Phoenix Channels [warn] Ignoring unmatched topic “topic:subtopic” - How to Avoid Terminal Warning Message?

While running the Phoenix Chat Example App on localhost we are seeing this “noisy” warning:

[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket

code/phoenix-chat-example $ mix phx.server
[info] Running ChatWeb.Endpoint with Cowboy using http://0.0.0.0:4000
09:50:37 - info: compiled 6 files into 2 files, copied 3 in 1.7 sec
[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket
[info] JOIN "chat_room:lobby" to ChatWeb.ChatRoomChannel
  Transport:  Phoenix.Transports.WebSocket (2.0.0)
  Serializer:  Phoenix.Transports.V2.WebSocketSerializer
  Parameters: %{}
[info] Replied chat_room:lobby :ok
[debug] QUERY OK source="messages" db=5.9ms decode=7.3ms
SELECT m0."id", m0."message", m0."name", m0."inserted_at", m0."updated_at" FROM "messages" AS m0 []
[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket
[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket
[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket
[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket
[warn] Ignoring unmatched topic "topic:subtopic" in ChatWeb.UserSocket

The warning just keeps being logged in the Terminal/Console indefinitely while the client is open …

Tried searching Google / GitHub / StackOverflow / Elixir Forum … :mag:

but no obvious solution … :disappointed:

https://elixirforum.com/search?q=unmatched%20topic%20%22topic%3Asubtopic%22

If you know how to remove this warning, please share! Thanks! :vulcan_salute:

Additional Info

  • OS: OSX 10.13.2 (latest)
  • Elixir: v1.5.3 (latest)
  • Phoenix: v1.3.0 (current/stable)
  • Terminal: iTerm v3.1.5
2 Likes

You did not clean up your assets/js/socket.js file…

Remove this (at the end of the file)

// Now that you are connected, you can join channels with a topic:
let channel = socket.channel("topic:subtopic", {})
channel.join()
  .receive("ok", resp => { console.log("Joined successfully", resp) })
.receive("error", resp => { console.log("Unable to join", resp) })
6 Likes

Thanks for your prompt and helpful reply @kokolegorille! :tada:
Commenting out those lines removed the warning. :white_check_mark:
Thanks! :thumbsup:

Please mirror your answer to: https://stackoverflow.com/questions/48226553/phoenix-channels-warn-ignoring-unmatched-topic-topicsubtopic-how-to-avoid
to collect StackOverflow points. :wink:

It’s ok, I am not using SO :slight_smile:

3 Likes

Fair enough. :thumbsup:
SO can be an “unwelcomming” forum. :unamused:
This forum is way better anyway! :sparkles:
Thanks again! Hope you have a great day! :blush:

2 Likes