gistfile1.js

http://core.ssbe.localhost/clients
{
  "href":       "http://core.ssbe.localhost/clients",
  "item_count": 2,
  "items": [
{
  "_type":       "Client",
  "href":        "http://core.ssbe.localhost/clients/API",
  "id":          "490a167b-c725-49e3-a917-2a5f5a486b4a",
  "name":        "API",

  "parent_href": null,
  "hosts_href":  "http://core.ssbe.localhost/clients/API/hosts",
  "created_at":  "2000-01-01T00:00:00Z",
  "updated_at":  "2000-01-01T00:00:00Z"
}
,
{
  "_type":       "Client",
  "href":        "http://core.ssbe.localhost/clients/legacy_client",
  "id":          "1af03a8f-c708-4891-aa06-c0af27cef740",
  "name":        "legacy_client",
  "parent_href": "http://core.ssbe.localhost/clients/API",
  "hosts_href":  "http://core.ssbe.localhost/clients/legacy_client/hosts",
  "created_at":  "2008-12-02T21:37:39Z",
  "updated_at":  "2008-12-02T21:37:39Z"
}

  ]
}

gistfile3.js

http://core.ssbe.localhost/service_descriptors
{
  "href":  "http://core.ssbe.localhost/service_descriptors",
  "items": [
{
  "_type":        "ServiceDescriptor",
  "href":         "http://core.ssbe.localhost/service_descriptors/kernel",
  "service_type": "http://systemshepherd.com/services/kernel"
}
,
{
  "_type":        "ServiceDescriptor",
  "href":         "http://core.ssbe.localhost/service_descriptors/measurements",
  "service_type": "http://systemshepherd.com/services/measurements"
}
,
{
  "_type":        "ServiceDescriptor",
  "href":         "http://core.localhost/service_descriptors/message_queues",
  "service_type": "http://systemshepherd.com/services/message-queues"
}

  ]
}


http://core.ssbe.localhost/service_descriptors/kernel
{
  "_type"        : "ServiceDescriptor",
  "href"         : "http://core.ssbe.localhost/service_descriptors/kernel",
  "service_type" : "http://systemshepherd.com/services/kernel",
  "items"    : [
    {
      "_type"  : "ResourceDescriptor",
      "name"   : "AllServiceDescriptors",
      "href"   : "http://core.ssbe.localhost/service_descriptors"
    }
,
    {
      "_type"  : "ResourceDescriptor",
      "name"   : "AllClients",
      "href"   : "http://core.ssbe.localhost/clients"
    }
,
/* ... */
  ]
}

model_extensions.rb

module DataMapper
  module SsbeModelExtensions

    # ...

    attr_reader :collection_uri
    def collection(uri, query = {})
      begin
        base_model.instance_variable_set(:@collection_uri, uri)
        repository.read_many(Query.new(self.repository, self)).to_a
      ensure
        base_model.instance_variable_set(:@collection_uri, nil)
      end
    end

  end

  Model.send(:include, SsbeModelExtensions)

end

ssbe_adapter.rb

module DataMapper::Adapters
  class SsbeAdapter
      def read_many(query)
        Collection.new(query) do |collection|

          records = get_collection(query)

          properties = query.fields
          records.each do |record|
            values = properties.map { |p| record[p.name] }
            collection.load(values)
          end
        end
      end

      def get_collection(query) 
        model      = query.model

        resource = collection_resource_for(model)
        response = resource.get

        records = parse_collection(response.body)

        records = query_records(records, query)
      end

      def collection_resource_for(model)
        if uri = model.instance_variable_get(:@collection_uri)
          http.resource(uri, :accept => ServiceIdentifiers[model.service_type].mime_type)
        else
          service_descriptor = service_descriptors[model.service_type]
          resource_descriptor = service_descriptor[model.resource_name]

          resource_descriptor.resource
        end
      end