Cache groups before submissions page load

src/main/java/nl/tudelft/submit/controller/AssignmentController.java

@@ -34,6 +34,7 @@ import nl.tudelft.labracore.api.dto.*;
 import nl.tudelft.labracore.lib.security.user.AuthenticatedPerson;
 import nl.tudelft.labracore.lib.security.user.Person;
 import nl.tudelft.librador.dto.view.View;
+import nl.tudelft.submit.cache.StudentGroupCacheManager;
 import nl.tudelft.submit.csv.CSVService;
 import nl.tudelft.submit.dto.create.SubmitAssignmentCreateDTO;
 import nl.tudelft.submit.dto.create.VersionCreateDTO;
@@ -64,6 +65,9 @@ import com.opencsv.exceptions.CsvValidationException;
 @Controller
 public class AssignmentController {
 
+	@Autowired
+	private StudentGroupCacheManager groupCache;
+
 	@Autowired
 	private AssignmentService assignmentService;
 
@@ -183,6 +187,8 @@ public class AssignmentController {
 		model.addAttribute("grades", submissions.stream()
 				.flatMap(s -> s.getGrades().stream())
 				.collect(Collectors.toMap(GradeSummaryDTO::getId, Function.identity())));
+		model.addAttribute("groups",
+				groupCache.get(submissions.stream().map(s -> s.getGroup().getId()).distinct()));
 		return "assignment/submissions";
 	}