Always use sendBeacon instead of Image where available

[cramforce]

Why would one ever want to use Image instead of sendBeacon?

I think we should always use sendBeacon if we can.

@avimehta @rudygalfi Any opinions?

[avimehta]

yes. Agreed. GA has an open bug where for sendBeacon requests, our servers respond before we get the full request and that has made us not go full sendBeacon. but overall, we would want to go full sendBeacon where possible.

[cramforce]

I don't fully understand: What does "our servers respond before we get the full request" mean?

[rudygalfi]

Is the proposal to change the transport config options?

[cramforce]

Basically to kill the image transport and only use it if sendBeacon is not available.

My main question is: Is there any reason not to do this? Does the image transport do anything that sendBeacon does not?

[avimehta]

Is there any reason not to do this? Does the image transport do anything that sendBeacon does not?

1. sendBeacon is not supported on all browsers.
2. Not many analytics vendors support post yet.

[rudygalfi]

Is @avimehta's latest response sufficient or does this need more discussion?

[igrigorik]

If sendBeacon supported GET, would this allow us to make it the default for all browsers that support it?

[dvoytenko]

@igrigorik I'd think so. I can't think of any reason then not to use it as a default.

[cramforce]

Not going there until w3c/beacon#22 is resolved

[lannka]

A proposal to implement this is here: #7096