Rails引擎-注册一个ActiveRecord类型

Question

在标准Rails应用程序中，很容易注册自定义ActiveRecord类型:

例如config/initializers/duration_type.rb:

class DurationType < ActiveRecord::Type::String
def cast(value)
return value if value.blank? || value.is_a?(ActiveSupport::Duration)
ActiveSupport::Duration.parse(value)
end
def serialize(duration)
duration ? duration.iso8601 : nil
end
end
ActiveRecord::Type.register(:duration, DurationType)

如何在rails引擎中实现相同的功能?

Answer 1

我想这样的东西即使没有railtie也能工作:

# my_gem/lib/my_gem/duration_type.rb
class MyGem::DurationType < ActiveRecord::Type::String
def cast(value)
return value if value.blank? || value.is_a?(ActiveSupport::Duration)
ActiveSupport::Duration.parse(value)
end
def serialize(duration)
duration ? duration.iso8601 : nil
end
end
ActiveSupport.on_load(:active_record) do
ActiveRecord::Type.register :duration, MyGem::DurationType
end