stateFuncs: Enable/disable an input element
In shinyjs: Easily Improve the User Experience of Your Shiny Apps in Seconds

Description Usage Arguments Note See Also Examples

Enable or disable an input element. A disabled element is not usable and not clickable, while an enabled element (default) can receive user input. Any shiny input tag can be used with these functions.

enable enables an input, disable disabled an input,toggleState enables an input if it is disabled and disables an input if it is already enabled.

If condition is given to toggleState, that condition will be used to determine if to enable or disable the input. The element will be enabled if the condition evaluates to TRUE and disabled otherwise. If you find yourself writing code such as if (test()) enable(id) else disable(id) then you can use toggleState instead: toggleState(id, test()).

enable(id = NULL, selector = NULL, asis = FALSE)

disable(id = NULL, selector = NULL, asis = FALSE)

toggleState(id = NULL, condition = NULL, selector = NULL, asis = FALSE)

`id`	The id of the input element/Shiny tag
`selector`	Query selector of the elements to target. Ignored if the `id` argument is given. For example, to disable all text inputs, use `selector = "input[type='text']"`
`asis`	If `TRUE`, use the ID as-is even when inside a module (instead of adding the namespace prefix to the ID).
`condition`	An optional argument to `toggleState`. The element will be enabled when the `condition` is `TRUE`, and disabled otherwise.

shinyjs must be initialized with a call to useShinyjs() in the app's ui.

useShinyjs, runExample disabled

if (interactive()) {
  library(shiny)

  shinyApp(
    ui = fluidPage(
      useShinyjs(),  # Set up shinyjs
      actionButton("btn", "Click me"),
      textInput("element", "Watch what happens to me")
    ),
    server = function(input, output) {
      observeEvent(input$btn, {
        # Change the following line for more examples
        toggleState("element")
      })
    }
  )
}
## Not run: 
  # The shinyjs function call in the above app can be replaced by
  # any of the following examples to produce similar Shiny apps
  toggleState(id = "element")
  enable("element")
  disable("element")

  # Similarly, the "element" text input can be changed to many other
  # input tags, such as the following examples
  actionButton("element", "I'm a button")
  fileInput("element", "Choose a file")
  selectInput("element", "I'm a select box", 1:10)

## End(Not run)

## toggleState can be given an optional `condition` argument, which
## determines if to enable or disable the input
if (interactive()) {
  shinyApp(
    ui = fluidPage(
      useShinyjs(),
      textInput("text", "Please type at least 3 characters"),
      actionButton("element", "Submit")
    ),
    server = function(input, output) {
      observe({
        toggleState(id = "element", condition = nchar(input$text) >= 3)
      })
    }
  )
}