Fix room/teacher removing mechanism

aleksis/apps/chronos/frontend/components/substitutions/SubstitutionCard.vue

@@ -241,18 +241,12 @@ export default {
       return this.roomsWithStatus.find((r) => r.id === room.id)?.status;
     },
     removeTeacher(teacher) {
-      const index = this.teachers.indexOf(teacher.id);
-      if (index >= 0) {
-        this.teachers.splice(index, 1);
-        this.save();
-      }
+      this.teachers = this.substitutionTeacherIDs.filter((t) => t !== teacher.id);
+      this.save(true);
     },
     removeRoom(room) {
-      const index = this.rooms.indexOf(room.id);
-      if (index >= 0) {
-        this.rooms.splice(index, 1);
-        this.save();
-      }
+      this.rooms = this.substitutionRoomIDs.filter((r) => r !== room.id);
+      this.save(true);
     },
     teachersInput(teachers) {
       this.teachers = teachers;
@@ -266,8 +260,9 @@ export default {
       this.cancelled = cancelled;
       this.save();
     },
-    save() {
+    save(allowEmpty = false) {
       if (
+        allowEmpty ||
         this.teachers.length ||
         this.rooms.length ||
         this.comment !== null ||
@@ -276,8 +271,8 @@ export default {
         this.createOrPatch([
           {
             id: this.substitution.id,
-            ...(this.teachers.length && { teachers: this.teachers }),
-            ...(this.rooms.length && { rooms: this.rooms }),
+            ...((allowEmpty || this.teachers.length) && { teachers: this.teachers }),
+            ...((allowEmpty || this.rooms.length) && { rooms: this.rooms }),
             ...(this.comment !== null && { comment: this.comment }),
             ...(this.cancelled !== null && { cancelled: this.cancelled }),
           },