From 6035642336b149c070c7ab2b1861668267529ca3 Mon Sep 17 00:00:00 2001
From: Wondertan <hlibwondertan@gmail.com>
Date: Sun, 9 Jan 2022 18:23:33 +0200
Subject: [PATCH] feat: new WithMsgIdFunction topic option to enable topics to
 have own msg id generation rules

---
 pubsub.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pubsub.go b/pubsub.go
index 7caf5ada..e817be44 100644
--- a/pubsub.go
+++ b/pubsub.go
@@ -1160,6 +1160,14 @@ type TopicOptions struct{}
 
 type TopicOpt func(t *Topic) error
 
+// WithMsgIdFunction sets custom MsgIdFunction for a Topic, enabling topics to have own msg id generation rules.
+func (p *PubSub) WithMsgIdFunction(msgId MsgIdFunction) TopicOpt {
+	return func(t *Topic) error {
+		t.p.idGen.Set(t.topic, msgId)
+		return nil
+	}
+}
+
 // Join joins the topic and returns a Topic handle. Only one Topic handle should exist per topic, and Join will error if
 // the Topic handle already exists.
 func (p *PubSub) Join(topic string, opts ...TopicOpt) (*Topic, error) {