DataMapper has n through Resource DELETE (Remove from association), does not work

Question

I have two classes,

class User
   include DataMapper::Resource
   property :id, Serial
   property :name, String

   has n :posts, :through => Resource

end

class Post
   include DataMapper::Resource
   property :id, Serial
   property :title, String
   property :body, Text

   has n :users, :through => Resource
end

So, as soon as I get a new message like:

Post.new(:title => "Hello World", :body = "Hi there").save

I'm having serious problems adding and removing from the association, for example:

User.first.posts << Post.first #why do I have to save this as oppose from AR?
(User.first.posts << Post.first).save #this just works if saving the insertion later

And how do I remove a message from this association? I am using the following, but definitely not working:

User.first.posts.delete(Post.first) #returns the Post.first, but nothing happens
User.first.posts.delete(Post.first).save  #returns true, but nothing happens
User.first.posts.delete(Post.first).destroy #destroy the Post.first, not the association

So I really don't know how to remove this from the BoltUser array.

Answer 1

The delete () method and other methods from the array work only in copies of collections in memory. In fact, they do not change anything until you save the objects.

, CRUD, , . , create() destroy(), / , .

, , :

User.first.posts.first(1).destroy

User.first.posts.first(1) , . ( ) .

Answer 2

:

#to add
user_posts = User.first.posts
user_posts << Bolt.first
user_posts.save 

#to remove
user_posts.delete(Bolt.first)
user_posts.save

, - , , , .

AR, .