如何删除UI？

如何解决如何删除UI？

我无法使用“删除”按钮删除UI。我尝试添加此

removeUI(
      selector = paste0("div:has(> #row","_",input$addLine," )"),multiple = TRUE,immediate = TRUE,session
    )

，但不起作用。当我单击删除按钮时，什么也没有发生。我想知道我是否没有在selector函数中正确指定removeUI。

有没有办法使这项工作有效，还是应该尝试其他方法？

以下是可重现的示例：

library(shiny)

newlist <- as.list(c("LV1","LV2","x1","x2","x3","x4","x5","x6"))
symbol <- as.list(c("=~","~"))

row_ui <- function(id) {
  ns <- NS(id)
  fluidRow(
    column(2,uiOutput(ns("ui_placeholder"))),column(2,uiOutput(ns("ui_placeholder3"))),uiOutput(ns("ui_placeholder2")))
  )
} 

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

  return_value <- reactive({paste(input$variable1,input$symbol1,paste(input$variable2,collapse = "+"))})
  ns <- session$ns
  output$ui_placeholder <- renderUI({
    selectizeInput(ns("variable1"),"LV:",choices = c(' ',newlist),options=list(create=TRUE),selected = NULL)
  })
  
  output$ui_placeholder2 <- renderUI({
    selectizeInput(ns("variable2"),"Ind:",selected = NULL,multiple = TRUE)
  })
  
  output$ui_placeholder3 <- renderUI({
    selectizeInput(ns("symbol1"),"Type",symbol),selected = NULL)
  })
  
  list(return_value = return_value) 
}

ui <- fluidPage(  
  div(id="placeholder"),actionButton("addLine","+ LV"),actionButton("removeLine","Remove UI")
)

server <- function(input,session) {
  
  handler <- reactiveVal(list())
  
  observeEvent(input$addLine,{
    new_id <- paste("row",sep = "_")
    insertUI(
      selector = "#placeholder",where = "beforeBegin",ui = row_ui(new_id)
    )
    
    handler_list <- isolate(handler())
    new_handler <- callModule(row_server,new_id)
    handler_list <- c(handler_list,new_handler)
    names(handler_list)[length(handler_list)] <- new_id
    handler(handler_list)
    
    removeUI(
      selector = paste0("div:has(> #row",session
    )
})
}

shinyApp(ui,server)

解决方法

也许您正在寻找这个。

library(shiny)

newlist <- as.list(c("LV1","LV2","x1","x2","x3","x4","x5","x6"))
symbol <- as.list(c("=~","~"))

row_ui <- function(id) {
  ns <- NS(id)
  fluidRow(
    column(2,uiOutput(ns("ui_placeholder"))),column(2,uiOutput(ns("ui_placeholder3"))),uiOutput(ns("ui_placeholder2")))
  )
} 

row_server <- function(input,output,session) {
  
  return_value <- reactive({paste(input$variable1,input$symbol1,paste(input$variable2,collapse = "+"))})
  ns <- session$ns
  output$ui_placeholder <- renderUI({
    selectizeInput(ns("variable1"),"LV:",choices = c(' ',newlist),options=list(create=TRUE),selected = NULL)
  })
  
  output$ui_placeholder2 <- renderUI({
    selectizeInput(ns("variable2"),"Ind:",selected = NULL,multiple = TRUE)
  })
  
  output$ui_placeholder3 <- renderUI({
    selectizeInput(ns("symbol1"),"Type",symbol),selected = NULL)
  })
  
  list(return_value = return_value) 
}


ui <- fluidPage(  
  div(id="placeholder"),actionButton("addLine","+ LV"),actionButton("removeLine","Remove UI")
)

server <- function(input,session) {
  
  handler <- reactiveVal(list())
  ### keep track of elements/lines inserted and not yet removed
  inserted <- c()
  observeEvent(input$addLine,{
    new_id <- paste("row",input$addLine,sep = "_")
    insertUI(
      selector = "#placeholder",where = "beforeBegin",ui = tags$div(
        div(row_ui(new_id)),id = new_id
      )
    )
    # inserted <<- c(new_id,inserted)  ##  removes first one first
    inserted <<- c(inserted,new_id)    ##  removes last  one first
    
    handler_list <- isolate(handler())
    new_handler <- callModule(row_server,new_id)
    handler_list <- c(handler_list,new_handler)
    names(handler_list)[length(handler_list)] <- new_id
    handler(handler_list)

  })
  
  observeEvent(input$removeLine,{
    removeUI(
      ## pass in appropriate div id
      selector = paste0('#',inserted[length(inserted)])
    )
    inserted <<- inserted[-length(inserted)]
  })
  
}

shinyApp(ui,server)