How to dynamically add items to a dropdownMenu in shinydashboard

dynamic-dropdownMenu.R

library(shiny)
library(shinydashboard)

ui <- dashboardPage(
  dashboardHeader(title = "Dropdowns 2.0",
    dropdownMenuOutput("menu")
  ),
  dashboardSidebar(
    helpText("Add another item to the dropdown menu by clicking ",
             "on the button below"),
    actionButton("addItem", "Add another item")
  ),
  dashboardBody()
)

server <- function(input, output, session) {
  tasks <-  reactiveValues(
      code = list(id = "code", value = 15, color = "aqua",
                  text = "Refactor code"),
      layout = list(id = "layout", value = 40, color = "green",
                    text = "Design new layout"),
      docs = list(id = "docs", value = 25, color = "red",
                  text = "Write documentation")
    )

  # actually render the dropdownMenu
  output$menu <- renderMenu({
    items <- lapply(tasks, function(el) {
      taskItem(value = el$value, color = el$color, text = el$text)
    })
    dropdownMenu(
      type = "tasks", badgeStatus = "danger",
      .list = items
    )
  })

  observeEvent(input$addItem, {
    showModal(modalDialog(title = "Add new task",
      textInput(paste0("id", input$addItem), "Task ID"),
      numericInput(paste0("val", input$addItem), "Task value", 0),
      selectInput(paste0("col", input$addItem), "Task color",
        choices = c("red", "yellow", "aqua", "blue",
          "light-blue", "green", "navy", "teal",
          "olive", "lime", "orange", "fuchsia",
          "purple", "maroon", "black")
      ),
      textInput(paste0("text", input$addItem), "Task text"),
      actionButton(paste0("go", input$addItem), "Add item"),
      easyClose = TRUE, footer = NULL
    ))

    observeEvent(input[[paste0("go", input$addItem)]], {
      tasks[[paste0("id", input$addItem)]] <- list(
        id = input[[paste0("id", input$addItem)]],
        value = input[[paste0("val", input$addItem)]],
        color = input[[paste0("col", input$addItem)]],
        text = input[[paste0("text", input$addItem)]]
      )
      removeModal()
    })
  })
}

shinyApp(ui, server)

Thanks for this great example! However, there is one tricky thing here when I add additional tabs in dashboardSidebar. For example, when I have two tabs and I move to second tab, and then decide to add new task in dynamic dropdownMenu, It will automatically move to first tab. Do you know how to block this behaviour? You can find modified version of your code here.