In sync sliderInput and textInput

Question

Consider the following shiny app:

library(\'shiny\')

# User Interface/UI

ui <- fluidPage(

  titlePanel(
    \'Slider and Text input update\'
          


        

Answer 1

One way to do it would be using observeEvent for each input and adding a condition if(as.numeric(input$textValue) != input$sliderValue). This will help you from the inputs calling each others update functions recursively. Then your app would look something like this:

library('shiny')

  # User Interface/UI

  ui <- fluidPage(

    titlePanel(
      'Slider and Text input update'
    ), # titlePanel

    mainPanel(

      # Slider input
      sliderInput(
        inputId = 'sliderValue',
        label = 'Slider value',
        min = 0,
        max = 1000,
        value = 500
      ), # sliderInput

      # Text input
      textInput(
        inputId = 'textValue',
        value = 500,
        label = NULL
      ) # textInput

    ) # mainPanel

  ) # fluidPage


  # Server logic

  server <- function(input, output, session)
  {
    observeEvent(input$textValue,{
      if(as.numeric(input$textValue) != input$sliderValue)
      {
        updateSliderInput(
          session = session,
          inputId = 'sliderValue',
          value = input$textValue
        ) # updateSliderInput
      }#if


    })

    observeEvent(input$sliderValue,{
      if(as.numeric(input$textValue) != input$sliderValue)
      {
        updateTextInput(
          session = session,
          inputId = 'textValue',
          value = input$sliderValue
        ) # updateTextInput

      }#if

    })


  }

  # Run the application 
  shinyApp(ui = ui, server = server)

Hope it helps!

Answer 2

The above code can be modified a bit to fix the issue of application getting closed when the input in the test box is empty

   library('shiny')
   ui <- fluidPage(titlePanel('Slider and Text input update'),

                    mainPanel(
                      sliderInput(
                        inputId = 'sliderValue',
                        label = 'Slider value',
                        min = 0,
                        max = 1000,
                        value = 500
                      ),


                      textInput(
                        inputId = 'textValue',
                        value = 500,
                        label = NULL
                      )

                    ))


    # Server logic

    server <- function(input, output, session)
    {
      observeEvent(input$textValue, {
        print(input$textValue)
        if ((as.numeric(input$textValue) != input$sliderValue) &
            input$textValue != "" &  input$sliderValue != "")
        {
          updateSliderInput(
            session = session,
            inputId = 'sliderValue',
            value = input$textValue
          )
        } else {
          if (input$textValue == "") {
            updateSliderInput(session = session,
                              inputId = 'sliderValue',
                              value = 0)

          }
        }


      })

      observeEvent(input$sliderValue, {
        if ((as.numeric(input$textValue) != input$sliderValue) &
            input$sliderValue != "" & input$textValue != "")
        {
          updateTextInput(
            session = session,
            inputId = 'textValue',
            value = input$sliderValue
          )

        }

      })


    }

    # Run the application
    shinyApp(ui = ui, server = server)