Use fetch instead of goog.net.XhrIo/XMLHttpRequest

[avm99963]

I'm trying to use the gRPC-Web JS library inside a service worker, where XMLHttpRequest isn't exposed, so gRPC requests don't succeed (instead I get the error ReferenceError: XMLHttpRequest is not defined).

The reason why I want to use gRPC-Web inside a service worker is that I'm developing a Chrome extension, and need to call a gRPC method every 30 minutes, which can only happen inside a service worker.

It would thus be great if the library used fetch instead of goog.net.XhrIo/XMLHttpRequest.

[avm99963]

Just found out that using something like https://github.com/apple502j/xhr-shim lets me work around this problem easily!

Update: xhr-shim doesn't work well (requests are sent but responses are not being received), but it seems like https://github.com/markis/sw-xhr does work.

[sampajano]

Glad you found a solution! 😃

More native Service Worker support would definitely be a plus for gRPC-web too :)

[sampajano]

FYI -- an update about the reason we cannot yet switch to fetch is provided in this related thread :)

[sampajano]

FYI, a solution regarding enabling Fetch was discussed below:
#587 (comment)

[avm99963]

Thanks @sampajano! Should we consider closing this issue in favor of the other one?

[sampajano]

@avm99963 Thanks for suggesting!

The other issue is specifically addressing the service worker use case — while probably tightly related, is maybe a different context. So I think it's ok to keep them as separate for now.

But whatever solution we come up with should address both.. :)

Hope that makes sense :)