dateInput("date","Enter date:",value = date),
       checkboxGroupInput("variable", "Variable:",
                         choices = names ,selected = names
        )

dataall <-  reactive({
     filename <- paste0("dataall_'", input$date, "'.RData")
     load(filename)
     feature.test[,names(feature.test) %in% input$variable]
   })

shiny::runApp(list(
  ui = basicPage(
    selectInput("specy", "Specy", choices = levels(iris$Species)),
    tableOutput("content")
  ),
  server = function(input, output, session) {
    output$content <- renderTable({
      iris[iris$Species == input$specy, ]
    })
  }
))

shiny::runApp(list(
  ui = pageWithSidebar(
    headerPanel("Example"),
    sidebarPanel(
      checkboxGroupInput("variable", "Variable:", choices = names(iris))
    ),
    mainPanel(
     tableOutput("content")
    )
  ),
  server = function(input, output, session) {
    output$content <- renderTable({
      if(is.null(input$variable))
        return()

      iris[input$variable]
    })
  }
))

checkboxGroupInput( "date", "Variable:",
                 choices = names ,selected = names
)