# frozen_string_literal: true
require "active_support/concern"
require_relative "actions/create_migration"
module Rails
module Generators
# Holds common methods for migrations. It assumes that migrations have the
# [0-9]*_name format and can be used by other frameworks (like Sequel)
# just by implementing the next migration version method.
module Migration
extend ActiveSupport::Concern
attr_reader :migration_number, :migration_file_name, :migration_class_name
module ClassMethods #:nodoc:
def migration_lookup_at(dirname)
Dir.glob("#{dirname}/[0-9]*_*.rb")
end
def migration_exists?(dirname, file_name)
migration_lookup_at(dirname).grep(/\d+_#{file_name}.rb$/).first
end
def current_migration_number(dirname)
migration_lookup_at(dirname).collect do |file|
File.basename(file).split("_").first.to_i
end.max.to_i
end
def next_migration_number(dirname)
raise NotImplementedError
end
end
def create_migration(destination, data, config = {}, &block)
action Rails::Generators::Actions::CreateMigration.new(self, destination, block || data.to_s, config)
end
def set_migration_assigns!(destination)
destination = File.expand_path(destination, destination_root)
migration_dir = File.dirname(destination)
@migration_number = self.class.next_migration_number(migration_dir)
@migration_file_name = File.basename(destination, ".rb")
@migration_class_name = @migration_file_name.camelize
end
# Creates a migration template at the given destination. The difference
# to the default template method is that the migration version is appended
# to the destination file name.
#
# The migration version, migration file name, migration class name are
# available as instance variables in the template to be rendered.
#
# migration_template "migration.rb", "db/migrate/add_foo_to_bar.rb"
def migration_template(source, destination, config = {})
source = File.expand_path(find_in_source_paths(source.to_s))
set_migration_assigns!(destination)
context = instance_eval("binding")
dir, base = File.split(destination)
numbered_destination = File.join(dir, ["%migration_number%", base].join("_"))
create_migration numbered_destination, nil, config do
ERB.new(::File.binread(source), nil, "-", "@output_buffer").result(context)
end
end
end
end
end