shiny/man/selectInput.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/input-select.R
\name{selectInput}
\alias{selectInput}
\alias{selectizeInput}
\title{Create a select list input control}
\usage{
selectInput(
  inputId,
  label,
  choices,
  selected = NULL,
  multiple = FALSE,
  selectize = TRUE,
  width = NULL,
  size = NULL
)

selectizeInput(inputId, ..., options = NULL, width = NULL)
}
\arguments{
\item{inputId}{The \code{input} slot that will be used to access the value.}

\item{label}{Display label for the control, or \code{NULL} for no label.}

\item{choices}{List of values to select from. If elements of the list are
named, then that name --- rather than the value --- is displayed to the
user. It's also possible to group related inputs by providing a named list
whose elements are (either named or unnamed) lists, vectors, or factors. In
this case, the outermost names will be used as the group labels (leveraging
the \verb{<optgroup>} HTML tag) for the elements in the respective sublist. See
the example section for a small demo of this feature.}

\item{selected}{The initially selected value (or multiple values if \code{multiple = TRUE}). If not specified then defaults to the first value for
single-select lists and no values for multiple select lists.}

\item{multiple}{Is selection of multiple items allowed?}

\item{selectize}{Whether to use \pkg{selectize.js} or not.}

\item{width}{The width of the input, e.g. \code{'400px'}, or \code{'100\%'};
see \code{\link[=validateCssUnit]{validateCssUnit()}}.}

\item{size}{Number of items to show in the selection box; a larger number
will result in a taller box. Not compatible with \code{selectize=TRUE}.
Normally, when \code{multiple=FALSE}, a select input will be a drop-down list,
but when \code{size} is set, it will be a box instead.}

\item{...}{Arguments passed to \code{selectInput()}.}

\item{options}{A list of options. See the documentation of \pkg{selectize.js}(\url{https://selectize.dev/docs/usage})
for possible options (character option values inside \code{\link[base:AsIs]{base::I()}} will
be treated as literal JavaScript code; see \code{\link[=renderDataTable]{renderDataTable()}}
for details).}
}
\value{
A select list control that can be added to a UI definition.
}
\description{
Create a select list that can be used to choose a single or multiple items
from a list of values.
}
\details{
By default, \code{selectInput()} and \code{selectizeInput()} use the JavaScript library
\pkg{selectize.js} (\url{https://selectize.dev/}) instead of
the basic select input element. To use the standard HTML select input
element, use \code{selectInput()} with \code{selectize=FALSE}.

In selectize mode, if the first element in \code{choices} has a value of \code{""}, its
name will be treated as a placeholder prompt. For example:
\code{selectInput("letter", "Letter", c("Choose one" = "", LETTERS))}

\strong{Performance note:} \code{selectInput()} and \code{selectizeInput()} can slow down
significantly when thousands of choices are used; with legacy browsers like
Internet Explorer, the user interface may hang for many seconds. For large
numbers of choices, Shiny offers a "server-side selectize" option that
massively improves performance and efficiency; see
\href{https://shiny.rstudio.com/articles/selectize.html}{this selectize article}
on the Shiny Dev Center for details.
}
\note{
The selectize input created from \code{selectizeInput()} allows
deletion of the selected option even in a single select input, which will
return an empty string as its value. This is the default behavior of
\pkg{selectize.js}. However, the selectize input created from
\code{selectInput(..., selectize = TRUE)} will ignore the empty string
value when it is a single choice input and the empty string is not in the
\code{choices} argument. This is to keep compatibility with
\code{selectInput(..., selectize = FALSE)}.
}
\section{Server value}{
 A vector of character strings, usually of length
1, with the value of the selected items. When \code{multiple=TRUE} and
nothing is selected, this value will be \code{NULL}.
}

\examples{
## Only run examples in interactive R sessions
if (interactive()) {

# basic example
shinyApp(
  ui = fluidPage(
    selectInput("variable", "Variable:",
                c("Cylinders" = "cyl",
                  "Transmission" = "am",
                  "Gears" = "gear")),
    tableOutput("data")
  ),
  server = function(input, output) {
    output$data <- renderTable({
      mtcars[, c("mpg", input$variable), drop = FALSE]
    }, rownames = TRUE)
  }
)

# demoing group support in the `choices` arg
shinyApp(
  ui = fluidPage(
    selectInput("state", "Choose a state:",
      list(`East Coast` = list("NY", "NJ", "CT"),
           `West Coast` = list("WA", "OR", "CA"),
           `Midwest` = list("MN", "WI", "IA"))
    ),
    textOutput("result")
  ),
  server = function(input, output) {
    output$result <- renderText({
      paste("You chose", input$state)
    })
  }
)
}

}
\seealso{
\code{\link[=updateSelectInput]{updateSelectInput()}} \code{\link[=varSelectInput]{varSelectInput()}}

Other input elements: 
\code{\link{actionButton}()},
\code{\link{checkboxGroupInput}()},
\code{\link{checkboxInput}()},
\code{\link{dateInput}()},
\code{\link{dateRangeInput}()},
\code{\link{fileInput}()},
\code{\link{numericInput}()},
\code{\link{passwordInput}()},
\code{\link{radioButtons}()},
\code{\link{sliderInput}()},
\code{\link{submitButton}()},
\code{\link{textAreaInput}()},
\code{\link{textInput}()},
\code{\link{varSelectInput}()}
}
\concept{input elements}