帮我重构这个讨厌的Ruby if/else语句

Question

所以我在我的时事通讯分发应用程序中有一个很大的方法。方法是为了更新人造丝，我需要分配一个用户到人造丝。通过具有属性since_date和until_date的表colporteur_in_rayons，我有关系n:n。

我是一个初级程序员，我知道这段代码是相当愚蠢的:)我很欣赏每一个建议。

def update
  rayon = Rayon.find(params[:id])
  if rayon.update_attributes(params[:rayon])
    if params[:user_id] != ""
      unless rayon.users.empty?
        unless rayon.users.last.id.eql?(params[:user_id])
          rayon.colporteur_in_rayons.last.update_attributes(:until_date => Time.now)
          Rayon.assign_user(rayon.id,params[:user_id])
          flash[:success] = "Rayon #{rayon.name} has been succesuly assigned to #{rayon.actual_user.name}."
          return redirect_to rayons_path
        end
      else
         Rayon.assign_user(rayon.id,params[:user_id])
         flash[:success] = "Rayon #{rayon.name} has been successfully assigned to #{rayon.actual_user.name}."
         return redirect_to rayons_path
      end
    end
    flash[:success] = "Rayon has been successfully updated."
    return redirect_to rayons_path
  else
    flash[:error] = "Rayon has not been updated."
    return redirect_to :back
  end
end

Answer 1

def update
    rayon = Rayon.find(params[:id])

    unless rayon.update_attributes(params[:rayon])
        flash[:error] = "Rayon not updated."
        return redirect_to :back
    end

    puid = params[:user_id]
    empty = rayon.users.empty?

    if puid == "" or (not empty and rayon.users.last.id.eql?(puid))
        msg = "Rayon updated.",
    else
        msg = "Rayon #{rayon.name} assigned to #{rayon.actual_user.name}.",
        rayon.colporteur_in_rayons.last.update_attributes(
            :until_date => Time.now) unless empty
        Rayon.assign_user(rayon.id, puid)
    end

    flash[:success] = msg[msg_i]
    return redirect_to rayons_path
end

Answer 2

有一个双重密码。所以把它去掉。但是，控制器中有一些业务代码，这些代码不应该在那里。所以我应该重构控制器代码，如下所示：

def update
  rayon = Rayon.find(params[:id])

  if rayon.update_attributes(params[:rayon])
    if params[:user_id] != ""
      rayon.handle_update_user(params[:user_id]
      flash[:success] = "Rayon #{rayon.name} has been succesuly assigned to #{rayon.actual_user.name}."
    else
      flash[:success] = "Rayon has been successfully updated."
    end
    return redirect_to rayons_path
  else
    flash[:error] = "Rayon has not been updated."
    return redirect_to :back
  end
end

控制器方法现在清楚地处理需要采取的操作，并在需要时相应地设置闪存方法。

在人造丝模型中，您可以编写当用户完成更新时需要执行的代码：

class Rayon

  def handle_update_user(user_id)
    if (!users.empty? && users.last.id.eql?(params[:user_id]))
      # do nothing! 
    else 
      colporteur_in_rayons.last.update_attributes(:until_date => Time.now) unless users.empty?
      Rayon.assign_user(rayon.id,params[:user_id])
    end

  end

end

这显然将这些问题分开了。人造丝应该知道当用户更新它时会发生什么(函数的名称可以改进为你真正想要的意思，因为这对我来说并不完全清楚)。它可以更短，但我喜欢明确地写，如果最后一个用户与当前用户相同，则不需要执行任何操作。否则，需要采取行动。如果我没理解错的话。

Answer 3

def update
  rayon = Rayon.find(params[:id])

  unless rayon.update_attributes(params[:rayon])
    flash[:error] = "Rayon has not been updated."
    return redirect_to :back
  end

  if params[:user_id].empty?
    msg = "Rayon has been successfully updated."
  else
    if rayon.users.empty?
      Rayon.assign_user(rayon.id,params[:user_id])
      msg = "Rayon #{rayon.name} has been successfully assigned to #{rayon.actual_user.name}."
    elsif not rayon.users.last.id.eql?(params[:user_id])
      rayon.colporteur_in_rayons.last.update_attributes(:until_date => Time.now)
      Rayon.assign_user(rayon.id,params[:user_id])
      msg = "Rayon #{rayon.name} has been succesuly assigned to #{rayon.actual_user.name}."
    end
  end
  flash[:success] = msg
  return redirect_to rayons_path
end