Is there a way to perform javascript operations immediately after a renderUI?

sbo · October 11, 2021, 10:48am

I am re-rendering a UI with renderUI. However, I need to attach some jquery plugins on the resulting HTML immediately after it has been attached.

is there a way to perform javascript operations immediately after the HTML has been attached to the DOM, without relying on monitoring the DOM itself for changes?

Till_K · October 11, 2021, 2:41pm

The shinyjs package should be helpful here. See this SO thread for an example that seems similar to what you are trying to achieve.

sbo · October 12, 2021, 8:04am

shinyjs to me seems more like a collection of additional handlers. You can only trigger them procedurally, but the point is that there's nothing to apply them on, if the html hasn't been attached to the DOM. This happens only after the renderUI returns the chunk, which is then delivered client side, and only then the javascript can be executed. However, the renderUI call is now over. How can you trigger a javascript event after that?

nirgrahamuk · October 12, 2021, 8:46am

Maybe this is useful.

github.com/rstudio/shiny

add call back when `renderUI` is done

opened 10:49PM - 25 Mar 21 UTC

lz100

If we use `renderUI` to load some large UI and call the rendered UI associated s…erver functions after the `renderUI`, it will likely cause problems because the UI is just sent to the client and input-binding registration is still ongoing. Simple example: ```r ui <- fluidPage( actionButton("a", "add UI"), uiOutput("ui_out") ) loadserver <- function(input, output, session){ if(input$n1000 > 0) print(1) #### many other things } server <- function(input, output, session) { observeEvent(input$a, { output$ui_out <- renderUI({ lapply(1:1000, function(i) { numericInput(paste0("n", i), paste0("n", i), value = 0) }) }) loadserver(input, output, session) }) } shinyApp(ui, server) ``` I know I can add `req` to prevent the error, but please don't struggle with this. Just imagine `loadserver` comes from a package and you can't do anything in the function. The normal preloading has no problem (load the required UI and server on start), but only causes problems with this dynamic loading. So, let's just say I want to wait until the UI loading and input-binding is complete and do something in the server. Can we have some options: 1. Make `renderUI` sync ("blocking") before executing the next line. Now it is more like async, it only sends out the UI as a message and goes on to the next line. It doesn't know if the input-binding is complete or the expected inputs are registered in the current shiny session. Add an option like `renderUI(wait = TRUE)` 2. I tried to watch for "shiny:value" event on js, but it only tells me the client has received the new UI, but still, it doesn't tell me the loading is complete or shiny session has all the new inputs registered. If we could have all inputs to be registered in "shiny:value", I can watch for them. ``` js //shiny:value { toBeBound : [id1, id2, ...], ... }; var binds; var bound = 0; $(document).on('shiny:value', function(e) { binds = e.toBeBound; }); $(document).on('shiny:bound', function(e) { if (binds.includes(e.target.id)) bound ++ }); setInterval(function() { if (bound == binds.length) { // load server } }, 1000); ```

ismirsehregal · October 12, 2021, 8:55am

Also related:

Javascript event in renderUI after the DOM has actually rendered shiny

Hello, I am trying to run some custom Javascript code in a Shiny application using renderUI, after the DOM is actually updated. The issue is I haven't found a way to identify this event. Here is an example where I want to replace one column in a simple HTML table with sparklines: library(shiny) library(magrittr) library(sparkline) library(htmltools) # build an HTML table from a data.frame # x: data.frame # spk: column index of data to display as sparklines to_html_table <- function(x, spk = NULL) { col_names <- names(x) row.names(x) <- NULL head <- tags$thead( do.call(tags$tr, lapply(col_names, tags$th)) ) # UGLY body <- do.call( tags$tbody, apply( …

system · December 5, 2021, 12:56pm

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