小编Gna*_*gno的帖子

我有一个关于活动记录关联的问题,请参考rails文档的这一部分:

http://guides.rubyonrails.org/association_basics.html#the-has_many-through-association

如果我们有三个型号:

class Physician < ActiveRecord::Base
  has_many :appointments
  has_many :patients, :through => :appointments
end

class Appointment < ActiveRecord::Base
  belongs_to :physician
  belongs_to :patient
end

class Patient < ActiveRecord::Base
  has_many :appointments
  has_many :physicians, :through => :appointments
end

文档说可以通过api以这种方式管理连接模型的集合:

physician.patients = patients

但是,如果约会模型(如链接示例中)有一个名为appointment_date的字段,并且我想在特定日期为医生和患者创建新约会,该怎么办？以下代码将在约会表中创建一条记录,但是如何在第三步中填充appointment_date呢？

physician = Physician.first
patient = Patients.first
physician.patients << patient

这样的事情存在吗？

physician.patients.create( :patient => patient, 'appointment.appointment_time' => appointment_time ) 

假设我有这个类(直接取自aasm文档):

class Job < ActiveRecord::Base
  include AASM

  aasm do
    state :sleeping, :initial => true
    state :running
    state :cleaning

    event :run do
      transitions :from => :sleeping, :to => :running
    end

    event :clean do
      transitions :from => :running, :to => :cleaning
    end

    event :sleep do
      transitions :from => [:running, :cleaning], :to => :sleeping
    end
  end

end

我不喜欢我的状态机定义与我的类定义混合的事实(因为当然在实际项目中我会向Job类添加更多方法).

我想在模块中分离状态机定义,以便Job类可以是以下内容:

class Job < ActiveRecord::Base
  include StateMachines::JobStateMachine
end

然后我在app/models/state_machines中创建了一个job_state_machine.rb文件,其内容类似于:

module StateMachines::JobStateMachine
  include AASM

  aasm do
    state :sleeping, :initial => true
    state :running
    state :cleaning

    event …