Create constant for ID_NO_PERSON

aleksis/apps/alsijil/static/js/vue/components/alsijil/PersonalNotes.js

+const ID_NO_PERSON = null;
+
 export default {
+    created() {
+        this.ID_NO_PERSON = ID_NO_PERSON;
+    },
     methods: {
         removePersonalNote(item) {
             console.log("removing personal note", item);
@@ -18,6 +23,9 @@ export default {
             this.editedExtraMarks = personalNote.extra_marks || [];
         },
         personalNoteByStudentID(studentID) {
+            if (this.editedPersonID === ID_NO_PERSON) {
+                return {};
+            }
             return this.personalNotes.filter(item => item.student.id === studentID)[0] || {};
         }
     },
@@ -28,7 +36,7 @@ export default {
             dialog: false,
             // Absent versp. exc. type hw note
             editPersonalNoteId: null,
-            editedPersonID: -1,
+            editedPersonID: ID_NO_PERSON,
             editedTardiness: 0,
             editedAbsent: false,
             editedExcused: false,