Add support for inline serializers

[beauby]

This is the second part of #1193, and is based on top of #1225. This PR allows for defining nested serializers with a block syntax as follows:

class PostSerializer
  attributes ...
  has_many :comments do
    attributes ...
  end
end

[joaomdmoura]

IMO no need for the changelog here, I think we can group it all under a nesting serializer feature entry. 😄

[joaomdmoura]

@beauby could we have a specific docs on how to do nested / namespaced serializers?
Or even some moe specific examples like, "how to verison API using namespaces"

[beauby]

@joaomdmoura Sure, will do!

[NullVoxPopuli]

@beauby did you make the docs per @joaomdmoura 's suggestion? are they in a different pr that I haven't yet gotten to? :-)

[beauby]

@joaomdmoura @NullVoxPopuli So there is an explicit example in the docs about nested serializers. I will eventually write a How To about API versioning with AMS but it is unrelated to this PR. As far as I'm concerned, this PR is ready for merging (squashing apart). Any remarks?

[NullVoxPopuli]

@beauby LGTM :-)

[beauby]

Closing this one for now as we're moving towards using the block syntax for overriding associations rather than specifying nested serializers.

[itsmechlark]

Hi,

I tried to use this feature but association returns all attributes:

module Api
  module V1
    class SectionSerializer < ActiveModel::Serializer
      attributes :id, :name, :short_name

      has_many :libraries do
        attributes :id, :name, :short_name, :code
      end

      belongs_to :parent do
        attributes :id, :name, :short_name
      end

      # TODO: Remove this in the future
      def libraries
        object.products
      end
    end
  end
end

section = Section.first
opts = { serializer: Api::V1::SectionSerializer }
serializable_resource = ActiveModel::SerializableResource.new(section, opts)
serializable_resource.as_json # => {:id=>46, :name=>"Test1", :short_name=>"Test1", :libraries=>[{"id"=>41, "name"=>"test", "short_name"=>"test", "created_at"=>Tue, 20 Oct 2015 11:20:14 UTC +00:00, "updated_at"=>Tue, 20 Oct 2015 11:20:14 UTC +00:00, "config"=>{}, "banner_file_name"=>"12k.png", "banner_content_type"=>"image/png", "banner_file_size"=>12093, "banner_updated_at"=>Tue, 20 Oct 2015 11:19:57 UTC +00:00, "logo_file_name"=>"12k.png", "logo_content_type"=>"image/png", "logo_file_size"=>12093, "logo_updated_at"=>Tue, 20 Oct 2015 11:20:03 UTC +00:00, "rank"=>0, "code"=>"test"}], :parent=>nil} 

[beauby]

@itsmechlark Thanks for your interest. However this feature has not been merged, and will probably not be.
What you can do though is the following:

module Api
  module V1
    class SectionSerializer < ActiveModel::Serializer
      attributes :id, :name, :short_name

      has_many :libraries
      class LibrarySerializer < ActiveModel::Serializer
        attributes :id, :name, :short_name, :code
      end

      belongs_to :parent # Here I'm guessing parent is a Section
      class SectionSerializer < ActiveModel::Serializer
        attributes :id, :name, :short_name
      end

      # TODO: Remove this in the future
      def libraries
        object.products
      end
    end
  end
end

[itsmechlark]

@beauby Thanks for immediate respond. Hope this feature will be added in future, it will help alot. Thanks. BTW, I merge it with my fork repo just to test.

[itsmechlark]

And also, does AMS supports option in associations like has_many to use like:

has_many :libraries, as: :products

[beauby]

@itsmechlark Yes, you can specify the key option, that will set the JSON key under which the association will be serialized.