diff options
Diffstat (limited to 'activerecord/lib/active_record/migration/command_recorder.rb')
| -rw-r--r-- | activerecord/lib/active_record/migration/command_recorder.rb | 122 |
1 files changed, 80 insertions, 42 deletions
diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb index 95f4360578..13ce28330a 100644 --- a/activerecord/lib/active_record/migration/command_recorder.rb +++ b/activerecord/lib/active_record/migration/command_recorder.rb @@ -16,69 +16,116 @@ module ActiveRecord class CommandRecorder include JoinTable - attr_accessor :commands, :delegate + attr_accessor :commands, :delegate, :reverting def initialize(delegate = nil) @commands = [] @delegate = delegate + @reverting = false + end + + # While executing the given block, the recorded will be in reverting mode. + # All commands recorded will end up being recorded reverted + # and in reverse order. + # For example: + # + # recorder.revert{ recorder.record(:rename_table, [:old, :new]) } + # # same effect as recorder.record(:rename_table, [:new, :old]) + def revert + @reverting = !@reverting + previous = @commands + @commands = [] + yield + ensure + @commands = previous.concat(@commands.reverse) + @reverting = !@reverting end # record +command+. +command+ should be a method name and arguments. # For example: # # recorder.record(:method_name, [:arg1, :arg2]) - def record(*command) - @commands << command + def record(*command, &block) + if @reverting + @commands << inverse_of(*command, &block) + else + @commands << (command << block) + end end - # Returns a list that represents commands that are the inverse of the - # commands stored in +commands+. For example: + # Returns the inverse of the given command. For example: # - # recorder.record(:rename_table, [:old, :new]) - # recorder.inverse # => [:rename_table, [:new, :old]] + # recorder.inverse_of(:rename_table, [:old, :new]) + # # => [:rename_table, [:new, :old]] # # This method will raise an +IrreversibleMigration+ exception if it cannot - # invert the +commands+. - def inverse - @commands.reverse.map { |name, args| - method = :"invert_#{name}" - raise IrreversibleMigration unless respond_to?(method, true) - send(method, args) - } + # invert the +command+. + def inverse_of(command, args, &block) + method = :"invert_#{command}" + raise IrreversibleMigration unless respond_to?(method, true) + send(method, args, &block) end def respond_to?(*args) # :nodoc: super || delegate.respond_to?(*args) end - [:create_table, :create_join_table, :change_table, :rename_table, :add_column, :remove_column, :rename_index, :rename_column, :add_index, :remove_index, :add_timestamps, :remove_timestamps, :change_column, :change_column_default, :add_reference, :remove_reference].each do |method| + [:create_table, :create_join_table, :rename_table, :add_column, :remove_column, + :rename_index, :rename_column, :add_index, :remove_index, :add_timestamps, :remove_timestamps, + :change_column, :change_column_default, :add_reference, :remove_reference, :transaction, + :drop_join_table, :drop_table, :remove_index, + :change_column, :execute, :remove_columns, # irreversible methods need to be here too + ].each do |method| class_eval <<-EOV, __FILE__, __LINE__ + 1 - def #{method}(*args) # def create_table(*args) - record(:"#{method}", args) # record(:create_table, args) - end # end + def #{method}(*args, &block) # def create_table(*args, &block) + record(:"#{method}", args, &block) # record(:create_table, args, &block) + end # end EOV end alias :add_belongs_to :add_reference alias :remove_belongs_to :remove_reference - private - - def invert_create_table(args) - [:drop_table, [args.first]] + def change_table(table_name, options = {}) + yield ConnectionAdapters::Table.new(table_name, self) end - def invert_create_join_table(args) - table_name = find_join_table_name(*args) + private - [:drop_table, [table_name]] + module StraightReversions + private + { transaction: :transaction, + create_table: :drop_table, + create_join_table: :drop_join_table, + add_column: :remove_column, + add_timestamps: :remove_timestamps, + add_reference: :remove_reference, + }.each do |cmd, inv| + [[inv, cmd], [cmd, inv]].each do |method, inverse| + class_eval <<-EOV, __FILE__, __LINE__ + 1 + def invert_#{method}(args, &block) # def invert_create_table(args, &block) + [:#{inverse}, args, block] # [:drop_table, args, block] + end # end + EOV + end + end + end + + include StraightReversions + + def invert_drop_table(args, &block) + if args.size == 1 && block == nil + raise ActiveRecord::IrreversibleMigration, "To avoid mistakes, drop_table is only reversible if given options or a block (can be empty)." + end + super end def invert_rename_table(args) [:rename_table, args.reverse] end - def invert_add_column(args) - [:remove_column, args.first(2)] + def invert_remove_column(args) + raise ActiveRecord::IrreversibleMigration, "remove_column is only reversible if given a type." if args.size <= 2 + super end def invert_rename_index(args) @@ -91,27 +138,18 @@ module ActiveRecord def invert_add_index(args) table, columns, options = *args - index_name = options.try(:[], :name) - options_hash = index_name ? {:name => index_name} : {:column => columns} - [:remove_index, [table, options_hash]] + [:remove_index, [table, (options || {}).merge(column: columns)]] end - def invert_remove_timestamps(args) - [:add_timestamps, args] - end + def invert_remove_index(args) + table, options = *args + raise ActiveRecord::IrreversibleMigration, "remove_index is only reversible if given a :column option." unless options && options[:column] - def invert_add_timestamps(args) - [:remove_timestamps, args] + options = options.dup + [:add_index, [table, options.delete(:column), options]] end - def invert_add_reference(args) - [:remove_reference, args] - end alias :invert_add_belongs_to :invert_add_reference - - def invert_remove_reference(args) - [:add_reference, args] - end alias :invert_remove_belongs_to :invert_remove_reference # Forwards any missing method call to the \target. |