使用ruby从物化路径构建树结构时遇到问题。
假设我有一个排序结果集(来自couchdb):
[
{ :key => [], :value => "Home" },
{ :key => ["about"], :value => "About" },
{ :key => ["services"], :value => "Services" },
{ :key => ["services", "plans"], :value => "Plans" },
{ :key => ["services", "training"], :value => "Training" },
{ :key => ["services", "training", "python"], :value => "Python" },
{ :key => ["services", "training", "ruby"], :value => "Ruby" }
]
我只需要将它作为ruby中的树,以下哈希就足够了:
{ :title => "Home", :path => [], :children => [
{ :title => "About", :path => ["about"] },
{ :title => "Services", :path => ["services"], :children => [
{ :title => "Plans", :path => ["services", "plans"] }
]}
]}
有人可以帮助我吗?
答案 0 :(得分:4)
您需要一个简单的帮助程序类和一点递归:
class Tree
attr_reader :root
def initialize
@root = { :title => 'Home', :path => [ ], :children => [ ] }
end
def add(p)
r_add(@root, p[:key].dup, p[:value])
self
end
private
def r_add(h, path, value)
if(path.empty?)
h[:title] = value
return
end
p = path.shift
c = h[:children].find { |c| c[:path].last == p }
if(!c)
c = { :title => nil, :path => h[:path].dup.push(p), :children => [ ] }
h[:children].push(c)
end
r_add(c, path, value)
end
end
然后:
t = a.inject(Tree.new) { |t, h| t.add(h) }
h = t.root
会在h
中提供此内容:
{:title =>"Home", :path=>[], :children=>[
{:title=>"About", :path=>["about"], :children=>[]},
{:title=>"Services", :path=>["services"], :children=>[
{:title=>"Plans", :path=>["services", "plans"], :children=>[]},
{:title=>"Training", :path=>["services", "training"], :children=>[
{:title=>"Python", :path=>["services", "training", "python"], :children=>[]},
{:title=>"Ruby", :path=>["services", "training", "ruby"], :children=>[]}
]}
]}
]}
如果重要,可以整理空:children
。