How to solve the `Object doesn't support #inspect` error?

Question

I am using rails v3.2.2 and I get a strange error when I try to load associated records.

The following is the Terminal input/output I get:

1.9.2-p318         


        

Answer 1

There are two constants called Article on your app. One is your active record class, top level constant. The other is the module Category::Article.

When you do belongs_to :article, it would seem that rails starts looking for an Article constant in the class the belongs_to is called from so it is finding the wrong one. This causes all sorts of mess, since you obviously can't use an activerecord class and a module interchangeably

Setting :class_name => '::Article' forces the top level Article class to be found instead.

Answer 2

The problem seems to be solved by stating the following in my Category::Article::ArticleRelationship:

class Category::Article::ArticleRelationship < ActiveRecord::Base
  belongs_to :article,
    :class_name    => '::Article', # note I added '::'
    :foreign_key   => 'article_id'
end

but I didn't understand why?

Answer 3

If are using rails 4, the problem came from protected_attributes gem, u need to upgrade the gem version 1.0.3 to 1.0.5, then it will work.