Handles the reversing of reversible migrations. Basically records supported methods calls, translates them to reversed calls, and returns them in reverse order.
Public Class methods
new()
[show source]
# File lib/sequel/extensions/migration.rb 181 def initialize 182 @actions = [] 183 end
Public Instance methods
reverse(&block)
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.
[show source]
# File lib/sequel/extensions/migration.rb 188 def reverse(&block) 189 begin 190 instance_exec(&block) 191 rescue 192 just_raise = true 193 end 194 if just_raise 195 Proc.new{raise Sequel::Error, "irreversible migration method used in #{block.source_location.first}, you may need to write your own down method"} 196 else 197 actions = @actions.reverse 198 Proc.new do 199 actions.each do |a| 200 pr = a.last.is_a?(Proc) ? a.pop : nil 201 # Allow calling private methods as the reversing methods are private 202 send(*a, &pr) 203 end 204 end 205 end 206 end