Fix crash on empty active_assistants

advlabdb/adminModelViews.py

@@ -1391,7 +1391,10 @@ class AnalysisView(SecureAdminBaseView):
 
         if form.validate_on_submit():
             if form.assistant_marks_submit.data:
-                return assistant_marks_analysis(self)
+                ret = assistant_marks_analysis(self)
+
+                if ret is not None:
+                    return ret
 
             if form.final_part_marks_submit.data:
                 return final_part_marks_analysis(self)

advlabdb/analysis.py

@@ -2,6 +2,7 @@ from base64 import b64encode
 from io import BytesIO
 
 import numpy as np
+from flask import flash
 from flask_login import current_user
 from matplotlib.figure import Figure
 from matplotlib.ticker import MaxNLocator
@@ -78,6 +79,10 @@ def mark_hists(markType, active_assistants):
 def assistant_marks_analysis(cls):
     active_assistants = db.session.scalars(select(Assistant).join(User).where(User.active is True)).all()
 
+    if not active_assistants:
+        flash("No active assistants!", "warning")
+        return None
+
     oral_mark_hists = mark_hists("Oral", active_assistants)
     protocol_mark_hists = mark_hists("Protocol", active_assistants)