R Shiny Dynamically add textinput and print ui output based on Userinput

I am trying to create a shiny application which will enable users to add text boxes, or add images and create a document from it. I am able to add one Textbox and display its contents but when I add another textbox, the contents are not displayed. I have used a link as a starting point.

Here is my sample code that I am trying to add more user input text boxes by clicking add button.

library(shiny)
library(shinyjqui)

ui <- shinyUI(fluidPage(

  sidebarPanel(
    actionButton("add_btn", "Add Textbox"),
    actionButton("rm_btn", "Remove Textbox"),
    textOutput("counter")
  ),
  mainPanel(
    jqui_sortable(
      div(id = 'textboxes',
            uiOutput("textbox_ui"),
            textInput("caption", "Caption", "Insert Text"),
            verbatimTextOutput("value")
      )
    )
  )
))

server <- shinyServer(function(input, output, session) {

  # Track the number of input boxes to render
  counter <- reactiveValues(n = 0)

  #Track the number of input boxes previously
  prevcount <- reactiveValues(n = 0)

  observeEvent(input$add_btn, {
    counter$n <- counter$n + 1
    prevcount$n <- counter$n - 1})

  observeEvent(input$rm_btn, {
    if (counter$n > 0) {
      counter$n <- counter$n - 1 
      prevcount$n <- counter$n + 1
    }

  })

  output$value <- renderText({ input$caption })


  output$counter <- renderPrint(print(counter$n))

  textboxes <- reactive({

    n <- counter$n

    if (n > 0) {
      # If the no. of textboxes previously where more than zero, then 
      #save the text inputs in those text boxes 
      if(prevcount$n > 0){

        vals = c()
        if(prevcount$n > n){
          lesscnt <- n
          isInc <- FALSE
        }else{
          lesscnt <- prevcount$n
          isInc <- TRUE
        }
        for(i in 1:lesscnt){
          inpid = paste0("textin",i)
          vals[i] = input[[inpid]] 
        }
        if(isInc){
          vals <- c(vals, "Insert Text")
        }

        lapply(seq_len(n), function(i) {
          textInput(inputId = paste0("textin", i),
                    label = paste0("Subsection ", i), value = vals[i])
        })

      }else{
        lapply(seq_len(n), function(i) {
          textInput(inputId = paste0("textin", i),
                    label = paste0("Subsection ", i), value = "Insert text")
        }) 
      }

    }

  })

  output$textbox_ui <- renderUI({ textboxes() })

})

shinyApp(ui, server)

Any help will be appreciated in this regard. If anyone can point me in how to dynamically capture output$value everytime a new box is added it would push me in the right direction.