Class Sequel::MigrationReverser
In: lib/sequel/extensions/migration.rb
lib/sequel/extensions/pg_enum.rb
Parent: Sequel::BasicObject

Handles the reversing of reversible migrations. Basically records supported methods calls, translates them to reversed calls, and returns them in reverse order.

Methods

new   reverse  

Public Class methods

[Source]

     # File lib/sequel/extensions/migration.rb, line 164
164:     def initialize
165:       @actions = []
166:     end

Public Instance methods

Reverse the actions for the given block. Takes the block given and returns a new block that reverses the actions taken by the given block.

[Source]

     # File lib/sequel/extensions/migration.rb, line 171
171:     def reverse(&block)
172:       begin
173:         instance_eval(&block)
174:       rescue
175:         just_raise = true
176:       end
177:       if just_raise
178:         Proc.new{raise Sequel::Error, 'irreversible migration method used, you may need to write your own down method'}
179:       else
180:         actions = @actions.reverse
181:         Proc.new do
182:           actions.each do |a|
183:             if a.last.is_a?(Proc)
184:               pr = a.pop
185:               send(*a, &pr)
186:             else
187:               send(*a)
188:             end
189:           end
190:         end
191:       end
192:     end

[Validate]