instance methods

acts_as_list(options = {})

Configuration options are:

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 it hasn‘t already been added) 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‘

[Source]

    # File lib/acts_as_list.rb, line 31
31:     def acts_as_list(options = {})
32:       configuration = { :column => "position", :scope => "1 = 1" }
33:       configuration.update(options) if options.is_a?(Hash)
34: 
35:       configuration[:scope] = "#{configuration[:scope]}_id".intern if configuration[:scope].is_a?(Symbol) && configuration[:scope].to_s !~ /_id$/
36: 
37:       if configuration[:scope].is_a?(Symbol)
38:         scope_condition_method = %(
39:           def scope_condition
40:             if #{configuration[:scope].to_s}.nil?
41:               "#{configuration[:scope].to_s} IS NULL"
42:             else
43:               "#{configuration[:scope].to_s} = \#{#{configuration[:scope].to_s}}"
44:             end
45:           end
46:         )
47:       else
48:         scope_condition_method = "def scope_condition() \"#{configuration[:scope]}\" end"
49:       end
50: 
51:       class_eval "include ActsAsList::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\nbefore_destroy :remove_from_list\nbefore_create  :add_to_list_bottom\n"
52:     end

acts_as_list(options = {})

Configuration options are:

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 it hasn‘t already been added) 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‘

[Source]

    # File lib/acts_as_list.rb, line 31
31:     def acts_as_list(options = {})
32:       configuration = { :column => "position", :scope => "1 = 1" }
33:       configuration.update(options) if options.is_a?(Hash)
34: 
35:       configuration[:scope] = "#{configuration[:scope]}_id".intern if configuration[:scope].is_a?(Symbol) && configuration[:scope].to_s !~ /_id$/
36: 
37:       if configuration[:scope].is_a?(Symbol)
38:         scope_condition_method = %(
39:           def scope_condition
40:             if #{configuration[:scope].to_s}.nil?
41:               "#{configuration[:scope].to_s} IS NULL"
42:             else
43:               "#{configuration[:scope].to_s} = \#{#{configuration[:scope].to_s}}"
44:             end
45:           end
46:         )
47:       else
48:         scope_condition_method = "def scope_condition() \"#{configuration[:scope]}\" end"
49:       end
50: 
51:       class_eval "include ActsAsList::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\nbefore_destroy :remove_from_list\nbefore_create  :add_to_list_bottom\n"
52:     end