Moved the check function to the model

ihatemoney/models.py

@@ -752,6 +752,22 @@ class Bill(db.Model):
         else:
             return 0
 
+    def involves_deactivated_members(self, project):
+        """Check whether the bill contains deactivated member.
+        Return:
+        True if it contains deactivated member,
+        False if not.
+        """
+        owers_id = [int(m.id) for m in self.owers]
+        bill_member_id_list = owers_id + [self.payer_id]
+        deactivated_member_number = (
+            Person.query.filter(Person.id.in_(bill_member_id_list))
+            .filter(Person.project_id == project.id)
+            .filter(Person.activated == False)
+            .count()
+        )
+        return deactivated_member_number != 0
+
     def __str__(self):
         return self.what
 

ihatemoney/web.py

@@ -800,13 +800,8 @@ def delete_bill(bill_id):
     if not bill:
         return redirect(url_for(".list_bills"))
 
-    # Prevent deleting if the bill involves deactivated user.
+    # Check if the bill contains deactivated member. If yes, stop deleting.
-    active_member_id = [m.id for m in g.project.active_members]
+    if bill.involves_deactivated_members(g.project):
-    owers_id = [int(m.id) for m in bill.owers]
-    deactivated_members = set([bill.payer_id] + owers_id).difference(
-        set(active_member_id)
-    )
-    if len(deactivated_members):
         flash(
             _("Deactivated users involved. This bill cannot be deleted."),
             category="warning",
@@ -827,21 +822,16 @@ def edit_bill(bill_id):
     if not bill:
         raise NotFound()
 
-    form = get_billform_for(g.project, set_default=False)
+    # Check if the bill contains deactivated member. If yes, stop editing.
-
+    if bill.involves_deactivated_members(g.project):
-    # Prevent editing if the bill involves deactivated user.
-    active_member_id = [m.id for m in g.project.active_members]
-    owers_id = [int(m.id) for m in bill.owers]
-    deactivated_members = set([bill.payer_id] + owers_id).difference(
-        set(active_member_id)
-    )
-    if len(deactivated_members):
         flash(
             _("Deactivated users involved. This bill cannot be edited."),
             category="warning",
         )
         return redirect(url_for(".list_bills"))
 
+    form = get_billform_for(g.project, set_default=False)
+
     if request.method == "POST" and form.validate():
         form.save(bill, g.project)
         db.session.commit()