Question

我试图在同一个insertUI块中插入一个对selectInput有反应的UI。从概念上讲，insertUI充当一种向用户呈现selectInput的形式，然后基于他/她的选择，呈现一个伴随的selectizeInput。这个想法是，这两个小部件属于相同的输出div，如果用户愿意，可以使用相同的removeUI按钮将其删除。

我从here出发，并且尝试使this answer适应一个相对类似的问题，但是当我单击“添加新表单”时，所有尝试都破坏了该应用程序，返回以下警告：

Warning: Error in if: argument is of length zero
  88: tag
  87: tags$div
  86: div
  85: column
  76: observeEventHandler [~/.active-rstudio-document#33]
   5: runApp
   3: print.shiny.appobj
   1: source

我怀疑我的问题是我试图提取未完全创建的对象的输入值。我希望这不会成为问题，期望selectizeInput是根据selectInput的默认值呈现的，并且如果并且当用户更改selectInput选择时，会重新呈现selectizeInput。不再确定是否可以使用insertUI（还有renderUI的任务）来实现。关于反应性，我还有很多要学习的东西，并且可能有一种更简单的方法来解决这个问题。

这是我上次尝试的简化版本：

library(shiny)
library(shinyjs)
library(shinyWidgets)

ui <- navbarPage(
                  tabPanel(
                          useShinyjs(),
                          hr(),
                          h3("Click the button to add a new form:"),
                             fluidRow(
                               actionBttn(
                                 inputId = "new_form", 
                                 label = "Add new form",
                                 color = "primary",
                                 style = "simple",
                                 size = "sm"
                                 )
                               ),
                             fluidRow(div(id = 'placeholder_new_form'))
                          )
)

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

  observeEvent(input$new_form, {

    # make ids for the plot, the remove button, and the element to remove
    id_add <- paste0("id_", input$new_form)
    remove_id <- paste0("remove_", input$new_form)
    ele_id <- paste0("ele_", input$new_form)
    choice_id <- paste0("choice_", input$new_form)

    insertUI(
      selector = "#placeholder_new_form",
      where = "afterEnd", 
      ui = tags$div(
        id = ele_id,
        fluidRow(
          column (
            width = 6, 
            align = "center",
            selectInput(
              inputId = choice_id, 
              label = "Select a choice", 
              choices = c("Choice 1", "Choice 2", "Choice 3"),
              width = "100%")
            ),
          column(
            width = 6, 
            align = "center",
            if(input$choice_id == "Choice 1"){
              selectizeInput(inputId = "choice_1_options", 
                             label = "Select option from Choice 1:",
                             choices = c("", "Option 1", "Option 2", "Option 3"),
                             options = list(maxItems = 1, placeholder = "Start typing option here...", create = TRUE),
                             width = "100%")

              } else if (input$choice_id == "Choice 2"){
                selectizeInput(inputId = "choice_2_options", 
                               label = "Select option from Choice 2:",
                               choices = c("", "Option 1", "Option 2", "Option 3"),
                               options = list(maxItems = 1, placeholder = "Start typing option here...", create = TRUE),
                               width = "100%")

                } else {
                selectizeInput(inputId = "choice_3_options", 
                               label = "Select option from Choice 3:",
                               choices = c("", "Option 1", "Option 2", "Option 3"),
                               options = list(maxItems = 1, placeholder = "Start typing option here...", create = TRUE),
                               width = "100%")
                  }
            )
          ),
        actionButton(remove_id, "Remove form")
        ),

    observeEvent(input[[remove_id]], {
      removeUI(
        selector = paste0("#", ele_id)
        )
      })
    )

    })
  }

shinyApp(ui = ui, server = server)

我想为用户提供的关键功能是每个新表单都包含selectInput和selectizeInput，他/他可以通过单个removeUI按钮轻松删除整个表单，并添加与s一样多的表单。 /他想要。

在此先感谢您的更正，建议和见解。

如何在insertUI块内使用selectInput的输出来修改insertUI生成的html？

0 个答案: