justin-lu / acts_as_associate_tree

organize a tree data

支持你通过方法生成tree 数据

class Foo
  attr_reader :i
  def initialize(i)
    @i = i
  end

  def items
    foo_items = []
    i.times do |i|
      foo_items.push Foo.new("Item" + i.to_s)
    end
    foo_items
  end

  class << self
    def all
      all_foos = []
      2.times do |i|
        all_foos.push Foo.new(i + 1)
      end
      all_foos
    end
  end
end

generate_tree_nodes do
  nodes { Foo.all }
  node_attrs { { :text => i } } # invoke this block by the instance_eval
                                # method of each element in nodes
  children {
    nodes { items }
    node_attrs { { :text => i } } # using nodes#element.instance_eval to run this block
  }
end

通过generate_tree_nodes这个接口，可以生成以下数据

[{
  :text=>1,
  :children=>[{
    :text=>"Item0",
    :leaf=>true
  }]
}, {
  :text=>2,
  :children=>[{
    :text=>"Item0",
    :leaf=>true
  }, {
    :text=>"Item1",
    :leaf=>true
  }]
}]

通过在application_controller或者model添加include ActsAsAssociateTree，然后就可以通过以下关系，快速构建你的tree了。

class Parent < ActiveRecord::Base
   has_many :children
end

class Child < ActiveRecord::Base
  belongs_to :parent
end

其数据如下:

 # Parent.all
 # +-------+---------+
 # | id    | name    |
 # +-------+---------+
 # | 1     | xx1     |
 # | 2     | xx2     |
 # | 3     | xx3     |
 # | 4     | xx4     |
 # | 5     | xx5     |
 # +-------+---------+
 
 # Child.all
 # +-------+--------------+--------+
 # | id    | parent_id    | name   |
 # +-------+--------------+--------+
 # | 1     | 1            | xx0    |
 # | 2     | 1            | xx1    |
 # | 3     | 1            | xx2    |
 # | 4     | 2            | xx0    |
 # | 5     | 2            | xx1    |
 # +-------+--------------+--------+

class ParentController < ApplicationController
  include ActsAsAssociateTree
  
  # GET /parent/index_tree.json
  def index_tree
    special_tag = 'special_tag'
    render :josn => generate_tree_nodes {
      # 一个树可以有不同的结点集
      add_set {
        nodes { Parent.all }  # 结点的数据，block的执行结果需返回一个数组
        node_attrs { { :name => name } }  # 结点属性，block执行结果需返回一个Hash实例，block 中可以执行任何一个 Parent 实例能执行的方法
        children { 
          nodes { children }  # 在子结点中可以执行任何一个 Parent 实例能执行的方法
          node_attrs { { :name => name, :special => id == 1 ? special_tag : 'nothing' } }  # 每一个 block 中都能访问闭包变量，如 special_tag
        }
        # 可以添加多个子节点
        children {
          nodes { [1, 2, 3, 4, 5] }
          node_attrs { { :name => self } }
        }
      }
      # 其他结点集
      add_set {
        set_attrs { { :text => 'i am a tree nodes set' } }  # 可以添加结点集描述
        nodes { %w(act_as_associate_tree is so powerful) }
        node_attrs { { :text => self } }
      }
    }
  end
end

index_tree 方法会返回如下形式的数据

[{:name=>"xx1",
  :children=>
   [{:name=>"xx0", :special=>"special_tag", :leaf=>true},
    {:name=>"xx1", :special=>"nothing", :leaf=>true},
    {:name=>"xx2", :special=>"nothing", :leaf=>true},
    {:name=>1, :leaf=>true},
    {:name=>2, :leaf=>true},
    {:name=>3, :leaf=>true},
    {:name=>4, :leaf=>true},
    {:name=>5, :leaf=>true}]},
 {:name=>"xx2",
  :children=>
   [{:name=>"xx0", :special=>"nothing", :leaf=>true},
    {:name=>"xx1", :special=>"nothing", :leaf=>true},
    {:name=>1, :leaf=>true},
    {:name=>2, :leaf=>true},
    {:name=>3, :leaf=>true},
    {:name=>4, :leaf=>true},
    {:name=>5, :leaf=>true}]},
 {:name=>"xx3",
  :children=>
   [{:name=>1, :leaf=>true},
    {:name=>2, :leaf=>true},
    {:name=>3, :leaf=>true},
    {:name=>4, :leaf=>true},
    {:name=>5, :leaf=>true}]},
 {:name=>"xx4",
  :children=>
   [{:name=>1, :leaf=>true},
    {:name=>2, :leaf=>true},
    {:name=>3, :leaf=>true},
    {:name=>4, :leaf=>true},
    {:name=>5, :leaf=>true}]},
 {:name=>"xx5",
  :children=>
   [{:name=>1, :leaf=>true},
    {:name=>2, :leaf=>true},
    {:name=>3, :leaf=>true},
    {:name=>4, :leaf=>true},
    {:name=>5, :leaf=>true}]},
 {:text=>"i am a tree nodes set",
  :children=>
   [{:text=>"act_as_associate_tree", :leaf=>true},
    {:text=>"is", :leaf=>true},
    {:text=>"so", :leaf=>true},
    {:text=>"powerful", :leaf=>true}]}]