就我个人而言，我对javascript不是很适应，所以我尽可能地避免使用javascript，并在R中使用它。您可以使用updateTextInput更新textInput中的值。

library(shiny)
library(shinyjs)

shinyApp(
  ui = fluidPage(
    useShinyjs(),
    textInput("input",  label = "input", value = "default text"),
    actionButton("clear", label = "clear/disable"),
    actionButton("submit", "submit"),
    tags$div(id="result")
  ),
  server = function(input, output, session) {
    
    observeEvent(input$clear, {
      updateTextInput(session, "input", value = "")
      disable("input")
    })
    
    observeEvent(input$submit, {
      insertUI("#result", ui=renderText(input$input))
    })
  }
)

使用updateTextInput()时坚持使用Javascript并遵循Ronak的想法

library(shinyjs)
library(shiny)

# this is supposed to change the input value to null
jsCode <- 'shinyjs.clear_input = function(params){
    var defaultParams = {
    input_id : null
  }
  ;
  params = shinyjs.getParams(params, defaultParams);
  var el = $("#" + params.input_id);
    el.val(null);}'

shinyApp(
  
  ui = fluidPage(
    useShinyjs(),  
    extendShinyjs(text = jsCode, functions = c("clear_input")),
    textInput("input",  label = "input", value = "default text"),
    actionButton("clear", label = "clear/disable"),
    actionButton("submit", "submit"),
    tags$div(id="result")
  ),
  server = function(input, output) {
    
    observeEvent(input$clear, {
      updateTextInput(inputId="input", value=js$clear_input("input"))
      disable("input")
    })
    
    observeEvent(input$submit, {
      insertUI("#result", ui=renderText(input$input))
    })
  }
)