ruby-on-rails - Rails 如何按嵌套哈希分组

Question

我不知道如何解决这个问题。我在一个名为 data 的 array 中得到了一个 nested hash。这是它的结构。

data = 
[
     {
              :id => 1,
            :name => "S1",
        :children => [
            {
                      :id => 10,
                    :name => "S10",
                :children => [
                    {
                          :id => 20,
                        :name => "S20"
                    }
                ]
            }
        ]
    },
     {
              :id => 1,
            :name => "S1",
        :children => [
           {
                      :id => 10,
                    :name => "S10",
                :children => [
                   {
                          :id => 21,
                        :name => "S21"
                    }
                ]
            }
        ]
    },
     {
              :id => 1,
            :name => "S1",
        :children => [
             {
                      :id => 11,
                    :name => "S11",
                :children => [
                     {
                          :id => 22,
                        :name => "S22"
                    }
                ]
            }
        ]
    }
]

如您所见，在第一层或第二层中有一堆具有相同 id 的元素，因此我需要对它们进行分组。

希望是这样的结果

result=  
[
     {
              :id => 1,
            :name => "S1",
        :children => [
            {
                      :id => 10,
                    :name => "S10",
                :children => [
                    {
                          :id => 20,
                        :name => "S20"
                    },
                    {
                          :id => 21,
                        :name => "S21"
                    }
                ]
            },
            {
                      :id => 11,
                    :name => "S11",
                :children => [
                     {
                          :id => 22,
                        :name => "S22"
                    }
                ]
            }
        ]
    }
]

我试过类似的东西

data.group_by{|s| s[:id]}

但是，它只会对第一层进行分组，我不知道如何对嵌套结构进行分组。

Answer 1

是的，您需要某种递归方法来递归组合和分组嵌套的子项。

这会产生你想要的结果:

def group(data)
  r = {}
  # Combine the children
  data.each do |d| 
    if r[d[:id]]
      r[d[:id]][:children] += d[:children]
    else
      r[d[:id]] = d
    end
  end
  # Now group the children
  r.values.map do |d|
    d[:children] = group(d[:children]) if d[:children]
    d
  end
end