A re-orderable list of objects as a shiny input

Displays the selected objects as a vertical list; entries can be dragged to re-order and removed with the X button on the right. The value is a character vector of the entry keys, in the order shown on screen. Implemented using vanilla shiny selectizeInput, hence no additional 'JavaScript' library is needed.

Usage

objectListInput(
  inputId,
  label = NULL,
  choices = NULL,
  selected = NULL,
  width = NULL,
  placeholder = "(No object selected)",
  sortable = TRUE,
  removable = TRUE,
  allow_readd = TRUE
)

updateObjectListInput(
  session = shiny::getDefaultReactiveDomain(),
  inputId,
  label = NULL,
  choices = NULL,
  selected = choices
)

Arguments

inputId, label, width

passed to selectizeInput

choices

a named list or character vector of the entries; the names are the text displayed in each row and the values are the entry keys returned by the input; the order of choices is the order of the rows

selected

keys of the entries to show; default is all of choices

placeholder

text to display when the list is empty

sortable

whether the entries can be dragged to re-order; requires 'jQuery' 'UI' shipped with shiny, and is silently disabled when unavailable

removable

whether each entry has a button to remove itself

allow_readd

whether the entries can be selected again from a drop-down menu; when FALSE the list only shows what the server puts in it, and removing an entry is final until it is added again from the server; when TRUE a removed entry stays available in the menu and re-selecting it appends it to the end of the list; default is TRUE

session

shiny session

Value

objectListInput returns a shiny input; the input value is a character vector of the entry keys in display order. updateObjectListInput is called for its side effect.

Examples

ui <- shiny::basicPage(
  objectListInput(
    inputId = "objects", label = "Selected objects",
    choices = character(),
    selected = character()
  ),
  shiny::actionButton("btn", "Add")
)

if (interactive()) {
  shiny::shinyApp(
    ui = shiny::fluidPage(ui, shiny::verbatimTextOutput("selected")),
    server = function(input, output, session) {
      output$selected <- shiny::renderPrint({ input$objects })

      shiny::bindEvent(
        shiny::observe({
          shidashi::updateObjectListInput(
            inputId = "objects",
            choices = c(
              "Electrode 1 [LA1]" = "elec_1",
              "Streamlines [n=12]" = "streamlines_1",
              "Overlay aparc [discrete]" = "volume_1"
            )
          )
        }),
        input$btn
      )
    }
  )
}