When an automatic upgrade completes, or when the user clicks on the upgrade
button in one webapp, but also has it open in another browser window/tab,
we have a problem: The current web server is going to stop running in
minutes, but there is no way to send a redirect to the web browser to the
new url.
To solve this, used long polling, so the webapp is always listening for
urls it should redirect to. This allows globally redirecting every open
webapp. Works great! Tested with 2 web browsers with 2 tabs each.
May be useful for other purposes later too, dunno.
The overhead is 2 http requests per page load in the webapp. Due to yesod's
speed, this does not seem to noticibly delay it. Only 1 of the requests
could possibly block the page load, the other is async.
The only thing lost is ./ghci
Speed: make fast used to take 20 seconds here, when rebuilding from
touching Command/Unused.hs. With cabal, it's 29 seconds.
For no apparent reason, this version removes all useful instances of
ToJavaScript, leavind behind only an instance for Aeson.Value. Argh. Pissed
off at this arbitrary breaking change, and seriously considering dropping
this library.
This means that anyone serving up the webapp to users as a service
(ie, without providing any git-annex binary at all to the user) still needs
to provide a link to the source code for it, including any modifications
they may make.
This may make git-annex be covered by the AGPL as a whole when it is built
with the webapp. If in doubt, you should ask a lawyer.
When git-annex is built with the webapp disabled, no AGPLed code is used.
Even building in the assistant does not pull in AGPLed code.
