Module | Sequel::Plugins::List::InstanceMethods |
In: |
lib/sequel/plugins/list.rb
|
When destroying an instance, move all entries after the instance down one position, so that there aren‘t any gaps
# File lib/sequel/plugins/list.rb, line 94 94: def after_destroy 95: super 96: 97: f = Sequel[position_field] 98: list_dataset.where(f > position_value).update(f => f - 1) 99: end
The model object at the given position in the list containing this instance.
# File lib/sequel/plugins/list.rb, line 88 88: def at_position(p) 89: list_dataset.first(position_field => p) 90: end
Find the last position in the list containing this instance.
# File lib/sequel/plugins/list.rb, line 102 102: def last_position 103: list_dataset.max(position_field).to_i 104: end
A dataset that represents the list containing this instance.
# File lib/sequel/plugins/list.rb, line 107 107: def list_dataset 108: model.scope_proc ? model.scope_proc.call(self) : model.dataset 109: end
Move this instance down the given number of places in the list, or 1 place if no argument is specified.
# File lib/sequel/plugins/list.rb, line 113 113: def move_down(n = 1) 114: move_to(position_value + n) 115: end
Move this instance to the given place in the list. Raises an exception if target is less than 1 or greater than the last position in the list.
# File lib/sequel/plugins/list.rb, line 119 119: def move_to(target, lp = nil) 120: current = position_value 121: if target != current 122: checked_transaction do 123: ds = list_dataset 124: op, ds = if target < current 125: target = 1 if target < 1 126: [:+, ds.filter(position_field=>target...current)] 127: else 128: lp ||= last_position 129: target = lp if target > lp 130: [:-, ds.filter(position_field=>(current + 1)..target)] 131: end 132: ds.update(position_field => Sequel::SQL::NumericExpression.new(op, position_field, 1)) 133: update(position_field => target) 134: end 135: end 136: self 137: end
Move this instance to the bottom (last position) of the list.
# File lib/sequel/plugins/list.rb, line 140 140: def move_to_bottom 141: lp = last_position 142: move_to(lp, lp) 143: end
Move this instance to the top (first position, position 1) of the list.
# File lib/sequel/plugins/list.rb, line 146 146: def move_to_top 147: move_to(1) 148: end
Move this instance the given number of places up in the list, or 1 place if no argument is specified.
# File lib/sequel/plugins/list.rb, line 152 152: def move_up(n = 1) 153: move_to(position_value - n) 154: end
The model instance the given number of places below this model instance in the list, or 1 place below if no argument is given.
# File lib/sequel/plugins/list.rb, line 158 158: def next(n = 1) 159: n == 0 ? self : at_position(position_value + n) 160: end
The value of the model‘s position field for this instance.
# File lib/sequel/plugins/list.rb, line 163 163: def position_value 164: get_column_value(position_field) 165: end