updated samples

_sample.go

@@ -26,7 +26,7 @@ func parseflags() {
 	flag.Parse()
 }
 
-func handleevent(m pglisten.Message) {
+func handleevent(m pglisten.Message) bool {
 	if m.Table != "" && m.Op != "" {
 		println(fmt.Sprintf("%s on table %s", m.Op, m.Table))
 	}
@@ -37,7 +37,7 @@ func handleevent(m pglisten.Message) {
 			if k == "id" {
 				if str, ok := v.(string); ok {
 					go func() {
-						cmd := exec.Command("touch", "/tmp/" + str)
+						cmd := exec.Command("touch", "/tmp/"+str)
 						cmd.Run()
 					}()
 				}
@@ -47,6 +47,8 @@ func handleevent(m pglisten.Message) {
 	default:
 		fmt.Println(m.Payload)
 	}
+
+	return true
 }
 
 func main() {

_sample.sql

@@ -1,7 +1,9 @@
+create table pg_notifications_queue (message jsonb);
+
 create function notify_event()
 returns trigger as $$
 declare
-	message json;
+	msg json;
 	payload json;
 	id uuid;
 
@@ -12,19 +14,23 @@ begin
 		id = new.id;
 	end if;
 
-	message = json_build_object(
+	msg = jsonb_build_object(
+		'id', gen_random_uuid(),
 		'table', tg_table_name,
 		'op', tg_op,
 		'trigger', tg_argv[0],
-		'payload', json_build_object('id', id)
+		'payload', json_build_object('id', new.id, 'source', tg_argv[1], 'target', tg_argv[2])
 	);
 
-	perform pg_notify('events', message::text);
+	insert into pg_notifications_queue (message) values (msg::jsonb);
+
+	perform pg_notify('events', msg::text);
 
 	return null;
 end $$ language plpgsql;
 
-
--- create trigger <collection>_notify_event
--- 	after insert or update or delete on <collection>
--- 	for each row execute function notify_event();
+-- create trigger <table>_notify_event
+-- 	after update on <table>
+-- 	for each row
+-- 	when (old.<something> is distinct from new.<something>)
+-- 	execute procedure notify_event('kramdown', '<something>', '<html_something>');