Create a password input control — passwordInput
R/input-password.R
  Description
Create an password control for entry of passwords.
Arguments
- inputId
- The - inputslot that will be used to access the value.
- label
- Display label for the control, or - NULLfor no label.
- value
- Initial value. 
- width
- The width of the input, e.g. - '400px', or- '100%'; see- validateCssUnit().
- placeholder
- A character string giving the user a hint as to what can be entered into the control. Internet Explorer 8 and 9 do not support this option. 
Value
A text input control that can be added to a UI definition.
Server value
A character string of the password input. The default value is ""
unless value is provided.
See also
Other input elements: 
actionButton(),
checkboxGroupInput(),
checkboxInput(),
dateInput(),
dateRangeInput(),
fileInput(),
numericInput(),
radioButtons(),
selectInput(),
sliderInput(),
submitButton(),
textAreaInput(),
textInput(),
varSelectInput()
Examples
## Only run examples in interactive R sessions
if (interactive()) {
ui <- fluidPage(
  passwordInput("password", "Password:"),
  actionButton("go", "Go"),
  verbatimTextOutput("value")
)
server <- function(input, output) {
  output$value <- renderText({
    req(input$go)
    isolate(input$password)
  })
}
shinyApp(ui, server)
}