ruby-on-rails-3 - 如何从祖先生成json树

Question

我用祖先树成目标树。我想使用json将那棵树的内容发送到浏览器。

我的 Controller 是这样的:

@goals = Goal.arrange
respond_to do |format|
  format.html # index.html.erb
  format.xml  { render :xml => @goals }
  format.json { render :json =>  @goals}
end

当我打开json文件时，得到以下输出:

{"#<Goal:0x7f8664332088>":{"#<Goal:0x7f86643313b8>":{"#<Goal:0x7f8664331048>":{"#<Goal:0x7f8664330c10>":{}},"#<Goal:0x7f8664330e68>":{}},"#<Goal:0x7f86643311b0>":{}},"#<Goal:0x7f8664331f70>":{},"#<Goal:0x7f8664331d18>":{},"#<Goal:0x7f8664331bd8>":{},"#<Goal:0x7f8664331a20>":{},"#<Goal:0x7f86643318e0>":{},"#<Goal:0x7f8664331750>":{},"#<Goal:0x7f8664331548>":{"#<Goal:0x7f8664330aa8>":{}}}

如何在json文件中呈现目标对象的内容？

我已经试过了:

@goals.map! {|goal| {:id => goal.id.to_s}

但这不起作用，因为@goals是有序哈希。

Answer 1

我在https://github.com/stefankroes/ancestry/issues/82上从tejo用户那里得到了一些帮助。

解决方案是将此方法放入目标模型:

def self.json_tree(nodes)
    nodes.map do |node, sub_nodes|
      {:name => node.name, :id => node.id, :children => Goal.json_tree(sub_nodes).compact}
    end
end

然后使 Controller 看起来像这样:

@goals = Goal.arrange
respond_to do |format|
  format.html # index.html.erb
  format.xml  { render :xml => @goals }
  format.json { render :json =>  Goal.json_tree(@goals)}
end