我真的不喜欢使用lapply
创建闪亮的输入元素,因为当您添加元素时,现有(选定)输入的输入 UI 会被覆盖,因此所有内容都会设置回默认值,并且之前为这些输入选择的值会丢失。
您可以配对insertUI
with removeUI
和一个变量来跟踪先前选择的列。然后您可以动态添加/删除 UI 元素并保持其他输入不变。
library(shiny)
library(shinyWidgets)
library(DT)
name<-c("John","Jack","Bill")
value1<-c(2,4,6)
add<-c("SDF","GHK","FGH")
value2<-c(3,4,5)
dt<-data.frame(name,value1,add,value2)
# ui object
ui <- fluidPage(
titlePanel(p("Spatial app", style = "color:#3474A7")),
sidebarLayout(
sidebarPanel(
pickerInput(
inputId = "p1",
label = "Select Column headers",
choices = colnames( dt),
multiple = TRUE,
options = list(`actions-box` = TRUE)
),
tags$div(id = "add_ui_here")
),
mainPanel(
)
)
)
# server()
server <- function(input, output) {
# store currently selected columns
selected_columns <- c()
observeEvent(input$p1, {
# determine pickerInputs to remove
input_remove <- !selected_columns %in% input$p1
input_remove <- selected_columns[input_remove]
# remove inputs
if (!is.null(input_remove) && length(input_remove) > 0) {
for (input_element in input_remove) {
removeUI(selector = paste0("#", input_element, "_remove_id"))
}
}
# determine pickerInputs to add
input_add <- !input$p1 %in% selected_columns
input_add <- input$p1[input_add]
# add inputs
if (length(input_add) > 0) {
for (input_element in input_add) {
insertUI(
selector = "#add_ui_here",
where = "afterEnd",
ui = tags$div(id = paste0(input_element, "_remove_id"),
pickerInput(
inputId = input_element
,
label = input_element
,
choices = dt[, input_element]
,
multiple = TRUE,
options = list(`actions-box` = TRUE)
))
)
}
}
# update the currently stored column variable
selected_columns <<- input$p1
},
ignoreNULL = FALSE)
}
# shinyApp()
shinyApp(ui = ui, server = server)
我已经包裹好插入的pickerInputs
in a div
,因此更容易删除它们。另外,你需要设置ignoreNULL = FALSE
对于观察者来说,如果所有元素都被取消选择,它也会被触发。