Ruby on rails Rails：优化控制器操作（安全检查）

我在控制器中有一个动作，如下所示：

  def show
    @project = current_customer.projects.where(id: params[:project_id]).first
    if @project
      @feature = @project.features.where(id: params[:feature_id]).first
      if @feature
        @conversation = @feature.conversations.where(id: params[:id]).first
        unless @conversation
          head 401
        end
      else
        head 401
      end
    else
      head 401
    end
  end

---

问题在于头401的重复。有没有更好的方法来写这个动作？

我会这样写

def show
  @project = current_customer.projects.where(id: params[:project_id]).first
  @feature = @project.features.where(id: params[:feature_id]).first if @project
  @conversation = @feature.conversations.where(id: params[:id]).first if @feature

  # error managment
  head 401 unless @conversation      
end

Model Project
  ...
def get_conversation
  feature = features.where(id: params[:feature_id]).first
  conversation = feature.conversations.where(id: params[:id]).first if feature
end

---

我会这样写

def show
  @project = current_customer.projects.where(id: params[:project_id]).first
  @feature = @project.features.where(id: params[:feature_id]).first if @project
  @conversation = @feature.conversations.where(id: params[:id]).first if @feature

  # error managment
  head 401 unless @conversation      
end

Model Project
  ...
def get_conversation
  feature = features.where(id: params[:feature_id]).first
  conversation = feature.conversations.where(id: params[:id]).first if feature
end

---

也许你可以用这样的东西在你的项目模型中重构

def show
  @project = current_customer.projects.where(id: params[:project_id]).first
  @feature = @project.features.where(id: params[:feature_id]).first if @project
  @conversation = @feature.conversations.where(id: params[:id]).first if @feature

  # error managment
  head 401 unless @conversation      
end

Model Project
  ...
def get_conversation
  feature = features.where(id: params[:feature_id]).first
  conversation = feature.conversations.where(id: params[:id]).first if feature
end

在你的控制器里

Controller ProjectController
def show
  @project = current_customer.projects.where(id: params[:project_id]).first
  @conversation = @project.get_conversation

  head 401 unless @conversation
end

---

也许你可以用这样的东西在你的项目模型中重构

def show
  @project = current_customer.projects.where(id: params[:project_id]).first
  @feature = @project.features.where(id: params[:feature_id]).first if @project
  @conversation = @feature.conversations.where(id: params[:id]).first if @feature

  # error managment
  head 401 unless @conversation      
end

Model Project
  ...
def get_conversation
  feature = features.where(id: params[:feature_id]).first
  conversation = feature.conversations.where(id: params[:id]).first if feature
end

在你的控制器里

Controller ProjectController
def show
  @project = current_customer.projects.where(id: params[:project_id]).first
  @conversation = @project.get_conversation

  head 401 unless @conversation
end

---

谢谢你的回答。我还有一个相关的问题，我可以在这个行动中使用CanCan进行错误管理吗？这是个好主意吗？@Alex我从来没用过CanCan，这一点我帮不了你。谢谢你的回答。我还有一个相关的问题，我可以在这个行动中使用CanCan进行错误管理吗？这是个好主意吗？@Alex我从来没用过CanCan，这一次我帮不了你。