Question: connect state

[Lucas Löffel]

Hey,

thank you for the great library - just want to ask how i can get informations about the connection progress - how i can retrieve errors when there is e.g. a non 200 status code? Is there something like a connection state?

Thank you!

[Tom Bevan]

Hey! Glad you like the library!

So any of the Subscribe methods should return an error when the connection is initially set up, which should catch any non-200 HTTP status codes. Once the subscription is setup, it's not possible to get the exact error.

You can get connection status through the OnDisconnect callbacks like so:

c, err := sse.NewClient("http://my-sse-endpoint.net")

c.OnDisconnect(func(c *sse.Client) {
    // log the disconnect
})

If you are interested in making use of those errors, I'm happy to extend the OnDisconnect callback to expose those errors?

[Lucas Löffel]

Thanks for your answer!

sse.NewClient don't return a error btw

I am using SubscribeRaw which is not returning an error for 401 - maybe i miss something?

var client = sse.NewClient("https://localhost:3003/api/auth/company/1/group/1/message/event")

if err := client.SubscribeRaw(func(event *sse.Event) {
    // foo
}); err != nil {
    logger.Fatal(err)
}

Edit:

Tested with a lot of 401 errors

[GIN] 2021/02/24 - 14:38:37 | 401 |      73.436µs |      172.20.0.1 | GET      "/api/auth/company/1/group/1/message/event"
[GIN] 2021/02/24 - 14:38:37 | 401 |      71.115µs |      172.20.0.1 | GET      "/api/auth/company/1/group/1/message/event"
[GIN] 2021/02/24 - 14:38:40 | 401 |      55.977µs |      172.20.0.1 | GET      "/api/auth/company/1/group/1/message/event"
[GIN] 2021/02/24 - 14:38:40 | 401 |     104.201µs |      172.20.0.1 | GET      "/api/auth/company/1/group/1/message/event"
[GIN] 2021/02/24 - 14:38:42 | 401 |      41.281µs |      172.20.0.1 | GET      "/api/auth/company/1/group/1/message/event"

[Lucas Löffel]

Got it by using the ReconnectNotify handler

Returning the status code here could be pretty helpful: https://github.com/r3labs/sse/blob/master/client.go#L77

[Tom Bevan]

Cool, thank you for testing that out. Subscribe* should eventually return the error, however the exponential backoff will loop forever by default. You can avoid this by doing something like:

c := NewClient(url)

c.ReconnectStrategy = backoff.WithMaxTries(
    backoff.NewExponentialBackOff(), 
    3,
)

The above PR should include the http status in the error

[Lucas Löffel]

Thanks @purehyperbole for the info!

Just built up this tool for testing our scalable redis sse events and it works great 🎉

https://github.com/makeless/makeless-go-event-client