--- a/schema/manage_users.sql	Mon Aug 06 12:37:06 2018 +0200
+++ b/schema/manage_users.sql	Mon Aug 06 13:25:18 2018 +0200
@@ -56,35 +56,34 @@
             OR pg_has_role('sys_admin', 'MEMBER');
 
 
-CREATE OR REPLACE FUNCTION sys_admin.create_user(
-       userrole varchar,
-       username internal.user_profiles.username%TYPE,
-       pw varchar,
-       country internal.user_profiles.country%TYPE,
-       map_extent internal.user_profiles.map_extent%TYPE,
-       email_address internal.user_profiles.email_address%TYPE
-    )
-    RETURNS void
+CREATE OR REPLACE FUNCTION internal.create_user() RETURNS trigger
 AS $$
 BEGIN
-    IF map_extent IS NULL
+    IF NEW.map_extent IS NULL
     THEN
-        map_extent = ST_Extent(area) FROM users.responsibility_areas ra
-            WHERE ra.country = create_user.country;
+        NEW.map_extent = ST_Extent(area) FROM users.responsibility_areas ra
+            WHERE ra.country = NEW.country;
     END IF;
     INSERT INTO internal.user_profiles (
         username, country, map_extent, email_address)
-        VALUES (username, country, map_extent, email_address);
+        VALUES (NEW.username, NEW.country, NEW.map_extent, NEW.email_address);
     EXECUTE format(
         'CREATE ROLE %I IN ROLE %I LOGIN PASSWORD %L',
-        username,
-        userrole,
-        internal.check_password(pw));
+        NEW.username,
+        NEW.rolname,
+        internal.check_password(NEW.pw));
+
+    -- Do not leak new password
+    NEW.pw = '';
+    RETURN NEW;
 END;
 $$
     LANGUAGE plpgsql
     SECURITY DEFINER;
 
+CREATE TRIGGER create_user INSTEAD OF INSERT ON users.list_users FOR EACH ROW
+    EXECUTE PROCEDURE internal.create_user();
+
 
 CREATE OR REPLACE FUNCTION internal.update_user() RETURNS trigger
 AS $$