Joe Cheng

Actually... if you're already writing JavaScript, you could use `session$onFlushed()` to schedule a `shinyjs` call that updates an input on the server. And have an `observeEvent(once=TRUE)` waiting for that input....

> Could this be officially supported? Like I proposed, maybe add a `wait` argument to `renderUI` and in the end of the rendering event, add this `execute_at_next_input` to wait for...

Note to self: Need less aggressive caching of UI

Work around this today by wrapping ui in a function: ``` r ui

@daattali I think you're right that the semantics of removal make sense. You can already take a dependency on a key that isn't represented (yet) in the reactive values object....

Oh man, just stumbling onto this in PR now, it's exactly what we need for Shiny--we're working on a feature to automatically color ggplot2 plots to match with the web...

@rich-iannone I think this is one worth getting your head around, feel free to ping @wch or myself for the full context.

Hi @daattali, I didn't realize how slow `gt::gt(gt::pizzaplace)` was, so thanks even for that feedback alone! @rich-iannone and I talked about this in person. I'd like to investigate two other...

@rich-iannone recently merged a PR that makes this on the order of 10X faster, IIRC. We might still want to do a progress bar, but we're going to move that...

@hadley and I have had conversations about introducing a monadic bind operator for R. The main usages I had in mind were for reactives (from Shiny) and [promises](https://rstudio.github.io/promises/). Promises already...