r 在Shiny中渲染UI的动态数量

Posted 2021-05-23

library(shiny)

ui = basicPage(
  # inputs
  textInput("txt", "Text"),
  numericInput("n", "Number", 1),
  actionButton("submit", "Submit"),
  # outputs
  uiOutput("ui")
)

server = function(input, output) {
  
  observeEvent(input$submit, {
    n <- input$n
    # construct single ui outputs
    lapply(seq(n), function(i) {
      output[[paste0("ptxt", i)]] <- renderText({ 
        paste0(input$txt, i) 
      })
    })
    # concat ui outputs
    output$ui <- renderUI({
      lapply(seq(n), function(i) {
        textOutput(paste0("ptxt", i))
      })
    })
  })
}

shinyApp(ui, server)