Sha256: 75cb87857021e48c4fbcf51e2eeaf2d562a14d6560b40e435e951051bfa00728
Contents?: true
Size: 1.69 KB
Versions: 6
Compression:
Stored size: 1.69 KB
Contents
module ActiveRecord
module PGEnum
register :command_recorder do
require "active_record/migration/command_recorder"
ActiveRecord::Migration::CommandRecorder.include CommandRecorder
end
# ActiveRecord::Migration::CommandRecorder is a class used by reversible migrations.
# It captures the forward migration commands and translates them into their inverse
# by way of some simple metaprogramming.
#
# The Migrator class uses CommandRecorder during the reverse migration instead of
# the connection object. Forward migration calls are translated to their inverse
# where possible, and then forwarded to the connetion. Irreversible migrations
# raise an exception.
#
# Known schema statement methods are metaprogrammed into an inverse method like so:
#
# create_table => invert_create_table
#
# which returns:
#
# [:drop_table, args.first]
module CommandRecorder
def create_enum(*args, &block)
record(:create_enum, args, &block)
end
def drop_enum(*args, &block)
record(:drop_enum, args, &block)
end
def add_enum_value(*args, &block)
record(:add_enum_value, args, &block)
end
private
def invert_create_enum(args)
[:drop_enum, args]
end
def invert_drop_enum(args)
raise ActiveRecord::IrreversibleMigration, "drop_enum is only reversible if given a list of values" unless args.length > 1
[:create_enum, args]
end
def invert_add_enum_value(args)
raise ActiveRecord::IrreversibleMigration, "ENUM values cannot be removed once added. Drop and Replace it instead at your own risk."
end
end
end
end
Version data entries
6 entries across 6 versions & 1 rubygems