Api enhancement to support optional collection_class parameter

app/controllers/api/base_controller/parser.rb

@@ -31,17 +31,9 @@ def validate_api_request
       end
 
       def validate_optional_collection_classes
-        @collection_klasses = {}  # Default all to config classes
-        param = params['provider_class']
-        return unless param.present?
-
-        raise BadRequestError, "Unsupported provider_class #{param} specified" if param != "provider"
-        %w(tags policies policy_profiles).each do |cname|
-          if @req.subcollection == cname || @req.expand?(cname)
-            raise BadRequestError, "Management of #{cname} is unsupported for the Provider class"
-          end
-        end
-        @collection_klasses[:providers] = Provider
+        @collection_klasses = {} # Default all to config classes
+        validate_provider_class
+        validate_collection_class
       end
 
       def validate_api_action
@@ -331,6 +323,35 @@ def assert_all_required_fields_exists(data, type, required_fields)
           raise BadRequestError, "Resource #{missing_fields.join(", ")} needs be specified for creating a new #{type}"
         end
       end
+
+      def validate_provider_class
+        param = params['provider_class']
+        return unless param.present?
+
+        raise BadRequestError, "Unsupported provider_class #{param} specified" if param != "provider"
+        %w(tags policies policy_profiles).each do |cname|
+          if @req.subcollection == cname || @req.expand?(cname)
+            raise BadRequestError, "Management of #{cname} is unsupported for the Provider class"
+          end
+        end
+        @collection_klasses[:providers] = Provider
+      end
+
+      def validate_collection_class
+        param = params['collection_class']
+        return unless param.present?
+
+        klass = collection_class(@req.collection)
+        return if param == klass.name
+
+        param_klass = klass.descendants.detect { |sub_klass| param == sub_klass.name }
+        if param_klass.present?
+          @collection_klasses[@req.collection.to_sym] = param_klass
+          return
+        end
+
+        raise BadRequestError, "Invalid collection_class #{param} specified for the #{@req.collection} collection"
+      end
     end
   end
 end

spec/requests/api/querying_spec.rb

@@ -706,4 +706,44 @@ def create_vms_by_name(names)
       expect(response.headers['Access-Control-Allow-Methods']).to include('OPTIONS')
     end
   end
+
+  describe "with optional collection_class" do
+    before { api_basic_authorize collection_action_identifier(:vms, :read, :get) }
+
+    it "fail with invalid collection_class specified" do
+      run_get vms_url, :collection_class => "BogusClass"
+
+      expect_bad_request("Invalid collection_class BogusClass specified for the vms collection")
+    end
+
+    it "succeed with collection_class matching the collection class" do
+      create_vms_by_name(%w(aa bb))
+
+      run_get vms_url, :collection_class => "Vm"
+
+      expect_query_result(:vms, 2, 2)
+    end
+
+    it "succeed with collection_class matching the collection class and returns subclassed resources" do
+      FactoryGirl.create(:vm_vmware, :name => "aa")
+      FactoryGirl.create(:vm_vmware_cloud, :name => "bb")
+      FactoryGirl.create(:vm_vmware_cloud, :name => "cc")
+
+      run_get vms_url, :expand => "resources", :collection_class => "Vm"
+
+      expect_query_result(:vms, 3, 3)
+      expect(response.parsed_body["resources"].collect { |vm| vm["name"] }).to match_array(%w(aa bb cc))
+    end
+
+    it "succeed with collection_class and only returns subclassed resources" do
+      FactoryGirl.create(:vm_vmware, :name => "aa")
+      FactoryGirl.create(:vm_vmware_cloud, :name => "bb")
+      vmcc = FactoryGirl.create(:vm_vmware_cloud, :name => "cc")
+
+      run_get vms_url, :expand => "resources", :collection_class => vmcc.class.name
+
+      expect_query_result(:vms, 2, 2)
+      expect(response.parsed_body["resources"].collect { |vm| vm["name"] }).to match_array(%w(bb cc))
+    end
+  end
 end

tools/rest_api.rb

@@ -47,7 +47,7 @@ class Cli
     API_PARAMETERS       = %w(expand hide attributes decorators limit offset
                               depth search_options
                               sort_by sort_order sort_options
-                              filter by_tag provider_class requester_type).freeze
+                              filter by_tag provider_class collection_class requester_type).freeze
 
     MULTI_PARAMS         = %w(filter).freeze