Ruby on Rails的 - 造型有向图

Question

我想有向图我的Ruby on Rails应用程序 我有两个型号，标签和连接

class Connection < ActiveRecord::Base 
    attr_accessible :cost, :from_id, :to_id 
    belongs_to :from_tag, :foreign_key => "from_id", :class_name => "Tag" 
    belongs_to :to_tag, :foreign_key => "to_id", :class_name => "Tag" 
    end 



class Tag < ActiveRecord::Base 
    attr_accessible :location_info, :reference 
    has_many :to_connections, :foreign_key => 'from_id', :class_name => 'Connection' 
    has_many :to_tags, :through => :to_connections 
    has_many :from_connections, :foreign_key => 'to_id', :class_name => 'Connection' 
    has_many :from_tags, :through => :from_connections 
    end 

当我创建一个标签，像这样

模型

a = Tag.create(:reference => "a", :location_info => "Tag A") 
b = Tag.create(:reference => "b", :location_info => "Tag B") 

它工作正常。

但是，当我试图让这两个

Connection.create(:from_tag => a, :to_tag => b, :cost => 5) 

之间的连接，我得到一个错误说

“::加载ActiveModel :: MassAssignmentSecurity错误：无法大规模指派保护的属性： from_tag和to_tag“

，任何人都可以看到问题吗？

Answer 1

您无法批量分配关系。

http://api.rubyonrails.org/classes/ActiveModel/MassAssignmentSecurity/ClassMethods.html

connection = Connection.new 
connection.from_tag = a 
connection.to_tag = b 
connection.cost = 5 
connection.save