Update Slider Input Widget — updateSliderInput

v1.8.1|Source: R/update-input.R

Description

Change the value of a slider input on the client.

updateSliderInput(
  session = getDefaultReactiveDomain(),
  inputId,
  label = NULL,
  value = NULL,
  min = NULL,
  max = NULL,
  step = NULL,
  timeFormat = NULL,
  timezone = NULL
)

Arguments

session

The session object passed to function given to shinyServer. Default is getDefaultReactiveDomain().

inputId

The id of the input object.

label

The label to set for the input object.

value

The initial value of the slider, either a number, a date (class Date), or a date-time (class POSIXt). A length one vector will create a regular slider; a length two vector will create a double-ended range slider. Must lie between min and max.

min, max

The minimum and maximum values (inclusive) that can be selected.

step

Specifies the interval between each selectable value on the slider. Either NULL, the default, which uses a heuristic to determine the step size or a single number. If the values are dates, step is in days; if the values are date-times, step is in seconds.

timeFormat

Only used if the values are Date or POSIXt objects. A time format string, to be passed to the Javascript strftime library. See https://github.com/samsonjs/strftime for more details. The allowed format specifications are very similar, but not identical, to those for R's base::strftime() function. For Dates, the default is "%F" (like "2015-07-01"), and for POSIXt, the default is "%F %T" (like "2015-07-01 15:32:10").

timezone

Only used if the values are POSIXt objects. A string specifying the time zone offset for the displayed times, in the format "+HHMM" or "-HHMM". If NULL (the default), times will be displayed in the browser's time zone. The value "+0000" will result in UTC time.

Details

The input updater functions send a message to the client, telling it to change the settings of an input object. The messages are collected and sent after all the observers (including outputs) have finished running.

The syntax of these functions is similar to the functions that created the inputs in the first place. For example, numericInput() and updateNumericInput() take a similar set of arguments.

Any arguments with NULL values will be ignored; they will not result in any changes to the input object on the client.

For radioButtons(), checkboxGroupInput() and selectInput(), the set of choices can be cleared by using choices=character(0). Similarly, for these inputs, the selected item can be cleared by using selected=character(0).

See also

sliderInput()

Examples

## Only run this example in interactive R sessions
if (interactive()) {
  shinyApp(
    ui = fluidPage(
      sidebarLayout(
        sidebarPanel(
          p("The first slider controls the second"),
          sliderInput("control", "Controller:", min=0, max=20, value=10,
                       step=1),
          sliderInput("receive", "Receiver:", min=0, max=20, value=10,
                       step=1)
        ),
        mainPanel()
      )
    ),
    server = function(input, output, session) {
      observe({
        val <- input$control
        # Control the value, min, max, and step.
        # Step size is 2 when input value is even; 1 when value is odd.
        updateSliderInput(session, "receive", value = val,
          min = floor(val/2), max = val+4, step = (val+1)%%2 + 1)
      })
    }
  )
}