Updating shiny input (visually) using JavaScript

Shiny
,
1

In the code below I have a simple app with one slider. By runningShiny.setInputValue('debug', 1) in the browser console, we see that our input value is updated in the R console. However, the slider is not updated visually, is there a function to communicate the new input value back to JS so that the slider value updates?

Screen Shot 2021-05-18 at 12.23.24 PM
Screen Shot 2021-05-18 at 12.23.24 PM2026×1082 174 KB

library(shiny)

ui <- function(request) {
    tagList(
        sliderInput("debug", "debug", value = 2, min = -2, max = 2, step = 0.01)
    )
}

server <- function(input, output, session) {
    
    # run in browser: Shiny.setInputValue('debug', 1)
    # we see this value changes in the R console
    # but the slider itself doesn't visually change/update
    observe({
        print(input$debug)
    })

}

shinyApp(ui, server)
2

Perhaps you can look at how updateSliderInput works

3

Ooh looking at that source code was valuable I now see on the R side I can definitely use session$sendInputMessage("debug", list(value=1)) but I am still curious how you'd go about moving the slider on the JS side/what this function does on the JS side ... I'll keep digging :slight_smile: thank you!

4

Take a look at the example from this documentation: Shiny - Using sliders

You can have a table or something to reflect what value the slider is on. Then when you change the slider, the value in the table will update.