Property renamed with :from is not set

[chrisupb]

My user model has the property :password_confirmation and includes the UserRepresenter.

My UserRepresenter defines

property :password_confirmation, :from => :passwordConfirmation

I do a POST with HTTP body:
{
"passwordConfirmation":"123"
}

My controller:

def create
 @user = User.new.from_json(request.raw_post)
 puts @user.password_confirmation # =====> ""
 puts @user.passwordConfirmation  # ==== => "123"
end

Why is password_confirmation not set?

[apotonick]

Looks like a bug, but can you double-check if you're up-to-date, etc? Please write a provoking test, but check this first: https://github.com/apotonick/representable/blob/master/test/json_test.rb#L263

[chrisupb]

What I could find out: This is a Mongoid issue!
If I don't include the representer but extend the class it's working.

Another interesting fact: I include several Mongoid classes in my user class.

class User
 include Roar::Representer
 include UserRepresenter
 include Mongoid::Document
 include Mongoid::Paranoia
 include Mongoid::Timestamps
 include Mongoid::Slug

If I don't include the Representer BEFORE the Mongoid includes:
=> wrong number of arguments (0 for 1)

representable (1.0.1) lib/representable.rb:124:in `collection'
mongoid (2.4.0) lib/mongoid/contexts/mongo.rb:8:in `collection'
mongoid (2.4.0) lib/mongoid/contexts/mongo.rb:93:in `count'
mongoid (2.4.0) lib/mongoid/criteria.rb:155:in `exists?'
mongoid (2.4.0) lib/mongoid/validations/uniqueness.rb:68:in `validate_each'
activemodel (3.1.0) lib/active_model/validator.rb:153:in `block in validate'
activemodel (3.1.0) lib/active_model/validator.rb:150:in `each'

But I gotta sleep now...

[apotonick]

Well, then Mongoid overwrites the #collection class method. Solution: Don't include the representer module but extend your objects at runtime, this doesn't pollute your class.

[chrisupb]

It's not an general issue, as if you only include Mongoid::Document its working.

I will close this issue for now and perhaps write about a solution later.

[chrisupb]

Hmm, it's getting worse with Mongoid. I removed all Roar includes from my model classes as my PolymorphicExtender test seems to work now, but then extending embedded objects doesn't work:

class User
include Mongoid::Document
  embeds_one :profile, :class_name => "Users::Profile"
end

class Users::Profile
include Mongoid::Document
  field :name
end    

user = User.find(id)
respond_with user.profile.extend(ProfileRepresenter)

Extending fails with undefined method `representable_attrs' for Users::Profile:Class

[apotonick]

Paste your ProfileRepresenter!

[chrisupb]

Nothing special :)

module ProfileRepresenter
   include Roar::Representer::JSON

   property :name
end

[apotonick]

@chrisupb Are you sure you updated both Roar and representable to the latest version?

[chrisupb]

Yeah I double checked it. OK I use roar-rails but it fetches
roar 0.9.1
representable 1.0.1
roar-rails (0.0.2)

No change If I use my local repos for the 3 projects.

I already came up against this problem when I first used roar one month ago. But I could fix it by including roar stuff in my models.

I think this is a hint, that extending doesn't work:
https://github.com/apotonick/representable/blob/master/lib/representable.rb#L39 (notice the puts)

  def self.extended(object)

    attrs = representable_attrs
    object.instance_eval do
      @representable_attrs = attrs
    end
    puts object.representable_attrs
  end

Error for nested profile: undefined method `representable_attrs' for #Users::Profile:0x000000050a8ac0

"Error" for normal property: private method `representable_attrs' called for #User:0x00000004913058

So an User IS extended but not the embedded profile.

[apotonick]

Ah, ok if you have nested objects that need a separate representer you have to use the :extend option: http://nicksda.apotomo.de/2011/12/ruby-on-rest-2-representers-and-the-dci-pattern/

Does that help?

[chrisupb]

No because with "nested" I mean Mongoid embedded in this context.
I ONLY use this simple ProfileRepresenter but for extending an in an user embedded profile class

[apotonick]

OOoook, now I get it. Can you provide a minimal app setup so I can investigate that - seems like a misunderstanding between Mongoid and Representable, maybe the #profile method doesn't return a real Profile object but some proxy or something. Thx!

[chrisupb]

Here it is: https://github.com/chrisupb/mongoid-sample
See README
Thank you!

[chrisupb]

I reopen this one, as it's really a show blocker for me.

[apotonick]

Fixed in trailblazer/representable@b7eceac (1.1.1). Some strange mongoid issue that wouldn't let us set instance variables. Was ugly code anyway, so, thanks :-D Also thanks for providing a minimal example, I could very easily setup a test and fix it: trailblazer/representable@b7eceac#diff-2

[chrisupb]

Awesome!! Thank you. This is working now without including anything into the models.

Unfortunately URL helpers are no longer available in the embedded class (instrument) undefined local variable or method `artists_url' for #<Artists::Instrument:0x00000001c16000

I updated my mongoid-example for this problem but did not yet examine it.