Module: ActiveRecord::Acts::List::ClassMethods
- Defined in:
- vendor/plugins/acts_as_list/lib/active_record/acts/list.rb
Overview
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
Instance Method Summary
-
- (Object) acts_as_list(options = {})
Configuration options are:.
Instance Method Details
- (Object) 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’
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# File 'vendor/plugins/acts_as_list/lib/active_record/acts/list.rb', line 33 def acts_as_list( = {}) configuration = { :column => "position", :scope => "1 = 1" } configuration.update() if .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\nbefore_destroy :remove_from_list\nbefore_create :add_to_list_bottom\n" end |