Ruby on Rails 3 - to_json not including all attributes

Question

I'm using the to_json method on my model object that I created by doing something like:

user = User.find(1)

When I do user.to_json, a lot of attributes are missing, including user.id from the encoded JSON string. It appears that all of the attributes that I've added as attr_accessible from the User model are there, but none of the others. Perhaps that is what to_json is doing, but I think that adding id to attr_accessible is a no go.

What is the right way of solving this problem?

UPDATE

This looks to be a specific issue with Devise. If I comment out the following from user.rb, everything works as expected:

devise :rememberable, :trackable, :token_authenticatable, :omniauthable

Answer 1

I haven't checked but I believe Devise does that for you; it includes only certain attributes via attr_accessible.

In any case the right way to solve this is to override the as_json method like so:

def as_json(options = nil)
  {
    my_attr: my_attr,
    etc: etc
  }
end

It's a simple hash and it's a really powerful method to generate JSON in AR, without messing with the to_json method.

Answer 2

By default Devise overrides the serializable_hash method to expose only accessible attributes (so things like the encrypted_password doesn't get serialized by default on APIs).

You could try to override this method and add the auth_token to the hash, something like this:

def serializable_hash(options = nil) super(options).merge("auth_token" => auth_token) end