diff options
Diffstat (limited to 'activerecord/lib/active_record/migration.rb')
| -rw-r--r-- | activerecord/lib/active_record/migration.rb | 293 |
1 files changed, 173 insertions, 120 deletions
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb index 2c306d233a..f6321f1499 100644 --- a/activerecord/lib/active_record/migration.rb +++ b/activerecord/lib/active_record/migration.rb @@ -1,6 +1,3 @@ -require 'active_support/core_ext/kernel/singleton_class' -require 'active_support/core_ext/module/aliasing' - module ActiveRecord # Exception that can be raised to stop migrations from going backwards. class IrreversibleMigration < ActiveRecordError @@ -43,11 +40,11 @@ module ActiveRecord # Example of a simple migration: # # class AddSsl < ActiveRecord::Migration - # def self.up + # def up # add_column :accounts, :ssl_enabled, :boolean, :default => 1 # end # - # def self.down + # def down # remove_column :accounts, :ssl_enabled # end # end @@ -63,7 +60,7 @@ module ActiveRecord # Example of a more complex migration that also needs to initialize data: # # class AddSystemSettings < ActiveRecord::Migration - # def self.up + # def up # create_table :system_settings do |t| # t.string :name # t.string :label @@ -77,7 +74,7 @@ module ActiveRecord # :value => 1 # end # - # def self.down + # def down # drop_table :system_settings # end # end @@ -138,7 +135,7 @@ module ActiveRecord # in the <tt>db/migrate/</tt> directory where <tt>timestamp</tt> is the # UTC formatted date and time that the migration was generated. # - # You may then edit the <tt>self.up</tt> and <tt>self.down</tt> methods of + # You may then edit the <tt>up</tt> and <tt>down</tt> methods of # MyNewMigration. # # There is a special syntactic shortcut to generate migrations that add fields to a table. @@ -147,11 +144,11 @@ module ActiveRecord # # This will generate the file <tt>timestamp_add_fieldname_to_tablename</tt>, which will look like this: # class AddFieldnameToTablename < ActiveRecord::Migration - # def self.up + # def up # add_column :tablenames, :fieldname, :string # end # - # def self.down + # def down # remove_column :tablenames, :fieldname # end # end @@ -179,11 +176,11 @@ module ActiveRecord # Not all migrations change the schema. Some just fix the data: # # class RemoveEmptyTags < ActiveRecord::Migration - # def self.up + # def up # Tag.find(:all).each { |tag| tag.destroy if tag.pages.empty? } # end # - # def self.down + # def down # # not much we can do to restore deleted data # raise ActiveRecord::IrreversibleMigration, "Can't recover the deleted tags" # end @@ -192,12 +189,12 @@ module ActiveRecord # Others remove columns when they migrate up instead of down: # # class RemoveUnnecessaryItemAttributes < ActiveRecord::Migration - # def self.up + # def up # remove_column :items, :incomplete_items_count # remove_column :items, :completed_items_count # end # - # def self.down + # def down # add_column :items, :incomplete_items_count # add_column :items, :completed_items_count # end @@ -206,11 +203,11 @@ module ActiveRecord # And sometimes you need to do something in SQL not abstracted directly by migrations: # # class MakeJoinUnique < ActiveRecord::Migration - # def self.up + # def up # execute "ALTER TABLE `pages_linked_pages` ADD UNIQUE `page_id_linked_page_id` (`page_id`,`linked_page_id`)" # end # - # def self.down + # def down # execute "ALTER TABLE `pages_linked_pages` DROP INDEX `page_id_linked_page_id`" # end # end @@ -223,7 +220,7 @@ module ActiveRecord # latest column data from after the new column was added. Example: # # class AddPeopleSalary < ActiveRecord::Migration - # def self.up + # def up # add_column :people, :salary, :integer # Person.reset_column_information # Person.find(:all).each do |p| @@ -243,7 +240,7 @@ module ActiveRecord # You can also insert your own messages and benchmarks by using the +say_with_time+ # method: # - # def self.up + # def up # ... # say_with_time "Updating salaries..." do # Person.find(:all).each do |p| @@ -286,144 +283,200 @@ module ActiveRecord # # In application.rb. # + # == Reversible Migrations + # + # Starting with Rails 3.1, you will be able to define reversible migrations. + # Reversible migrations are migrations that know how to go +down+ for you. + # You simply supply the +up+ logic, and the Migration system will figure out + # how to execute the down commands for you. + # + # To define a reversible migration, define the +change+ method in your + # migration like this: + # + # class TenderloveMigration < ActiveRecord::Migration + # def change + # create_table(:horses) do + # t.column :content, :text + # t.column :remind_at, :datetime + # end + # end + # end + # + # This migration will create the horses table for you on the way up, and + # automatically figure out how to drop the table on the way down. + # + # Some commands like +remove_column+ cannot be reversed. If you care to + # define how to move up and down in these cases, you should define the +up+ + # and +down+ methods as before. + # + # If a command cannot be reversed, an + # <tt>ActiveRecord::IrreversibleMigration</tt> exception will be raised when + # the migration is moving down. + # + # For a list of commands that are reversible, please see + # <tt>ActiveRecord::Migration::CommandRecorder</tt>. class Migration - @@verbose = true - cattr_accessor :verbose + autoload :CommandRecorder, 'active_record/migration/command_recorder' class << self - def up_with_benchmarks #:nodoc: - migrate(:up) - end + attr_accessor :delegate # :nodoc: + end - def down_with_benchmarks #:nodoc: - migrate(:down) - end + def self.method_missing(name, *args, &block) # :nodoc: + (delegate || superclass.delegate).send(name, *args, &block) + end - # Execute this migration in the named direction - def migrate(direction) - return unless respond_to?(direction) + cattr_accessor :verbose - case direction - when :up then announce "migrating" - when :down then announce "reverting" - end + attr_accessor :name, :version - result = nil - time = Benchmark.measure { result = send("#{direction}_without_benchmarks") } + def initialize + @name = self.class.name + @version = nil + @connection = nil + end - case direction - when :up then announce "migrated (%.4fs)" % time.real; write - when :down then announce "reverted (%.4fs)" % time.real; write - end + # instantiate the delegate object after initialize is defined + self.verbose = true + self.delegate = new - result - end + def up + self.class.delegate = self + return unless self.class.respond_to?(:up) + self.class.up + end + + def down + self.class.delegate = self + return unless self.class.respond_to?(:down) + self.class.down + end - # Because the method added may do an alias_method, it can be invoked - # recursively. We use @ignore_new_methods as a guard to indicate whether - # it is safe for the call to proceed. - def singleton_method_added(sym) #:nodoc: - return if defined?(@ignore_new_methods) && @ignore_new_methods + # Execute this migration in the named direction + def migrate(direction) + return unless respond_to?(direction) - begin - @ignore_new_methods = true + case direction + when :up then announce "migrating" + when :down then announce "reverting" + end - case sym - when :up, :down - singleton_class.send(:alias_method_chain, sym, "benchmarks") + time = nil + ActiveRecord::Base.connection_pool.with_connection do |conn| + @connection = conn + if respond_to?(:change) + if direction == :down + recorder = CommandRecorder.new(@connection) + suppress_messages do + @connection = recorder + change + end + @connection = conn + time = Benchmark.measure { + recorder.inverse.each do |cmd, args| + send(cmd, *args) + end + } + else + time = Benchmark.measure { change } end - ensure - @ignore_new_methods = false + else + time = Benchmark.measure { send(direction) } end + @connection = nil end - def write(text="") - puts(text) if verbose + case direction + when :up then announce "migrated (%.4fs)" % time.real; write + when :down then announce "reverted (%.4fs)" % time.real; write end + end - def announce(message) - version = defined?(@version) ? @version : nil + def write(text="") + puts(text) if verbose + end - text = "#{version} #{name}: #{message}" - length = [0, 75 - text.length].max - write "== %s %s" % [text, "=" * length] - end + def announce(message) + text = "#{version} #{name}: #{message}" + length = [0, 75 - text.length].max + write "== %s %s" % [text, "=" * length] + end - def say(message, subitem=false) - write "#{subitem ? " ->" : "--"} #{message}" - end + def say(message, subitem=false) + write "#{subitem ? " ->" : "--"} #{message}" + end - def say_with_time(message) - say(message) - result = nil - time = Benchmark.measure { result = yield } - say "%.4fs" % time.real, :subitem - say("#{result} rows", :subitem) if result.is_a?(Integer) - result - end + def say_with_time(message) + say(message) + result = nil + time = Benchmark.measure { result = yield } + say "%.4fs" % time.real, :subitem + say("#{result} rows", :subitem) if result.is_a?(Integer) + result + end - def suppress_messages - save, self.verbose = verbose, false - yield - ensure - self.verbose = save - end + def suppress_messages + save, self.verbose = verbose, false + yield + ensure + self.verbose = save + end - def connection - ActiveRecord::Base.connection - end + def connection + @connection || ActiveRecord::Base.connection + end - def method_missing(method, *arguments, &block) - arg_list = arguments.map{ |a| a.inspect } * ', ' + def method_missing(method, *arguments, &block) + arg_list = arguments.map{ |a| a.inspect } * ', ' - say_with_time "#{method}(#{arg_list})" do - unless arguments.empty? || method == :execute - arguments[0] = Migrator.proper_table_name(arguments.first) - end - connection.send(method, *arguments, &block) + say_with_time "#{method}(#{arg_list})" do + unless arguments.empty? || method == :execute + arguments[0] = Migrator.proper_table_name(arguments.first) end + return super unless connection.respond_to?(method) + connection.send(method, *arguments, &block) end + end - def copy(destination, sources, options = {}) - copied = [] + def copy(destination, sources, options = {}) + copied = [] - FileUtils.mkdir_p(destination) unless File.exists?(destination) + FileUtils.mkdir_p(destination) unless File.exists?(destination) - destination_migrations = ActiveRecord::Migrator.migrations(destination) - last = destination_migrations.last - sources.each do |name, path| - source_migrations = ActiveRecord::Migrator.migrations(path) + destination_migrations = ActiveRecord::Migrator.migrations(destination) + last = destination_migrations.last + sources.each do |name, path| + source_migrations = ActiveRecord::Migrator.migrations(path) - source_migrations.each do |migration| - source = File.read(migration.filename) - source = "# This migration comes from #{name} (originally #{migration.version})\n#{source}" + source_migrations.each do |migration| + source = File.read(migration.filename) + source = "# This migration comes from #{name} (originally #{migration.version})\n#{source}" - if duplicate = destination_migrations.detect { |m| m.name == migration.name } - options[:on_skip].call(name, migration) if File.read(duplicate.filename) != source && options[:on_skip] - next - end + if duplicate = destination_migrations.detect { |m| m.name == migration.name } + options[:on_skip].call(name, migration) if File.read(duplicate.filename) != source && options[:on_skip] + next + end - migration.version = next_migration_number(last ? last.version + 1 : 0).to_i - new_path = File.join(destination, "#{migration.version}_#{migration.name.underscore}.rb") - old_path, migration.filename = migration.filename, new_path - last = migration + migration.version = next_migration_number(last ? last.version + 1 : 0).to_i + new_path = File.join(destination, "#{migration.version}_#{migration.name.underscore}.rb") + old_path, migration.filename = migration.filename, new_path + last = migration - FileUtils.cp(old_path, migration.filename) - copied << migration - options[:on_copy].call(name, migration, old_path) if options[:on_copy] - destination_migrations << migration - end + FileUtils.cp(old_path, migration.filename) + copied << migration + options[:on_copy].call(name, migration, old_path) if options[:on_copy] + destination_migrations << migration end - - copied end - def next_migration_number(number) - if ActiveRecord::Base.timestamped_migrations - [Time.now.utc.strftime("%Y%m%d%H%M%S"), "%.14d" % number].max - else - "%.3d" % number - end + copied + end + + def next_migration_number(number) + if ActiveRecord::Base.timestamped_migrations + [Time.now.utc.strftime("%Y%m%d%H%M%S"), "%.14d" % number].max + else + "%.3d" % number end end end @@ -451,7 +504,7 @@ module ActiveRecord def load_migration require(File.expand_path(filename)) - name.constantize + name.constantize.new end end |