CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-4
marcamillion
marcamillion

Reputation: 33755

How do I create an association that has other associations in a Rails way?

So I have a Node, Video, FamilyTree and User.

When you are logged in as a current_user, they can upload a video. Whenever a video is uploaded, it becomes a node on the current_user's family_tree.

The main association is: Video has_one Node.

This works:

@video.create_node(name: @video.title, family_tree_id: @family_tree.id, user_id: current_user.id)

However, per the Rails Guides, I should be able to do something like this:

@video.create_node(@family_tree.attributes)

That doesn't exactly work, because it assigns the family_tree.name to node.name which is not correct (as you can see from my correct example above).

I tried something like this:

@video.create_node(@video.attributes, @family_tree.attributes, current_user.attributes)

But that didn't work.

How do I do this in a more elegant Rails way?

Upvotes: 0

Views: 28

Answers (2)

numbers1311407
numbers1311407

Reputation: 34072

Apart from passing associations by name and not key (user vs user_id, etc), this is already about as railsy as you get.

Rails has its share of magic but I don't think there's anything about creating one record out of the attributes of another as in your example.

End result would look something like:

@video.create_node(
  name: @video.title, 
  family_tree: @family_tree, 
  user: current_user
)

Upvotes: 2

Matt Stevens
Matt Stevens

Reputation: 1124

@numbers... is correct, you have to name the specific attributes in order for rails to know which attributes you mean. So your first example is correct, the second is flawed.

However there is another option, you can create another method called (for example) create_node_on_video, accept both of the models video and family-tree and within this helper method method pick out and save the elements needed using create_node.

def create_node_on_video
  return if @video.nil? or @family-tree.nil?
  @video.create_node(name: @video.title, family_tree_id: @family_tree.id, user_id: current_user.id)
end

Upvotes: 1

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