r - Shiny:如何创建确认对话框

Question

我想问是否可以有一个确认对话框，由两个按钮组成， Shiny 。比如说，如果我单击“删除”按钮，则会弹出对话框。用户选择并返回。该应用程序根据用户的选择进行操作。

Answer 1

ShinyBS 和 Javascript 都不是必需的。诀窍是使用 modalDialog 并将页脚设置为多个标签的 tagList，通常是用于删除的 actionButton 和 modalButton 取消。下面是 MWE

应用程序.R

library(shiny)

ui = fluidPage(
   mainPanel(
       actionButton("createfile", "Create"),
       actionButton("deletefile", "Delete")
   )
)

# Define server logic required to draw a histogram
server = function(session, input, output) {

   observeEvent(input$createfile, {
       showModal(modalDialog(
           tagList(
               textInput("newfilename", label = "Filename", placeholder = "my_file.txt")
           ), 
           title="Create a file",
           footer = tagList(actionButton("confirmCreate", "Create"),
                            modalButton("Cancel")
           )
       ))
   })


   observeEvent(input$deletefile, {
       showModal(modalDialog(
           tagList(
               selectInput("deletefilename", label = "Delete a file", choices = list.files(pattern="*.txt"))
           ), 
           title="Delete a file",
           footer = tagList(actionButton("confirmDelete", "Delete"),
                            modalButton("Cancel")
           )
       ))
   })

   observeEvent(input$confirmCreate, {
       req(input$newfilename)
       file.create(input$newfilename)
       removeModal()
   })

   observeEvent(input$confirmDelete, {
       req(input$deletefilename)
       file.remove(input$deletefilename)
       removeModal()
   })
}

# Run the application 
shinyApp(ui = ui, server = server)

请注意，如果您使用 Shiny 模块，则必须使用 session$ns("inputID") 而不是 ns("inputID")。请参阅Tobias' answer here .