Rails Ancestry gem:保存节点时确保父节点存在

时间:2014-09-28 00:40:31

标签: ruby-on-rails ruby ancestry

我今天第一次尝试the Ancestry gem作为内容管理系统的一部分,并且希望能够手动创建节点并将它们连接在一起。换句话说,上下文没有规定任何新节点的父节点是什么,不像每个人都读过的许多线程讨论示例。

目前,当我尝试保存(创建或更新)具有不存在的parent_id(“4”)的节点时,我收到错误:

ActiveRecord::RecordNotFound in TreesController#update
Couldn't find Tree with 'id'=4

我希望将任何引用不存在的父节点的节点分配给没有父节点。我该怎么做?

这是trees_controller.rb的相关部分:

  def create
    @tree = Tree.new(tree_params)
    if @tree.save
        redirect_to trees_url, notice: "Tree was successfully created"
    else
        render :new
    end     
  end

  ...

  private

  def tree_params
    params.require(:tree).permit(:name, :value, :note, :parent_id)
  end

由于

1 个答案:

答案 0 :(得分:0)

经过一周的研究,我设法对它进行了分类。对于那些遇到同样障碍的人来说,这是一个解决方案:

  def create
    parent_exists = Tree.exists?(params[:tree][:parent_id])
    if !parent_exists
        params[:tree][:parent_id] = nil
        note = "Parent node didn't exist so set to nil."
    end
    @tree = Tree.new(tree_params)
    if @tree.save
        redirect_to trees_url, notice: "Node was successfully created. " + note.to_s
    else
        render :new, notice: "There was an error saving this node. Please try again."
    end
  end