Is a "Internet not connected" momentary flash error expected with pub-sub?

Phoenix Forum Questions / Help
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1

I have a small pub sub app. When updates are made, a red “internet connection” error flashes briefly. Is this expected behavior? If not , any suggestions to “fix” it?

Example: https://i.imgur.com/VLqSVBb.mp4

Thank you.

2

I would check your server logs, are you sure that your page isn’t crashing and then that’s triggering a refresh? The error you see is not expected.

3

This should be solved according to this issue "We can't find the internet" flashes on Page transitions and reloads on Firefox 106.0.5 on Phoenix 1.7-rx.0 · Issue #5102 · phoenixframework/phoenix · GitHub

Make sure you are on the latest version of Phoenix and LiveView. However, I can still see it in Firefox.
I solved it temporary with adding this as a conditional class to the flash component in core components:

@id == "disconnected" && "transition delay-300"

Basically means that it waits 300ms before dislaying it and then it is usually connected and doesnt show up at all.

4

I don’t think that’s the root cause here though. In @wktdev’s video, the other subscribed tab was reloading when the form submitted. He didn’t provide any code, but I’m guessing he is using pubsub and the other page is subscribed to a message that the form submit triggers. If the other page is reloading when it receives a pubsub message that’s probably because it’s crashing.

5

You might be correct.

6

I don’t see any red highlighted errors in the console. The code I used to create Alerts is identical to the code I used to create “testbeds”. When I create “testbeds” I do not get the internet time out message. I’ll post some code in a minute

7

I wrote this for “pub-sub” testbeds.

  def handle_info({TestBeds, [:testbed | _], _}, socket) do
    {:noreply, assign(socket, testbeds: TestBeds.list_testbeds())}
  end

I replicated it for alerts:

  def handle_info({Alerts, [:alert | _], _}, socket) do
    {:noreply, assign(socket, alerts: Alerts.list_alerts())}
  end

Nope!
I accidentally set the code like this:

  def handle_info({Alerts, [:alert | _], _}, socket) do
    {:noreply, assign(socket, alerts: Alerts.list_testbeds())}    # error should be Alert.list_alerts
  end

In the post above I wrote that the code is identical between the testbed and alerts. It forced me to fine-tooth that statement. They weren’t identical. The console had a non-red highlighted error but it was tangled in the rest of the output and I missed it.