module Rails::Generators::Migration

Holds common methods for migrations. It assumes that migrations has the [0-9]*_name format and can be used by another frameworks (like Sequel) just by implementing the next migration version method.

Attributes

migration_class_name[R]
migration_file_name[R]
migration_number[R]

Public Instance Methods

migration_template(source, destination=nil, config={}) click to toggle source

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.

Examples

migration_template "migration.rb", "db/migrate/add_foo_to_bar.rb"
# File lib/rails/generators/migration.rb, line 45
def migration_template(source, destination=nil, config={})
  destination = File.expand_path(destination || source, self.destination_root)

  migration_dir = File.dirname(destination)
  @migration_number     = self.class.next_migration_number(migration_dir)
  @migration_file_name  = File.basename(destination).sub(/\.rb$/, '')
  @migration_class_name = @migration_file_name.camelize

  destination = self.class.migration_exists?(migration_dir, @migration_file_name)

  if !(destination && options[:skip]) && behavior == :invoke
    if destination && options.force?
      remove_file(destination)
    elsif destination
      raise Error, "Another migration is already named #{@migration_file_name}: #{destination}"
    end
    destination = File.join(migration_dir, "#{@migration_number}_#{@migration_file_name}.rb")
  end

  template(source, destination, config)
end