Index: openacs-4/packages/calendar/tcl/apm-callback-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/calendar/tcl/apm-callback-procs.tcl,v
diff -u -N -r1.3 -r1.3.2.1
--- openacs-4/packages/calendar/tcl/apm-callback-procs.tcl	7 Aug 2017 23:48:05 -0000	1.3
+++ openacs-4/packages/calendar/tcl/apm-callback-procs.tcl	30 Jul 2020 14:23:45 -0000	1.3.2.1
@@ -34,9 +34,37 @@
     }
 }
 
+ad_proc -public calendar::apm::before_uninstantiate {
+    -package_id:required
+} {
+    Cleanup calendars from this package instance upon uninstantiation.
+} {
+    # get calendar ids
+    set calendar_list [db_list get_calendar_ids {
+        SELECT calendar_id FROM calendars
+         WHERE package_id = :package_id
+    }]
+    # delete calendars
+    foreach calendar_id $calendar_list {
+        # delete all calendar items
+        db_foreach get_calendar_items {
+            SELECT cal_item_id FROM cal_items
+             WHERE on_which_calendar = :calendar_id
+        } {
+            calendar::item::delete -cal_item_id $cal_item_id
+        }
+        # delete item types
+        db_foreach get_item_types {
+            SELECT item_type_id FROM cal_item_types
+             WHERE calendar_id= :calendar_id
+        } {
+            calendar::item_type_delete -calendar_id $calendar_id -item_type_id $item_type_id
+        }
+        # delete calendar
+        calendar::delete -calendar_id $calendar_id
+    }
+}
 
-
-
 # Local variables:
 #    mode: tcl
 #    tcl-indent-level: 4