Shiny app enigma

[saturne]

Hello,

Launch the app below. Type "yyy" in the text input and then click on the first button (in the table). Then the observer prints "yyy ~~~~ yyy". Now type "zzz" and click on the second button. Then "yyy ~~~~ zzz" is printed. Why "yyy"?

library(shiny)
library(DT)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel = sidebarPanel(
      textInput("txt", "Type text"),
    ),
    mainPanel = mainPanel(
      DTOutput("dtable")
    )
  )
)

server <- function(input, output, session) {
  
  output[["dtable"]] <- renderDT(
    data.frame(
      "content" = rep(input[["txt"]], 5L),
      "buttons" = unlist(lapply(1:5, function(i){
        as.character(
          tags$button(
            id = paste0("ab", i), 
            onclick = "Shiny.setInputValue(this.id, 42, {priority: 'event'})",
            paste0("ab", i)
          )
        )
      }))
    ),
    escape = FALSE
  )
  
  abObserver <- function(i, message = " is greeting you"){
    print(paste("observeEvent is being created:", i))
    observeEvent(input[[paste0("ab", i)]], {
      print(input[[paste0("ab",i)]])
      print(paste0(
        "observing ab", i, " with message: ", message, " ~~~~~ ", input[["txt"]]
      ))
    })
  }

  observerlist <- lapply(1:5, abObserver, message = input[["txt"]])

}

shinyApp(ui, server)