Ruby on Rails内联around_save回调产生一个LocalJumpError

Question

在Rails 3.0.5和Ruby 1.9.3中,是否可以around_save使用around_save声明内联定义回调体？

也就是说,我注意到这个案例正常:

around_save :around_save_body
def around_save_body
  puts 'before save'
  yield 
  puts 'after save'
end

[114] pry(main)> a = Activity.find(57)
=> #<Activity id: 57, ... >

[115] pry(main)> a.save
before save
after save
=> true

然而,如果我将主体内联,我得到一个LocalJumpError:

around_save do |activity|
  puts 'before save'
  yield 
  puts 'after save'
end

[117] pry(main)> a = Activity.find(57)
=> #<Activity id: 57, ... >

[118] pry(main)> a.save
before save
LocalJumpError: no block given (yield)
from /home/maksim/hkn/website/app/models/activity.rb:47:in `block in <class:Activity>'

我试图改变yield到yield activity在第二个例子,但我得到了相同的结果.是否有可能让我的around_save身体与around_save声明一致？

Answer 1

在这种情况下,ActiveRecord将传递一个Proc作为第二个参数,只需执行以下操作:

around_save do |activity, block|
  puts 'before save'
  block.call
  puts 'after save'
end