A monkey patch to ActiveModel::Serializers 0.9.0.alpha1 to add contextual awareness of nesting and listing.

ams-nested-listed-predicates-monkeypatch.rb

require 'active_model/serializer/associations'
module ActiveModel
  class Serializer
    
    def initialize(object, options={})
      @object        = object
      @scope         = options[:scope]
      @root          = options.fetch(:root, self.class._root)
      @meta_key      = options[:meta_key] || :meta
      @meta          = options[@meta_key]
      @wrap_in_array = options[:_wrap_in_array]
      @only          = Array(options[:only]) if options[:only]
      @except        = Array(options[:except]) if options[:except]
      @key_format    = options[:key_format]
    
    # Watch for predicate options.
      @associated = options[:associated] || false
      @listed = options[:listed] || false
    end
    
    def listed?
      @listed
    end

    def associated?
      @associated
    end

    def nested?
      listed? or associated?
    end
    
    class Association

    # Force all objects serialized as an association
    #  to recognize they're nested.
      def build_serializer(object, options = {})
        serializer_class(object).new(object, options.merge(self.options).merge(associated: true))
      end
    end
  end
end

require 'active_model/array_serializer'
module ActiveModel
  class ArraySerializer

  # Force all objects serialized as an array
  #  to recognize they're listed.
    def serializer_for(item)
      serializer_class = @each_serializer || Serializer.serializer_for(item) || DefaultSerializer
      serializer_class.new(item, scope: scope, listed: true)
    end

  end
end