如何根据控制器操作 [:create, :update] 使模型回调有条件？

Question

我想在goal.rb

中做这样的事情

  before_save :set_tag_owner,:if => [:create, :update]

  def set_tag_owner
    # Set the owner of some tags based on the current tag_list
    set_owner_tag_list_on(self.user, :tags, self.tag_list)
    self.tag_list = nil
  end

我希望此方法在仅保存 goals_controller.

的创建和更新操作之前起作用

否则我运行会遇到标记问题，当目标被标记为已完成时，标记就会消失，因为 set_tag_owner 将其标记设置为 nil。

  def mark_accomplished
    @goal.update(accomplished: true)
  end

  def create
    @goal = current_user.goals.build(goal_params)
    @goal.save
    respond_modal_with @goal, location: root_path, notice: 'Goal was successfully created! Go chase those dreams!'
  end

  def update
    @goal.update(goal_params)
    respond_modal_with @goal, location: root_path
  end

虽然我需要这一行 self.tag_list = nil 因为没有它标签会被双重渲染

我还尝试通过 before_action 回调在控制器中应用该目标模型逻辑，但即使我将 self 更改为 [=18=，我仍收到 undefined 错误].

Answer 1

另一种方法是添加一个 attr_accessor 到您的模型并使用它来停止 before_save

一个例子

class Goal < ActiveRecord::Base

  attr_accessor :dont_set_tag_owner

  before_save :set_tag_owner, :unless => dont_set_tag_owner

  def set_tag_owner
    # Set the owner of some tags based on the current tag_list
    set_owner_tag_list_on(self.user, :tags, self.tag_list)
    self.tag_list = nil
  end

end

然后，在控制器中

def mark_accomplished
  @goal.update(accomplished: true, :dont_set_tag_owner => true)
end

而且，只是为了给你多一个选择——根据你对updated_at的需要，你也可以这样做

def mark_accomplished
  @goal.update_column(accomplished: true)
end

如何根据控制器操作 [:create, :update] 使模型回调有条件？

How to make a model callback conditional based upon controller actions [:create, :update]?

ruby

tags

model-view-controller

ruby-on-rails

acts-as-taggable-on