[SOLVED] Rails 3.1.3 REST : Can't retrieve errors from activeresource side (json serializer)

Rails 3.1.3 REST : Can't retrieve errors from activeresource side (json serializer)

I have Server working with active models (not active record), and client side with activeresource .

For example server side controller have such code

...
      def update

        if @supplier.update_attributes(params[:supplier])
           respond_to do |format|
              format.any  { head :ok }
            end
        else

          respond_with(@supplier.errors,:status => :unprocessable_entity)
        end    
      end
...

Active model has next code

...
     class Subscriber < BaseModel
     include ActiveModel::Validations  
     include ActiveModel::Serialization  
     include ActiveModel::Callbacks  
     extend ActiveModel::Naming
     validates :email,  :format =>   /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i  
     def update_attributes(attributes={})
         self.attributes.merge!(attributes)
         self.save
      end   

      def save
          if self.valid?
            super
          else
            false
          end    
      end   
...

I type next code from rails console of client application

 s = Supplier.find(13)
 s.email = ''
 s.save

return false because of invalid email

this is errors object from server before sending with respond_with

#<ActiveModel::Errors:0x000001012e9d78 @base=#<Supplier:0x000001032bf8c8 @attributes={:id=>13, :company_name=>.......}, @validation_context=nil, @errors=#<ActiveModel::Errors:0x000001012e9d78 ...>>, @messages={:email=>["is invalid"]}>

and client has next values of s

   .... @remote_errors=#<ActiveResource::ResourceInvalid: Failed.  Response code = 422.  Response message = .>, @validation_context=nil, @errors=#<ActiveResource::Errors:0x000001034991d0 @base=#<Supplier:0x000001034af048 ...>, @messages={}>>

Why I can't take errors in client side (messages is empty hash)?

UPD: client get {} in body of response

"--- !ruby/object:Net::HTTPClientError \nbody: \"{}\"\nbody_exist: true\ncode: \"422\"\nheader: \n  content-type: \n  - application/json; charset=utf-8\n  x-ua-compatible: \n  - IE=Edge\n  cache-control: \n  - no-cache\n  x-runtime: \n  - \"0.128106\"\n  content-length: \n  - \"2\"\n  server: \n  - WEBrick/1.3.1 (Ruby/1.9.2/2011-02-18)\n  date: \n  - Thu, 29 Dec 2011 10:57:50 GMT\n  connection: \n  - close\n  set-cookie: \n  - _api_session=BAh7BkkiD3Nlc3Npb25faWQGOgZFRkkiJTM5OWQwNTZhMzI1MzcxYzdjZGI2NzNkZWZjNWE0OTQwBjsAVA%3D%3D--b9a0f65001dd994f269800f1c56259523ab669b1; path=/; HttpOnly\nhttp_version: \"1.1\"\nmessage: \"\"\nread: true\nsocket: \n"

UPD2 if controller action looks next

 @supplier.update_attributes(params[:supplier])
 respond_with(@supplier)

than response looks next

"--- !ruby/object:Net::HTTPClientError \nbody: \"{\\\"email\\\":[\\\"is invalid\\\"]}\"\nbody_exist: true\ncode: \"422\"\nheader: \n...

so I think problem is that client and server use different logic for serialization

  class Errors < ActiveModel::Errors

   # Grabs errors from a json response.
    def from_json(json, save_cache = false)
      array = Array.wrap(ActiveSupport::JSON.decode(json)['errors']) rescue []
      from_array array, save_cache
    end

client expects server uses errors key for errors hash ({:errors=>{:email=>["is invalid"]}}) but server doesn't!!(just {:email=>["is invalid"]})

What I miss ???

Solution