This is necessary for proxy situations that don't override the
Shiny.createSocket function (so, not including Shiny Server,
but more like Nginx, HAProxy, and a future version of RStudio
Server).
Without the path being preserved, it's impossible for these
proxies to know that the URL should be forwarded to the host
and port that belongs to Shiny.
Some time recently, Google Chrome started actually caring what the
client sends for this and what the server replies with. httpuv
doesn't currently have any logic for subprotocol selection, so
it always replies with no Sec-WebSocket-Protocol header, which
now Google Chrome reacts to by closing the websocket connection.
This problem goes away if we just don't send a subprotocol at all.
plotOutput now takes clickId and hoverId params that tell Shiny
where to send click and hover events for that plot. The server.R
file can listen on input$<clickId> and/or input$<hoverId>. In
both cases, the resulting value will have numeric x and y elements
that indicate the mouse position in user coordinates. In the case
of hover events, it's also possible to have a NULL value which
means the mouse is not currently hovering over the plot.
- If an output is bound in the UI before it exists on the server, the
server will suspend the new output until something else causes
manageHiddenOutputs to be triggered. The refactor in shiny.R sets
the suspended flag to .shouldSuspend.
- As part of the previous refactor, we don't set suspendOnHidden in
defineOutput; instead we leave it empty and .shouldSuspend knows
what the default should be.
- In shiny.js, unbound controls were not being suspended. This was
fixed by having sendOutputHiddenState be stateful; anything in
a visible state that disappears on the next iteration is marked
as hidden. Also unbindAll now calls sendOutputHiddenState.
