多个 =T 时选择输入不更新

Question

我开发了一个闪亮的小应用程序，但我希望它在我 select 和 multiple =T 一起显示两个数据集的变量时显示它们。有什么想法吗？

ui.r

library(shiny)

  bootstrapPage(
    selectInput('dataset', 'Choose data set', c('mtcars', 'iris'),multiple = T),
    selectInput('columns', 'Choose variable', "")
  )

server.r

function(input, output, session){

  # updates variable names based on selected dataset 
  outVar = reactive({
    names(get(input$dataset))
  })

  # create separate observeEvents to 
  observeEvent(input$dataset, {
    updateSelectInput(session, "columns", choices = outVar())
  })
}

Answer 1

您需要将选定的输入作为列表传递给 lapply 函数并迭代读取 input$dataset 中的数据集以获得 names()

您可以尝试以下方法：

  # updates variable names based on selected dataset 
  outVar = reactive({
    unlist(lapply(as.list(input$dataset), function(x){data <- get(x);names(data)}))
  })

完整的工作示例：

library(shiny)

ui <- bootstrapPage(
  selectInput('dataset', 'Choose data set', c('mtcars', 'iris'),multiple = T),
  selectInput('columns', 'Choose variable', "")
)

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

  # updates variable names based on selected dataset 
  outVar = reactive({
    unlist(lapply(as.list(input$dataset), function(x){data <- get(x);names(data)}))
  })

  # create separate observeEvents to 
  observeEvent(input$dataset, {
    updateSelectInput(session, "columns", choices = outVar())
  })
}


shinyApp(ui, server)

多个 =T 时选择输入不更新

Selectinput not updated when multiple =T

r

shiny

reactive