r - 列出 Shiny 的下拉列表selectInput

Question

Shiny 的selectInput小部件需要以下格式的命名选择列表:

choices = list(
  "mpg" = 1,
  "cyl" = 2,
  "disp" = 3,
  "hp" = 4
  # ..... etc
)

转到我 Shiny 的应用程序的数据框将不会具有相同的变量名称，因此我想即时生成名称列表。

这是一个尝试:

data(mtcars)

choices = data.frame(
  var = names(mtcars),
  num = 1:length(names(mtcars))
)

> head(choices)
   var num     mylist
1  mpg   1  "mpg" = 1
2  cyl   2  "cyl" = 2
3 disp   3 "disp" = 3
4   hp   4   "hp" = 4
5 drat   5 "drat" = 5
6   wt   6   "wt" = 6

paste(choices$mylist, collapse = ",")

这看起来很近，但是不起作用:

...
box(
        selectInput(
          "select",
          label = h3("Select box"),
          choices = list(
            paste(choices$mylist, collapse = ",")
          )
    )
...

我该如何进行这项工作？

Answer 1

嗨，如果我理解您的问题对，您可以这样做:

data(mtcars)

choices = data.frame(
  var = names(mtcars),
  num = 1:length(names(mtcars))
)
# List of choices for selectInput
mylist <- as.list(choices$num)
# Name it
names(mylist) <- choices$var
# ui
ui <- fluidPage(
  selectInput(
    "select",
    label = h3("Select box"),
    choices = mylist
  )
)
# server
server <- function(input, output) {

}
# app
shinyApp(ui = ui, server = server)