Stopping all javascript events (for example 'shiny:busy') from being fired when using `Shiny.onInputChange`


#1

I'm trying to use Shiny.onInputChange() in javascript to send a message to R when the shiny:busy event gets fired. This causes a never-ending cycle of messages. I'm wondering if anyone can think of a clean way to avoid this infinite recursion, without doing something hacky like creating a boolean flag that gets set to true/false to indicate we should stop.

Sample code:

# Using this to see the messages being sent to shiny
options(shiny.trace=TRUE)

library(shiny)

ui <- fluidPage(
  tags$script("
$(function() {
  $(document).on('shiny:busy', function(event) {
    Shiny.setInputValue('test', 'test',  {priority: 'event'});
  });
});"
  )
)

server <- function(input, output, session) {
  observeEvent(input$test, cat('test'))
}

shinyApp(ui, server)

Conceptually I'm not sure this is possible because shiny is busy when sending a message, but perhaps there's a trick I haven't thought of to tell shiny not to consider itself busy or at least ignore that message. Maybe there's some way to tell what triggered the "busy"ness