TMSS-190: lazy loading of lofar.lta.sip reduces startup time

SAS/TMSS/src/tmss/tmssapp/viewsets/scheduling.py

@@ -35,8 +35,6 @@ from lofar.sas.tmss.tmss.tmssapp.renderers import PlainTextRenderer
 from rest_framework.views import APIView
 from rest_framework.decorators import api_view, renderer_classes
 
-from lofar.sas.tmss.tmss.tmssapp.adapters.sip import generate_sip_for_dataproduct
-
 
 class TextPlainAutoSchema(SwaggerAutoSchema):
     def get_produces(self):
@@ -322,6 +320,7 @@ class DataproductViewSet(LOFARViewSet):
     @action(methods=['get'], detail=True, url_name="sip")
     def sip(self, request, pk=None):
         dataproduct = get_object_or_404(models.Dataproduct, pk=pk)
+        from lofar.sas.tmss.tmss.tmssapp.adapters.sip import generate_sip_for_dataproduct
         return HttpResponse(generate_sip_for_dataproduct(dataproduct).get_prettyxml(), content_type='application/xml')
 
     @swagger_auto_schema(responses={200: 'The SIP graph for this dataproduct',
@@ -331,6 +330,7 @@ class DataproductViewSet(LOFARViewSet):
     def sip_graph(self, request, pk=None):
         dataproduct = get_object_or_404(models.Dataproduct, pk=pk)
         from lofar.lta.sip import visualizer
+        from lofar.sas.tmss.tmss.tmssapp.adapters.sip import generate_sip_for_dataproduct
         return HttpResponse(visualizer.visualize_sip(generate_sip_for_dataproduct(dataproduct)), content_type='image/svg+xml')