dynamic panels 2

gistfile1.r

ui <- fluidPage(
    fileInput('file', 'File'),
    selectInput('col_select', 'Columns', choices=c(''), multiple=TRUE),
    wellPanel(uiOutput('wellpanels'))
)

server <- function(input, output, session) {

    data <- reactive({
        f <- input$file
        if (! is.null(f))
            read.csv(f$datapath)
    })

    observe({
        d <- data()
        if (! is.null(d))
            updateSelectInput(session, 'col_select', choices=names(d))
    })

    output$wellpanels <- renderUI({
        d <- data()
        if (! is.null(d)) {
            lapply(names(d), function(col) {
                range.col <- range(d[[col]])
                conditionalPanel(condition=paste0('output.panels["', col, '"]'),
                    wellPanel(
                        sliderInput(paste(col, 'slider', sep='_'), strong(col),
                            min=range.col[1], max=range.col[2], value=range.col)
                    )
                )
            })
        }
    })

    output$panels <- reactive({
        d <- data()
        as.list(setNames(names(d) %in% input$col_select, names(d)))
    })
    outputOptions(output, 'panels', suspendWhenHidden=FALSE)

}

runApp(list(ui=ui, server=server))