acts_as_commentable_with_threading - "build_from" method failing?

Question

In my comments controller, I have the following

class CommentsController < ApplicationController

  def create
    @comment_hash = params[:comment]
    #@comment = comment.new(comment_params)
    @obj = @comment_hash[:commentable_type].constantize.find(@comment_hash[:commentable_id])    
    @comment = Comment.build_from(@obj, current_user.id, @comment_hash[:body])
    binding.pry
    #...

At the point where binding.pry is,

@comments_hash is

{"body=>"asdf comment body",
 "commentable_type"=>"Hack",
 "commentable_id"=>"2"}

@obj is

#<Hack id: 2, created_at: "2014-09-16 00:00:00",
updated_at: "2014-09-16 00:00:00", 
body: "some text", 
user_id: 1, 
comment_threads_count: 0>

But @comment outputs

#<Comment id: nil, 
commentable_id: 2, 
commentable_type: "Hack", 
title: nil, body: "asdf, 
comment body", 
subject: nil, 
user_id: 1, 
parent_id: nil, 
lfg: nil, rgt: 
nil, created_at: nil, 
updated_at: nil>

Why are so many things nil here? All my arguments for the build_from method are identical to before, when the code worked properly.

The terminal output when attempting to call @comment.save is

undefined method 'user' for #<Comment:0x5d1b1b0>

I'm not sure what this means. I have a user_id association. I don't see a user param in my params hash.

Any help would be much appreciated.

Answer 1

@Substantial Your suspicion was correct.

Even though I the associations set up via the acts_as_commentable_with_threading method, I still had to do a has_many belongs_to association between the user and the comment. Once I added the has_many belongs_to relationship, things worked out. (and when I removed it again, it stopped working).

having acts_as_commentable_with_threading in the user model is for posting comments on the user, not specifying that the comment belongs to the user. So if you want to post comments on users, you need both that method, AND has_many :comments & belongs_to :user in the comment model

If you want just comments on another model, put the method in that model, and put has_many :comments in the user model, and belongs_to :user in the comment model