| Module | ActsAsList::InstanceMethods |
| In: |
lib/acts_as_list.rb
|
All the methods available to a record that has had acts_as_list specified. Each method works by assuming the object to be the item in the list, so chapter.move_lower would move that chapter lower in the list of all chapters. Likewise, chapter.first? would return true if that chapter is the first in the list of all chapters.
Decrease the position of this item without adjusting the rest of the list.
# File lib/acts_as_list.rb, line 136
136: def decrement_position
137: return unless in_list?
138: update_attribute position_column, self.send(position_column).to_i - 1
139: end
Return true if this object is the first in the list.
# File lib/acts_as_list.rb, line 142
142: def first?
143: return false unless in_list?
144: self.send(position_column) == 1
145: end
Return the next higher item in the list.
# File lib/acts_as_list.rb, line 154
154: def higher_item
155: return nil unless in_list?
156: acts_as_list_class.find(:first, :conditions =>
157: "#{scope_condition} AND #{position_column} < #{send(position_column).to_s}", :order => "#{position_column} DESC"
158: )
159: end
Test if this record is in a list
# File lib/acts_as_list.rb, line 170
170: def in_list?
171: !send(position_column).nil?
172: end
Increase the position of this item without adjusting the rest of the list.
# File lib/acts_as_list.rb, line 130
130: def increment_position
131: return unless in_list?
132: update_attribute position_column, self.send(position_column).to_i + 1
133: end
Insert the item at the given position (defaults to the top position of 1).
# File lib/acts_as_list.rb, line 77
77: def insert_at(position = 1)
78: insert_at_position(position)
79: end
Return true if this object is the last in the list.
# File lib/acts_as_list.rb, line 148
148: def last?
149: return false unless in_list?
150: self.send(position_column) == bottom_position_in_list
151: end
Return the next lower item in the list.
# File lib/acts_as_list.rb, line 162
162: def lower_item
163: return nil unless in_list?
164: acts_as_list_class.find(:first, :conditions =>
165: "#{scope_condition} AND #{position_column} > #{send(position_column).to_s}", :order => "#{position_column} ASC"
166: )
167: end
Swap positions with the next higher item, if one exists.
# File lib/acts_as_list.rb, line 92
92: def move_higher
93: higher = higher_item
94: return unless higher
95: acts_as_list_class.transaction do
96: self.update_attribute(position_column, higher.send(position_column))
97: higher.increment_position
98: end
99: end
Swap positions with the next lower item, if one exists.
# File lib/acts_as_list.rb, line 82
82: def move_lower
83: lower = lower_item
84: return unless lower
85: acts_as_list_class.transaction do
86: self.update_attribute(position_column, lower.send(position_column))
87: lower.decrement_position
88: end
89: end
Move to the bottom of the list. If the item is already in the list, the items below it have their position adjusted accordingly.
# File lib/acts_as_list.rb, line 103
103: def move_to_bottom
104: return unless in_list?
105: acts_as_list_class.transaction do
106: decrement_positions_on_lower_items
107: assume_bottom_position
108: end
109: end
Move to the top of the list. If the item is already in the list, the items above it have their position adjusted accordingly.
# File lib/acts_as_list.rb, line 113
113: def move_to_top
114: return unless in_list?
115: acts_as_list_class.transaction do
116: increment_positions_on_higher_items
117: assume_top_position
118: end
119: end