Shiny example: dynamic input fields

server.r

# Some pre-computed stuff in R. In this example, just assign values to a var
data_sets <- c("mtcars", "morley", "rock")

shinyServer(function(input, output) {

  # Drop-down selection box for which data set
  output$choose_dataset <- reactiveUI(function() {
    selectInput("dataset", "Data set", as.list(data_sets))
  })

  # Check boxes
  output$choose_columns <- reactiveUI(function() {
    # Get the data set with the appropriate name
    dat <- get(input$dataset)
    colnames <- names(dat)

    # Create the checkboxes and select them all by default
    checkboxGroupInput("columns", "Choose columns", 
                        choices  = colnames,
                        selected = colnames)
  })


  # Output the data
  output$data_table <- reactiveTable(function() {
        # Get the data set
        dat <- get(input$dataset)

        # Keep the selected columns
        dat <- dat[, input$columns, drop = FALSE]

        # Return first 20 rows
        head(dat, 20)
  })
})

ui.r

# Define UI for miles per gallon application
shinyUI(pageWithSidebar(

  headerPanel(""),

  sidebarPanel(
    uiOutput("choose_dataset"),

    uiOutput("choose_columns")
  ),


  mainPanel(
    tableOutput("data_table")
  )
))

Hi,

I am new to 'R' , I have gone through the above example. I have a requirement similar to this example.

I am confused from where did you take the data for the above example. can please give some idea for the above example.