Nested Associations

[mrsutter]

Hi, I've tried to move my project from 0-9-3 to 0-10-0 and found that version 0.10 doesn't support nested associations.

class AppSerializer < ActiveModel::Serializer
  has_one :user, serializer: UserSerializer
end

class UserSerializer < ActiveModel::Serializer
  has_one :address, serializer: AddressSerializer
  has_one :account, serializer: AccountSerializer
  has_many :devices
  attributes :id, :login
end

In my controller i have

render json: @app

and the response is

{ user: {id: 1, login: "smb@email.com} }

Cause json adapter, takes into consideration only attributes of association, but not nested associations of user.

        serializer.each_association do |name, association, opts|
          if association.respond_to?(:each)
            array_serializer = association
            @hash[name] = array_serializer.map do |item|
              cache_check(item) do
                item.attributes(opts)
              end
            end
          else
            if association && association.object
              @hash[name] = cache_check(association) do
                association.attributes(options)
              end
            elsif opts[:virtual_value]
              @hash[name] = opts[:virtual_value]
            else
              @hash[name] = nil
            end
          end
        end

[joaomdmoura]

Hey @mrsutter, indeed 0.10.x right now does not support nested association, but that is something we look forward to! It's mandatory to 0.10.x release and I mention it on the Future of AMS article.
You can make nested association using json-api and include, but would be just a workaround that might not suit you if you don't want to follow json-api conventions.

[johnnagro]

+1 same experience in my testing of 0.10.0.rc2

[johnnagro]

@mrsutter interesting: #1073 and: #921

[joaomdmoura]

So just updating this thread it seems we are getting close to get it on #1114 cc @johnnagro @mrsutter

[NullVoxPopuli]

resolved by #1127

[malroc]

@joaomdmoura @NullVoxPopuli I'm not sure about this solution. Am I right that we have to specify include: ... every time we need to serialize a nested association?
Isn't it the syntax AMS is supposed to replace? Instead, in the current implementation it is just moved one level deeper.
There was a great convention implemented in 0.8.x branch: if we need to serialize an association, the serializer of the association is called recursively. That was a great, clean, and intuitive approach. I'm not sure why it can't be used in 0.10.x

[malroc]

Also, I can try to implement 0.8.x approach for 0.10.x and send a pull request with the solution, but not sure about the exact dates.

[beauby]

See #1157, #1190.

[beauby]

Nested associations are back, and you can control what exactly will be nested through the include adapter option (#1158, #1127), or simply trust your serializers to choose for you by supplying the include: '**' to the adapter (default is to include only the first level of relationships).

Closing this for now, feel free to reopen if needed.