Shiny by RStudio

Change the value of a textarea input on the client

updateTextAreaInput(session, inputId, label = NULL, value = NULL)


session The session object passed to function given to shinyServer.
inputId The id of the input object.
label The label to set for the input object.
value The value to set for the input object.


Change the value of a textarea input on the client


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).


## Only run examples in interactive R sessions if (interactive()) { ui <- fluidPage( sliderInput("controller", "Controller", 0, 20, 10), textAreaInput("inText", "Input textarea"), textAreaInput("inText2", "Input textarea 2") ) server <- function(input, output, session) { observe({ # We'll use the input$controller variable multiple times, so save it as x # for convenience. x <- input$controller # This will change the value of input$inText, based on x updateTextAreaInput(session, "inText", value = paste("New text", x)) # Can also set the label, this time for input$inText2 updateTextAreaInput(session, "inText2", label = paste("New label", x), value = paste("New text", x)) }) } shinyApp(ui, server) }

See also