A simple Shiny module with input and output values

module.R

library(shiny)

testModuleInput <- function (id) {
  ns <- NS(id)
  uiOutput(ns("inputUI"))
}

testModule <- function (input, output, session, label) {
  ns <- session$ns
  value <- reactiveValues(value="")
  output$inputUI <- renderUI({
    textInput(ns("text"), label(), value$value)
  })
  observe({
    value$value <- input$text
  })
  return( reactive(value$value) )
} 

appUI <- fluidPage(
  textInput("moduleLabel", "Module label", "default label"),
  testModuleInput("testModule1"),
  textOutput("testOutput")
)

appServer <- function (input, output) {
  module1 <- callModule(testModule, "testModule1", reactive(input$moduleLabel))
  output$testOutput <- renderText(module1())
}

shinyApp(appUI, appServer)

wishedVersion.R

library(shiny)

testModuleUI <- function (id) {
  ns <- NS(id)
  uiOutput(ns("inputUI"))
}

testModule <- function (input, output, session, label) {
  ns <- session$ns
  value <- reactiveValues(value="")
  output$inputUI <- renderUI({
    textInput(ns("text"), label(), value$value)
  })
  observe({
    value$value <- input$text
  })
  return( reactive(value$value) )
} 

appUI <- fluidPage(
  textInput("moduleLabel", "Module label", "default label"),
  moduleOutput("testModule1"),
  textOutput("testOutput")
)

appServer <- function (input, output) {
  output$testModule1 <- callOrRenderModule(testModule, reactive(input$moduleLabel))
  output$testOutput <- renderText(reactive(input$testModule1))
}

shinyApp(appUI, appServer)