Module Sequel::Plugins::List::InstanceMethods
In: lib/sequel/plugins/list.rb

Methods

Public Instance methods

The model object at the given position in the list containing this instance.

[Source]

    # File lib/sequel/plugins/list.rb, line 91
91:         def at_position(p)
92:           list_dataset.first(position_field => p)
93:         end

Set the value of the position_field to the maximum value plus 1 unless the position field already has a value.

[Source]

     # File lib/sequel/plugins/list.rb, line 97
 97:         def before_create
 98:           unless send(position_field)
 99:             send("#{position_field}=", list_dataset.max(position_field).to_i+1)
100:           end
101:           super
102:         end

Find the last position in the list containing this instance.

[Source]

     # File lib/sequel/plugins/list.rb, line 105
105:         def last_position
106:           list_dataset.max(position_field).to_i
107:         end

A dataset that represents the list containing this instance.

[Source]

     # File lib/sequel/plugins/list.rb, line 110
110:         def list_dataset
111:           model.scope_proc ? model.scope_proc.call(self) : model.dataset
112:         end

Move this instance down the given number of places in the list, or 1 place if no argument is specified.

[Source]

     # File lib/sequel/plugins/list.rb, line 116
116:         def move_down(n = 1)
117:           move_to(position_value + n)
118:         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.

[Source]

     # File lib/sequel/plugins/list.rb, line 122
122:         def move_to(target, lp = nil)
123:           current = position_value
124:           if target != current
125:             checked_transaction do
126:               ds = list_dataset
127:               op, ds = if target < current
128:                 raise(Sequel::Error, "Moving too far up (target = #{target})") if target < 1
129:                 [:+, ds.filter(position_field=>target...current)]
130:               else
131:                 lp ||= last_position
132:                 raise(Sequel::Error, "Moving too far down (target = #{target}, last_position = #{lp})") if target > lp
133:                 [:-, ds.filter(position_field=>(current + 1)..target)]
134:               end
135:               ds.update(position_field => Sequel::SQL::NumericExpression.new(op, position_field, 1))
136:               update(position_field => target)
137:             end
138:           end
139:           self
140:         end

Move this instance to the bottom (last position) of the list.

[Source]

     # File lib/sequel/plugins/list.rb, line 143
143:         def move_to_bottom
144:           lp = last_position 
145:           move_to(lp, lp)
146:         end

Move this instance to the top (first position, position 1) of the list.

[Source]

     # File lib/sequel/plugins/list.rb, line 149
149:         def move_to_top
150:           move_to(1)
151:         end

Move this instance the given number of places up in the list, or 1 place if no argument is specified.

[Source]

     # File lib/sequel/plugins/list.rb, line 155
155:         def move_up(n = 1)
156:           move_to(position_value - n) 
157:         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.

[Source]

     # File lib/sequel/plugins/list.rb, line 161
161:         def next(n = 1)
162:           n == 0 ? self : at_position(position_value + n)
163:         end

The value of the model‘s position field for this instance.

[Source]

     # File lib/sequel/plugins/list.rb, line 166
166:         def position_value
167:           send(position_field)
168:         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.

[Source]

     # File lib/sequel/plugins/list.rb, line 172
172:         def prev(n = 1)
173:           self.next(n * -1)
174:         end

[Validate]