检查是否在before_save事件上修改或创建了模型

Question

我想检查是否在Rails的before_save回调中创建了一个模型.我还想检查它是否已被修改(更新时).

谢谢

Answer 1

您可以使用new_record?以查看是否有全新的对象并changed?查看是否有任何更改:

before_save :pancakes

def pancakes
    if new_record?
        # Not in the database yet.
    elsif changed?
        # Already exists but it has unsaved changes.
    end
end