简单总结一下用法 是对 1.3 版本做的
第一步增加 gem
gem 'ancestry'
第二步对模型增加 ancestry:string 字段
bundle
rails g migration add_ancestry_to_categories ancestry:string
rake db:migrate
修改 migration.rb
class AddAncestryToCategories < ActiveRecord::Migration
def self.up
add_column :messages, :ancestry, :string
add_index :messages, :ancestry
end
def self.down
remove_index :messages, :ancestry
remove_column :messages, :ancestry
end
end
第三步修改 model
class Category < ActiveRecord::Base
attr_accessible :desc, :name ,:parent
has_ancestry
end
注意：增加:parent 和 has_ancestry 这步是别的教程里没有强调的
第四步 测试
require 'test_helper'
class CategoryTest < ActiveSupport::TestCase
# test "the truth" do
# assert true
# end
test "dump category" do
@b = Category.create! :name => 'bbbbb', :parent => Category.create!(:name => 'aaaaaaaaa')
@d = Category.create! :name => 'dddddddd', :parent => @b
@e = Category.create! :name => 'eeeeeee', :parent => @d
@c = Category.find_by_name 'bbbbb'
# ap @d
# ap @d.parent
# ap @d.root
ap @d.subtree_ids
# ap @c.parent
# parent Returns the parent of the record, nil for a root node
# parent_id Returns the id of the parent of the record, nil for a root node
# root Returns the root of the tree the record is in, self for a root node
# root_id Returns the id of the root of the tree the record is in
# is_root? Returns true if the record is a root node, false otherwise
# ancestor_ids Returns a list of ancestor ids, starting with the root id and ending with the parent id
# ancestors Scopes the model on ancestors of the record
# path_ids Returns a list the path ids, starting with the root id and ending with the node's own id
# path Scopes model on path records of the record
# children Scopes the model on children of the record
# child_ids Returns a list of child ids
# has_children? Returns true if the record has any children, false otherwise
# is_childless? Returns true is the record has no childen, false otherwise
# siblings Scopes the model on siblings of the record, the record itself is included
# sibling_ids Returns a list of sibling ids
# has_siblings? Returns true if the record's parent has more than one child
# is_only_child? Returns true if the record is the only child of its parent
# descendants Scopes the model on direct and indirect children of the record
# descendant_ids Returns a list of a descendant ids
# subtree Scopes the model on descendants and itself
# subtree_ids Returns a list of all ids in the record's subtree
# depth Return the depth of the node, root nodes are at depth 0
end
end
说明:ap 是 awesome_print
在 rails console 中执行
rake test
需要什么方法尽可在官方的文档里找，整体看还比较完善
