+@cache_until_start
+@csrf_exempt
+def start(request, submission_id, key):
+ state = CompetitionState.get_state()
+ if state in (CompetitionState.BEFORE, CompetitionState.AFTER):
+ return globals()['form_' + state](request, submission_id, key)
+
+ submission = get_submission(submission_id)
+ if submission.key != key:
+ return render(request, 'wtem/key_not_found.html')
+
+ submission.opened_link = True
+ submission.save()
+
+ i, exercise = submission.current_exercise()
+ if not exercise:
+ return render(request, 'wtem/thanks_single.html')
+
+ return render(request, 'wtem/start.html', {'exercise_count': len(exercises), 'submission': submission})
+
+