R/bootstrap.R

Defines functions bootstrapPage bootstrapLib basicPage fillPage collapseSizes pageWithSidebar navbarPage navbarMenu headerPanel wellPanel sidebarPanel mainPanel conditionalPanel helpText tabPanel tabsetPanel navlistPanel buildTabset textOutput verbatimTextOutput imageOutput plotOutput tableOutput dataTableOutput htmlOutput downloadButton downloadLink icon iconClass

Documented in basicPage bootstrapLib bootstrapPage conditionalPanel dataTableOutput downloadButton downloadLink fillPage headerPanel helpText htmlOutput icon imageOutput mainPanel navbarMenu navbarPage navlistPanel pageWithSidebar plotOutput sidebarPanel tableOutput tabPanel tabsetPanel textOutput verbatimTextOutput wellPanel

#' @include utils.R
NULL

#' Create a Bootstrap page
#'
#' Create a Shiny UI page that loads the CSS and JavaScript for
#' \href{http://getbootstrap.com/}{Bootstrap}, and has no content in the page
#' body (other than what you provide).
#'
#' This function is primarily intended for users who are proficient in HTML/CSS,
#' and know how to lay out pages in Bootstrap. Most applications should use
#' \code{\link{fluidPage}} along with layout functions like
#' \code{\link{fluidRow}} and \code{\link{sidebarLayout}}.
#'
#' @param ... The contents of the document body.
#' @param title The browser window title (defaults to the host URL of the page)
#' @param responsive This option is deprecated; it is no longer optional with
#'   Bootstrap 3.
#' @param theme Alternative Bootstrap stylesheet (normally a css file within the
#'   www directory, e.g. \code{www/bootstrap.css})
#'
#' @return A UI defintion that can be passed to the \link{shinyUI} function.
#'
#' @note The \code{basicPage} function is deprecated, you should use the
#'   \code{\link{fluidPage}} function instead.
#'
#' @seealso \code{\link{fluidPage}}, \code{\link{fixedPage}}
#'
#' @export
bootstrapPage <- function(..., title = NULL, responsive = NULL, theme = NULL) {

  if (!is.null(responsive)) {
    shinyDeprecated("The 'responsive' argument is no longer used with Bootstrap 3.")
  }

  attachDependencies(
    tagList(
      if (!is.null(title)) tags$head(tags$title(title)),
      if (!is.null(theme)) {
        tags$head(tags$link(rel="stylesheet", type="text/css", href = theme))
      },

      # remainder of tags passed to the function
      list(...)
    ),
    bootstrapLib()
  )
}

#' Bootstrap libraries
#'
#' This function returns a set of web dependencies necessary for using Bootstrap
#' components in a web page.
#'
#' It isn't necessary to call this function if you use
#' \code{\link{bootstrapPage}} or others which use \code{bootstrapPage}, such
#' \code{\link{basicPage}}, \code{\link{fluidPage}}, \code{\link{fillPage}},
#' \code{\link{pageWithSidebar}}, and \code{\link{navbarPage}}, because they
#' already include the Bootstrap web dependencies.
#'
#' @inheritParams bootstrapPage
#' @export
bootstrapLib <- function(theme = NULL) {
  htmlDependency("bootstrap", "3.3.6",
    c(
      href = "shared/bootstrap",
      file = system.file("www/shared/bootstrap", package = "shiny")
    ),
    script = c(
      "js/bootstrap.min.js",
      # These shims are necessary for IE 8 compatibility
      "shim/html5shiv.min.js",
      "shim/respond.min.js"
    ),
    stylesheet = if (is.null(theme)) "css/bootstrap.min.css",
    meta = list(viewport = "width=device-width, initial-scale=1")
  )
}

#' @rdname bootstrapPage
#' @export
basicPage <- function(...) {
  bootstrapPage(div(class="container-fluid", list(...)))
}


#' Create a page that fills the window
#'
#' \code{fillPage} creates a page whose height and width always fill the
#' available area of the browser window.
#'
#' The \code{\link{fluidPage}} and \code{\link{fixedPage}} functions are used
#' for creating web pages that are laid out from the top down, leaving
#' whitespace at the bottom if the page content's height is smaller than the
#' browser window, and scrolling if the content is larger than the window.
#'
#' \code{fillPage} is designed to latch the document body's size to the size of
#' the window. This makes it possible to fill it with content that also scales
#' to the size of the window.
#'
#' For example, \code{fluidPage(plotOutput("plot", height = "100\%"))} will not
#' work as expected; the plot element's effective height will be \code{0},
#' because the plot's containing elements (\code{<div>} and \code{<body>}) have
#' \emph{automatic} height; that is, they determine their own height based on
#' the height of their contained elements. However,
#' \code{fillPage(plotOutput("plot", height = "100\%"))} will work because
#' \code{fillPage} fixes the \code{<body>} height at 100\% of the window height.
#'
#' Note that \code{fillPage(plotOutput("plot"))} will not cause the plot to fill
#' the page. Like most Shiny output widgets, \code{plotOutput}'s default height
#' is a fixed number of pixels. You must explicitly set \code{height = "100\%"}
#' if you want a plot (or htmlwidget, say) to fill its container.
#'
#' One must be careful what layouts/panels/elements come between the
#' \code{fillPage} and the plots/widgets. Any container that has an automatic
#' height will cause children with \code{height = "100\%"} to misbehave. Stick
#' to functions that are designed for fill layouts, such as the ones in this
#' package.
#'
#' @param ... Elements to include within the page.
#' @param padding Padding to use for the body. This can be a numeric vector
#'   (which will be interpreted as pixels) or a character vector with valid CSS
#'   lengths. The length can be between one and four. If one, then that value
#'   will be used for all four sides. If two, then the first value will be used
#'   for the top and bottom, while the second value will be used for left and
#'   right. If three, then the first will be used for top, the second will be
#'   left and right, and the third will be bottom. If four, then the values will
#'   be interpreted as top, right, bottom, and left respectively.
#' @param title The title to use for the browser window/tab (it will not be
#'   shown in the document).
#' @param bootstrap If \code{TRUE}, load the Bootstrap CSS library.
#' @param theme URL to alternative Bootstrap stylesheet.
#'
#' @examples
#' fillPage(
#'   tags$style(type = "text/css",
#'     ".half-fill { width: 50%; height: 100%; }",
#'     "#one { float: left; background-color: #ddddff; }",
#'     "#two { float: right; background-color: #ccffcc; }"
#'   ),
#'   div(id = "one", class = "half-fill",
#'     "Left half"
#'   ),
#'   div(id = "two", class = "half-fill",
#'     "Right half"
#'   ),
#'   padding = 10
#' )
#'
#' fillPage(
#'   fillRow(
#'     div(style = "background-color: red; width: 100%; height: 100%;"),
#'     div(style = "background-color: blue; width: 100%; height: 100%;")
#'   )
#' )
#'
#' @export
fillPage <- function(..., padding = 0, title = NULL, bootstrap = TRUE,
  theme = NULL) {

  fillCSS <- tags$head(tags$style(type = "text/css",
    "html, body { width: 100%; height: 100%; overflow: hidden; }",
    sprintf("body { padding: %s; margin: 0; }", collapseSizes(padding))
  ))

  if (isTRUE(bootstrap)) {
    bootstrapPage(title = title, theme = theme, fillCSS, ...)
  } else {
    tagList(
      fillCSS,
      if (!is.null(title)) tags$head(tags$title(title)),
      ...
    )
  }
}

collapseSizes <- function(padding) {
  paste(
    sapply(padding, shiny::validateCssUnit, USE.NAMES = FALSE),
    collapse = " ")
}

#' Create a page with a sidebar
#'
#' Create a Shiny UI that contains a header with the application title, a
#' sidebar for input controls, and a main area for output.
#'
#' @param headerPanel The \link{headerPanel} with the application title
#' @param sidebarPanel The \link{sidebarPanel} containing input controls
#' @param mainPanel The \link{mainPanel} containing outputs

#' @return A UI defintion that can be passed to the \link{shinyUI} function
#'
#' @note This function is deprecated. You should use \code{\link{fluidPage}}
#' along with \code{\link{sidebarLayout}} to implement a page with a sidebar.
#'
#' @examples
#' # Define UI
#' pageWithSidebar(
#'
#'   # Application title
#'   headerPanel("Hello Shiny!"),
#'
#'   # Sidebar with a slider input
#'   sidebarPanel(
#'     sliderInput("obs",
#'                 "Number of observations:",
#'                 min = 0,
#'                 max = 1000,
#'                 value = 500)
#'   ),
#'
#'   # Show a plot of the generated distribution
#'   mainPanel(
#'     plotOutput("distPlot")
#'   )
#' )
#'
#' @export
pageWithSidebar <- function(headerPanel,
                            sidebarPanel,
                            mainPanel) {

  bootstrapPage(
    # basic application container divs
    div(
      class="container-fluid",
      div(class="row",
          headerPanel
      ),
      div(class="row",
          sidebarPanel,
          mainPanel
      )
    )
  )
}

#' Create a page with a top level navigation bar
#'
#' Create a page that contains a top level navigation bar that can be used to
#' toggle a set of \code{\link{tabPanel}} elements.
#'
#' @param title The title to display in the navbar
#' @param ... \code{\link{tabPanel}} elements to include in the page. The
#'   \code{navbarMenu} function also accepts strings, which will be used as menu
#'   section headers. If the string is a set of dashes like \code{"----"} a
#'   horizontal separator will be displayed in the menu.
#' @param id If provided, you can use \code{input$}\emph{\code{id}} in your
#'   server logic to determine which of the current tabs is active. The value
#'   will correspond to the \code{value} argument that is passed to
#'   \code{\link{tabPanel}}.
#' @param selected The \code{value} (or, if none was supplied, the \code{title})
#'   of the tab that should be selected by default. If \code{NULL}, the first
#'   tab will be selected.
#' @param position Determines whether the navbar should be displayed at the top
#'   of the page with normal scrolling behavior (\code{"static-top"}), pinned at
#'   the top (\code{"fixed-top"}), or pinned at the bottom
#'   (\code{"fixed-bottom"}). Note that using \code{"fixed-top"} or
#'   \code{"fixed-bottom"} will cause the navbar to overlay your body content,
#'   unless you add padding, e.g.: \code{tags$style(type="text/css", "body
#'   {padding-top: 70px;}")}
#' @param header Tag or list of tags to display as a common header above all
#'   tabPanels.
#' @param footer Tag or list of tags to display as a common footer below all
#'   tabPanels
#' @param inverse \code{TRUE} to use a dark background and light text for the
#'   navigation bar
#' @param collapsible \code{TRUE} to automatically collapse the navigation
#'   elements into a menu when the width of the browser is less than 940 pixels
#'   (useful for viewing on smaller touchscreen device)
#' @param collapsable Deprecated; use \code{collapsible} instead.
#' @param fluid \code{TRUE} to use a fluid layout. \code{FALSE} to use a fixed
#'   layout.
#' @param responsive This option is deprecated; it is no longer optional with
#'   Bootstrap 3.
#' @param theme Alternative Bootstrap stylesheet (normally a css file within the
#'   www directory). For example, to use the theme located at
#'   \code{www/bootstrap.css} you would use \code{theme = "bootstrap.css"}.
#' @param windowTitle The title that should be displayed by the browser window.
#'   Useful if \code{title} is not a string.
#' @param icon Optional icon to appear on a \code{navbarMenu} tab.
#'
#' @return A UI defintion that can be passed to the \link{shinyUI} function.
#'
#' @details The \code{navbarMenu} function can be used to create an embedded
#'   menu within the navbar that in turns includes additional tabPanels (see
#'   example below).
#'
#' @seealso \code{\link{tabPanel}}, \code{\link{tabsetPanel}},
#'   \code{\link{updateNavbarPage}}
#'
#' @examples
#' navbarPage("App Title",
#'   tabPanel("Plot"),
#'   tabPanel("Summary"),
#'   tabPanel("Table")
#' )
#'
#' navbarPage("App Title",
#'   tabPanel("Plot"),
#'   navbarMenu("More",
#'     tabPanel("Summary"),
#'     "----",
#'     "Section header",
#'     tabPanel("Table")
#'   )
#' )
#' @export
navbarPage <- function(title,
                       ...,
                       id = NULL,
                       selected = NULL,
                       position = c("static-top", "fixed-top", "fixed-bottom"),
                       header = NULL,
                       footer = NULL,
                       inverse = FALSE,
                       collapsible = FALSE,
                       collapsable,
                       fluid = TRUE,
                       responsive = NULL,
                       theme = NULL,
                       windowTitle = title) {

  if (!missing(collapsable)) {
    shinyDeprecated("`collapsable` is deprecated; use `collapsible` instead.")
    collapsible <- collapsable
  }

  # alias title so we can avoid conflicts w/ title in withTags
  pageTitle <- title

  # navbar class based on options
  navbarClass <- "navbar navbar-default"
  position <- match.arg(position)
  if (!is.null(position))
    navbarClass <- paste(navbarClass, " navbar-", position, sep = "")
  if (inverse)
    navbarClass <- paste(navbarClass, "navbar-inverse")

  # build the tabset
  tabs <- list(...)
  tabset <- buildTabset(tabs, "nav navbar-nav", NULL, id, selected)

  # built the container div dynamically to support optional collapsibility
  if (collapsible) {
    navId <- paste("navbar-collapse-", p_randomInt(1000, 10000), sep="")
    containerDiv <- div(class="container",
      div(class="navbar-header",
        tags$button(type="button", class="navbar-toggle collapsed",
          `data-toggle`="collapse", `data-target`=paste0("#", navId),
          span(class="sr-only", "Toggle navigation"),
          span(class="icon-bar"),
          span(class="icon-bar"),
          span(class="icon-bar")
        ),
        span(class="navbar-brand", pageTitle)
      ),
      div(class="navbar-collapse collapse", id=navId, tabset$navList)
    )
  } else {
    containerDiv <- div(class="container",
      div(class="navbar-header",
        span(class="navbar-brand", pageTitle)
      ),
      tabset$navList
    )
  }

  # function to return plain or fluid class name
  className <- function(name) {
    if (fluid)
      paste(name, "-fluid", sep="")
    else
      name
  }

  # build the main tab content div
  contentDiv <- div(class=className("container"))
  if (!is.null(header))
    contentDiv <- tagAppendChild(contentDiv, div(class="row", header))
  contentDiv <- tagAppendChild(contentDiv, tabset$content)
  if (!is.null(footer))
    contentDiv <- tagAppendChild(contentDiv, div(class="row", footer))

  # build the page
  bootstrapPage(
    title = windowTitle,
    responsive = responsive,
    theme = theme,
    tags$nav(class=navbarClass, role="navigation", containerDiv),
    contentDiv
  )
}

#' @rdname navbarPage
#' @export
navbarMenu <- function(title, ..., icon = NULL) {
  structure(list(title = title,
                 tabs = list(...),
                 iconClass = iconClass(icon)),
            class = "shiny.navbarmenu")
}

#' Create a header panel
#'
#' Create a header panel containing an application title.
#'
#' @param title An application title to display
#' @param windowTitle The title that should be displayed by the browser window.
#'   Useful if \code{title} is not a string.
#' @return A headerPanel that can be passed to \link{pageWithSidebar}
#'
#' @examples
#' headerPanel("Hello Shiny!")
#' @export
headerPanel <- function(title, windowTitle=title) {
  tagList(
    tags$head(tags$title(windowTitle)),
    div(class="col-sm-12",
      h1(title)
    )
  )
}

#' Create a well panel
#'
#' Creates a panel with a slightly inset border and grey background. Equivalent
#' to Bootstrap's \code{well} CSS class.
#'
#' @param ... UI elements to include inside the panel.
#' @return The newly created panel.
#'
#' @export
wellPanel <- function(...) {
  div(class="well", ...)
}

#' Create a sidebar panel
#'
#' Create a sidebar panel containing input controls that can in turn be passed
#' to \code{\link{sidebarLayout}}.
#'
#' @param ... UI elements to include on the sidebar
#' @param width The width of the sidebar. For fluid layouts this is out of 12
#'   total units; for fixed layouts it is out of whatever the width of the
#'   sidebar's parent column is.
#' @return A sidebar that can be passed to \code{\link{sidebarLayout}}
#'
#' @examples
#' # Sidebar with controls to select a dataset and specify
#' # the number of observations to view
#' sidebarPanel(
#'   selectInput("dataset", "Choose a dataset:",
#'               choices = c("rock", "pressure", "cars")),
#'
#'   numericInput("obs", "Observations:", 10)
#' )
#' @export
sidebarPanel <- function(..., width = 4) {
  div(class=paste0("col-sm-", width),
    tags$form(class="well",
      ...
    )
  )
}

#' Create a main panel
#'
#' Create a main panel containing output elements that can in turn be passed to
#' \code{\link{sidebarLayout}}.
#'
#' @param ... Output elements to include in the main panel
#' @param width The width of the main panel. For fluid layouts this is out of 12
#'   total units; for fixed layouts it is out of whatever the width of the main
#'   panel's parent column is.
#' @return A main panel that can be passed to \code{\link{sidebarLayout}}.
#'
#' @examples
#' # Show the caption and plot of the requested variable against mpg
#' mainPanel(
#'    h3(textOutput("caption")),
#'    plotOutput("mpgPlot")
#' )
#' @export
mainPanel <- function(..., width = 8) {
  div(class=paste0("col-sm-", width),
    ...
  )
}

#' Conditional Panel
#'
#' Creates a panel that is visible or not, depending on the value of a
#' JavaScript expression. The JS expression is evaluated once at startup and
#' whenever Shiny detects a relevant change in input/output.
#'
#' In the JS expression, you can refer to \code{input} and \code{output}
#' JavaScript objects that contain the current values of input and output. For
#' example, if you have an input with an id of \code{foo}, then you can use
#' \code{input.foo} to read its value. (Be sure not to modify the input/output
#' objects, as this may cause unpredictable behavior.)
#'
#' @param condition A JavaScript expression that will be evaluated repeatedly to
#'   determine whether the panel should be displayed.
#' @param ... Elements to include in the panel.
#'
#' @note You are not recommended to use special JavaScript characters such as a
#'   period \code{.} in the input id's, but if you do use them anyway, for
#'   example, \code{inputId = "foo.bar"}, you will have to use
#'   \code{input["foo.bar"]} instead of \code{input.foo.bar} to read the input
#'   value.
#' @examples
#' sidebarPanel(
#'    selectInput(
#'       "plotType", "Plot Type",
#'       c(Scatter = "scatter",
#'         Histogram = "hist")),
#'
#'    # Only show this panel if the plot type is a histogram
#'    conditionalPanel(
#'       condition = "input.plotType == 'hist'",
#'       selectInput(
#'          "breaks", "Breaks",
#'          c("Sturges",
#'            "Scott",
#'            "Freedman-Diaconis",
#'            "[Custom]" = "custom")),
#'
#'       # Only show this panel if Custom is selected
#'       conditionalPanel(
#'          condition = "input.breaks == 'custom'",
#'          sliderInput("breakCount", "Break Count", min=1, max=1000, value=10)
#'       )
#'    )
#' )
#'
#' @export
conditionalPanel <- function(condition, ...) {
  div('data-display-if'=condition, ...)
}

#' Create a help text element
#'
#' Create help text which can be added to an input form to provide additional
#' explanation or context.
#'
#' @param ... One or more help text strings (or other inline HTML elements)
#' @return A help text element that can be added to a UI definition.
#'
#' @examples
#' helpText("Note: while the data view will show only",
#'          "the specified number of observations, the",
#'          "summary will be based on the full dataset.")
#' @export
helpText <- function(...) {
  span(class="help-block", ...)
}


#' Create a tab panel
#'
#' Create a tab panel that can be included within a \code{\link{tabsetPanel}}.
#'
#' @param title Display title for tab
#' @param ... UI elements to include within the tab
#' @param value The value that should be sent when \code{tabsetPanel} reports
#'   that this tab is selected. If omitted and \code{tabsetPanel} has an
#'   \code{id}, then the title will be used..
#' @param icon Optional icon to appear on the tab. This attribute is only
#' valid when using a \code{tabPanel} within a \code{\link{navbarPage}}.
#' @return A tab that can be passed to \code{\link{tabsetPanel}}
#'
#' @seealso \code{\link{tabsetPanel}}
#'
#' @examples
#' # Show a tabset that includes a plot, summary, and
#' # table view of the generated distribution
#' mainPanel(
#'   tabsetPanel(
#'     tabPanel("Plot", plotOutput("plot")),
#'     tabPanel("Summary", verbatimTextOutput("summary")),
#'     tabPanel("Table", tableOutput("table"))
#'   )
#' )
#' @export
tabPanel <- function(title, ..., value = title, icon = NULL) {
  divTag <- div(class="tab-pane",
                title=title,
                `data-value`=value,
                `data-icon-class` = iconClass(icon),
                ...)
}

#' Create a tabset panel
#'
#' Create a tabset that contains \code{\link{tabPanel}} elements. Tabsets are
#' useful for dividing output into multiple independently viewable sections.
#'
#' @param ... \code{\link{tabPanel}} elements to include in the tabset
#' @param id If provided, you can use \code{input$}\emph{\code{id}} in your
#'   server logic to determine which of the current tabs is active. The value
#'   will correspond to the \code{value} argument that is passed to
#'   \code{\link{tabPanel}}.
#' @param selected The \code{value} (or, if none was supplied, the \code{title})
#'   of the tab that should be selected by default. If \code{NULL}, the first
#'   tab will be selected.
#' @param type Use "tabs" for the standard look; Use "pills" for a more plain
#'   look where tabs are selected using a background fill color.
#' @param position This argument is deprecated; it has been discontinued in
#'   Bootstrap 3.
#' @return A tabset that can be passed to \code{\link{mainPanel}}
#'
#' @seealso \code{\link{tabPanel}}, \code{\link{updateTabsetPanel}}
#'
#' @examples
#' # Show a tabset that includes a plot, summary, and
#' # table view of the generated distribution
#' mainPanel(
#'   tabsetPanel(
#'     tabPanel("Plot", plotOutput("plot")),
#'     tabPanel("Summary", verbatimTextOutput("summary")),
#'     tabPanel("Table", tableOutput("table"))
#'   )
#' )
#' @export
tabsetPanel <- function(...,
                        id = NULL,
                        selected = NULL,
                        type = c("tabs", "pills"),
                        position = NULL) {
  if (!is.null(position)) {
    shinyDeprecated(msg = paste("tabsetPanel: argument 'position' is deprecated;",
                                "it has been discontinued in Bootstrap 3."),
                    version = "0.10.2.2")
  }

  # build the tabset
  tabs <- list(...)
  type <- match.arg(type)
  tabset <- buildTabset(tabs, paste0("nav nav-", type), NULL, id, selected)

  # create the content
  first <- tabset$navList
  second <- tabset$content

  # create the tab div
  tags$div(class = "tabbable", first, second)
}

#' Create a navigation list panel
#'
#' Create a navigation list panel that provides a list of links on the left
#' which navigate to a set of tabPanels displayed to the right.
#'
#' @param ... \code{\link{tabPanel}} elements to include in the navlist
#' @param id If provided, you can use \code{input$}\emph{\code{id}} in your
#'   server logic to determine which of the current navlist items is active. The
#'   value will correspond to the \code{value} argument that is passed to
#'   \code{\link{tabPanel}}.
#' @param selected The \code{value} (or, if none was supplied, the \code{title})
#'   of the navigation item that should be selected by default. If \code{NULL},
#'   the first navigation will be selected.
#' @param well \code{TRUE} to place a well (gray rounded rectangle) around the
#'   navigation list.
#' @param fluid \code{TRUE} to use fluid layout; \code{FALSE} to use fixed
#'   layout.
#' @param widths Column withs of the navigation list and tabset content areas
#'   respectively.
#'
#' @details You can include headers within the \code{navlistPanel} by including
#'   plain text elements in the list. Versions of Shiny before 0.11 supported
#'   separators with "------", but as of 0.11, separators were no longer
#'   supported. This is because version 0.11 switched to Bootstrap 3, which
#'   doesn't support separators.
#'
#' @seealso \code{\link{tabPanel}}, \code{\link{updateNavlistPanel}}
#' @examples
#' fluidPage(
#'
#'   titlePanel("Application Title"),
#'
#'   navlistPanel(
#'     "Header",
#'     tabPanel("First"),
#'     tabPanel("Second"),
#'     tabPanel("Third")
#'   )
#' )
#' @export
navlistPanel <- function(...,
                         id = NULL,
                         selected = NULL,
                         well = TRUE,
                         fluid = TRUE,
                         widths = c(4, 8)) {

  # text filter for headers
  textFilter <- function(text) {
      tags$li(class="navbar-brand", text)
  }

  # build the tabset
  tabs <- list(...)
  tabset <- buildTabset(tabs,
                        "nav nav-pills nav-stacked",
                        textFilter,
                        id,
                        selected)

  # create the columns
  columns <- list(
    column(widths[[1]], class=ifelse(well, "well", ""), tabset$navList),
    column(widths[[2]], tabset$content)
  )

  # return the row
  if (fluid)
    fluidRow(columns)
  else
    fixedRow(columns)
}


buildTabset <- function(tabs, ulClass, textFilter = NULL,
                        id = NULL, selected = NULL) {

  # This function proceeds in two phases. First, it scans over all the items
  # to find and mark which tab should start selected. Then it actually builds
  # the tab nav and tab content lists.

  # Mark an item as selected
  markSelected <- function(x) {
    attr(x, "selected") <- TRUE
    x
  }

  # Returns TRUE if an item is selected
  isSelected <- function(x) {
    isTRUE(attr(x, "selected", exact = TRUE))
  }

  # Returns TRUE if a list of tab items contains a selected tab, FALSE
  # otherwise.
  containsSelected <- function(tabs) {
    any(vapply(tabs, isSelected, logical(1)))
  }

  # Take a pass over all tabs, and mark the selected tab.
  foundSelectedItem <- FALSE
  findAndMarkSelected <- function(tabs, selected) {
    lapply(tabs, function(divTag) {
      if (foundSelectedItem) {
        # If we already found the selected tab, no need to keep looking

      } else if (is.character(divTag)) {
        # Strings don't represent selectable items

      } else if (inherits(divTag, "shiny.navbarmenu")) {
        # Navbar menu
        divTag$tabs <- findAndMarkSelected(divTag$tabs, selected)

      } else {
        # Regular tab item
        if (is.null(selected)) {
          # If selected tab isn't specified, mark first available item
          # as selected.
          foundSelectedItem <<- TRUE
          divTag <- markSelected(divTag)

        } else {
          # If selected tab is specified, check for a match
          tabValue <- divTag$attribs$`data-value` %OR% divTag$attribs$title
          if (identical(selected, tabValue)) {
            foundSelectedItem <<- TRUE
            divTag <- markSelected(divTag)
          }
        }
      }

      return(divTag)
    })
  }


  # Append an optional icon to an aTag
  appendIcon <- function(aTag, iconClass) {
    if (!is.null(iconClass)) {
      # for font-awesome we specify fixed-width
      if (grepl("fa-", iconClass, fixed = TRUE))
        iconClass <- paste(iconClass, "fa-fw")
      aTag <- tagAppendChild(aTag, icon(name = NULL, class = iconClass))
    }
    aTag
  }

  # Build the tabset
  build <- function(tabs, ulClass, textFilter = NULL, id = NULL) {
    # add tab input sentinel class if we have an id
    if (!is.null(id))
      ulClass <- paste(ulClass, "shiny-tab-input")

    if (anyNamed(tabs)) {
      nms <- names(tabs)
      nms <- nms[nzchar(nms)]
      stop("Tabs should all be unnamed arguments, but some are named: ",
           paste(nms, collapse = ", "))
    }

    tabNavList <- tags$ul(class = ulClass, id = id)
    tabContent <- tags$div(class = "tab-content")
    tabsetId <- p_randomInt(1000, 10000)
    tabId <- 1

    buildItem <- function(divTag) {
      # check for text; pass it to the textFilter or skip it if there is none
      if (is.character(divTag)) {
        if (!is.null(textFilter)) {
          tabNavList <<- tagAppendChild(tabNavList, textFilter(divTag))
        }

      } else if (inherits(divTag, "shiny.navbarmenu")) {

        # create the a tag
        aTag <- tags$a(href="#",
                       class="dropdown-toggle",
                       `data-toggle`="dropdown")

        # add optional icon
        aTag <- appendIcon(aTag, divTag$iconClass)

        # add the title and caret
        aTag <- tagAppendChild(aTag, divTag$title)
        aTag <- tagAppendChild(aTag, tags$b(class="caret"))

        # build the dropdown list element
        liTag <- tags$li(class = "dropdown", aTag)

        # text filter for separators
        textFilter <- function(text) {
          if (grepl("^\\-+$", text))
            tags$li(class="divider")
          else
            tags$li(class="dropdown-header", text)
        }

        # build the child tabset
        tabset <- build(divTag$tabs, "dropdown-menu", textFilter)
        liTag <- tagAppendChild(liTag, tabset$navList)

        # If this navbar menu contains a selected item, mark it as active
        if (containsSelected(divTag$tabs)) {
          liTag$attribs$class <- paste(liTag$attribs$class, "active")
        }

        tabNavList <<- tagAppendChild(tabNavList, liTag)
        # don't add a standard tab content div, rather add the list of tab
        # content divs that are contained within the tabset
        tabContent <<- tagAppendChildren(tabContent,
                                        list = tabset$content$children)

      } else {
        # Standard navbar item
        # compute id and assign it to the div
        thisId <- paste("tab", tabsetId, tabId, sep="-")
        divTag$attribs$id <- thisId
        tabId <<- tabId + 1

        tabValue <- divTag$attribs$`data-value`

        # create the a tag
        aTag <- tags$a(href=paste("#", thisId, sep=""),
                       `data-toggle` = "tab",
                       `data-value` = tabValue)

        # append optional icon
        aTag <- appendIcon(aTag, divTag$attribs$`data-icon-class`)

        # add the title
        aTag <- tagAppendChild(aTag, divTag$attribs$title)

        # create the li tag
        liTag <- tags$li(aTag)

        # If selected, set appropriate classes on li tag and div tag.
        if (isSelected(divTag)) {
          liTag$attribs$class <- "active"
          divTag$attribs$class <- "tab-pane active"
        }

        divTag$attribs$title <- NULL

        # append the elements to our lists
        tabNavList <<- tagAppendChild(tabNavList, liTag)
        tabContent <<- tagAppendChild(tabContent, divTag)
      }
    }

    lapply(tabs, buildItem)
    list(navList = tabNavList, content = tabContent)
  }


  # Finally, actually invoke the functions to do the processing.
  tabs <- findAndMarkSelected(tabs, selected)
  build(tabs, ulClass, textFilter, id)
}


#' Create a text output element
#'
#' Render a reactive output variable as text within an application page. The
#' text will be included within an HTML \code{div} tag by default.
#' @param outputId output variable to read the value from
#' @param container a function to generate an HTML element to contain the text
#' @param inline use an inline (\code{span()}) or block container (\code{div()})
#'   for the output
#' @return A text output element that can be included in a panel
#' @details Text is HTML-escaped prior to rendering. This element is often used
#'   to display \link{renderText} output variables.
#' @examples
#' h3(textOutput("caption"))
#' @export
textOutput <- function(outputId, container = if (inline) span else div, inline = FALSE) {
  container(id = outputId, class = "shiny-text-output")
}

#' Create a verbatim text output element
#'
#' Render a reactive output variable as verbatim text within an
#' application page. The text will be included within an HTML \code{pre} tag.
#' @param outputId output variable to read the value from
#' @return A verbatim text output element that can be included in a panel
#' @details Text is HTML-escaped prior to rendering. This element is often used
#' with the \link{renderPrint} function to preserve fixed-width formatting
#' of printed objects.
#' @examples
#' mainPanel(
#'   h4("Summary"),
#'   verbatimTextOutput("summary"),
#'
#'   h4("Observations"),
#'   tableOutput("view")
#' )
#' @export
verbatimTextOutput <- function(outputId) {
  textOutput(outputId, container = pre)
}


#' @name plotOutput
#' @rdname plotOutput
#' @export
imageOutput <- function(outputId, width = "100%", height="400px",
                        click = NULL, dblclick = NULL,
                        hover = NULL, hoverDelay = NULL, hoverDelayType = NULL,
                        brush = NULL,
                        clickId = NULL, hoverId = NULL,
                        inline = FALSE) {

  if (!is.null(clickId)) {
    shinyDeprecated(
      msg = paste("The 'clickId' argument is deprecated. ",
                  "Please use 'click' instead. ",
                  "See ?imageOutput or ?plotOutput for more information."),
      version = "0.11.1"
    )
    click <- clickId
  }

  if (!is.null(hoverId)) {
    shinyDeprecated(
      msg = paste("The 'hoverId' argument is deprecated. ",
                  "Please use 'hover' instead. ",
                  "See ?imageOutput or ?plotOutput for more information."),
      version = "0.11.1"
    )
    hover <- hoverId
  }

  if (!is.null(hoverDelay) || !is.null(hoverDelayType)) {
    shinyDeprecated(
      msg = paste("The 'hoverDelay'and 'hoverDelayType' arguments are deprecated. ",
                  "Please use 'hoverOpts' instead. ",
                  "See ?imageOutput or ?plotOutput for more information."),
      version = "0.11.1"
    )
    hover <- hoverOpts(id = hover, delay = hoverDelay, delayType = hoverDelayType)
  }

  style <- if (!inline) {
    paste("width:", validateCssUnit(width), ";", "height:", validateCssUnit(height))
  }


  # Build up arguments for call to div() or span()
  args <- list(
    id = outputId,
    class = "shiny-image-output",
    style = style
  )

  # Given a named list with options, replace names like "delayType" with
  # "data-hover-delay-type" (given a prefix "hover")
  formatOptNames <- function(opts, prefix) {
    newNames <- paste("data", prefix, names(opts), sep = "-")
    # Replace capital letters with "-" and lowercase letter
    newNames <- gsub("([A-Z])", "-\\L\\1", newNames, perl = TRUE)
    names(opts) <- newNames
    opts
  }

  if (!is.null(click)) {
    # If click is a string, turn it into clickOpts object
    if (is.character(click)) {
      click <- clickOpts(id = click)
    }
    args <- c(args, formatOptNames(click, "click"))
  }

  if (!is.null(dblclick)) {
    if (is.character(dblclick)) {
      dblclick <- clickOpts(id = dblclick)
    }
    args <- c(args, formatOptNames(dblclick, "dblclick"))
  }

  if (!is.null(hover)) {
    if (is.character(hover)) {
      hover <- hoverOpts(id = hover)
    }
    args <- c(args, formatOptNames(hover, "hover"))
  }

  if (!is.null(brush)) {
    if (is.character(brush)) {
      brush <- brushOpts(id = brush)
    }
    args <- c(args, formatOptNames(brush, "brush"))
  }

  container <- if (inline) span else div
  do.call(container, args)
}

#' Create an plot or image output element
#'
#' Render a \code{\link{renderPlot}} or \code{\link{renderImage}} within an
#' application page.
#'
#' @section Interactive plots:
#'
#'   Plots and images in Shiny support mouse-based interaction, via clicking,
#'   double-clicking, hovering, and brushing. When these interaction events
#'   occur, the mouse coordinates will be sent to the server as \code{input$}
#'   variables, as specified by \code{click}, \code{dblclick}, \code{hover}, or
#'   \code{brush}.
#'
#'   For \code{plotOutput}, the coordinates will be sent scaled to the data
#'   space, if possible. (At the moment, plots generated by base graphics and
#'   ggplot2 support this scaling, although plots generated by lattice and
#'   others do not.) If scaling is not possible, the raw pixel coordinates will
#'   be sent. For \code{imageOutput}, the coordinates will be sent in raw pixel
#'   coordinates.
#'
#'   With ggplot2 graphics, the code in \code{renderPlot} should return a ggplot
#'   object; if instead the code prints the ggplot2 object with something like
#'   \code{print(p)}, then the coordinates for interactive graphics will not be
#'   properly scaled to the data space.
#'
#' @param outputId output variable to read the plot/image from.
#' @param width,height Image width/height. Must be a valid CSS unit (like
#'   \code{"100\%"}, \code{"400px"}, \code{"auto"}) or a number, which will be
#'   coerced to a string and have \code{"px"} appended. These two arguments are
#'   ignored when \code{inline = TRUE}, in which case the width/height of a plot
#'   must be specified in \code{renderPlot()}. Note that, for height, using
#'   \code{"auto"} or \code{"100\%"} generally will not work as expected,
#'   because of how height is computed with HTML/CSS.
#' @param click This can be \code{NULL} (the default), a string, or an object
#'   created by the \code{\link{clickOpts}} function. If you use a value like
#'   \code{"plot_click"} (or equivalently, \code{clickOpts(id="plot_click")}),
#'   the plot will send coordinates to the server whenever it is clicked, and
#'   the value will be accessible via \code{input$plot_click}. The value will be
#'   a named list  with \code{x} and \code{y} elements indicating the mouse
#'   position.
#' @param dblclick This is just like the \code{click} argument, but for
#'   double-click events.
#' @param hover Similar to the \code{click} argument, this can be \code{NULL}
#'   (the default), a string, or an object created by the
#'   \code{\link{hoverOpts}} function. If you use a value like
#'   \code{"plot_hover"} (or equivalently, \code{hoverOpts(id="plot_hover")}),
#'   the plot will send coordinates to the server pauses on the plot, and the
#'   value will be accessible via \code{input$plot_hover}. The value will be a
#'   named list with \code{x} and \code{y} elements indicating the mouse
#'   position. To control the hover time or hover delay type, you must use
#'   \code{\link{hoverOpts}}.
#' @param clickId Deprecated; use \code{click} instead. Also see the
#'   \code{\link{clickOpts}} function.
#' @param hoverId Deprecated; use \code{hover} instead. Also see the
#'   \code{\link{hoverOpts}} function.
#' @param hoverDelay Deprecated; use \code{hover} instead. Also see the
#'   \code{\link{hoverOpts}} function.
#' @param hoverDelayType Deprecated; use \code{hover} instead. Also see the
#'   \code{\link{hoverOpts}} function.
#' @param brush Similar to the \code{click} argument, this can be \code{NULL}
#'   (the default), a string, or an object created by the
#'   \code{\link{brushOpts}} function. If you use a value like
#'   \code{"plot_brush"} (or equivalently, \code{brushOpts(id="plot_brush")}),
#'   the plot will allow the user to "brush" in the plotting area, and will send
#'   information about the brushed area to the server, and the value will be
#'   accessible via \code{input$plot_brush}. Brushing means that the user will
#'   be able to draw a rectangle in the plotting area and drag it around. The
#'   value will be a named list with \code{xmin}, \code{xmax}, \code{ymin}, and
#'   \code{ymax} elements indicating the brush area. To control the brush
#'   behavior, use \code{\link{brushOpts}}. Multiple
#'   \code{imageOutput}/\code{plotOutput} calls may share the same \code{id}
#'   value; brushing one image or plot will cause any other brushes with the
#'   same \code{id} to disappear.
#' @inheritParams textOutput
#' @note The arguments \code{clickId} and \code{hoverId} only work for R base
#'   graphics (see the \pkg{\link{graphics}} package). They do not work for
#'   \pkg{\link[grid:grid-package]{grid}}-based graphics, such as \pkg{ggplot2},
#'   \pkg{lattice}, and so on.
#'
#' @return A plot or image output element that can be included in a panel.
#' @seealso For the corresponding server-side functions, see
#'   \code{\link{renderPlot}} and  \code{\link{renderImage}}.
#'
#' @examples
#' # Only run these examples in interactive R sessions
#' if (interactive()) {
#'
#' # A basic shiny app with a plotOutput
#' shinyApp(
#'   ui = fluidPage(
#'     sidebarLayout(
#'       sidebarPanel(
#'         actionButton("newplot", "New plot")
#'       ),
#'       mainPanel(
#'         plotOutput("plot")
#'       )
#'     )
#'   ),
#'   server = function(input, output) {
#'     output$plot <- renderPlot({
#'       input$newplot
#'       # Add a little noise to the cars data
#'       cars2 <- cars + rnorm(nrow(cars))
#'       plot(cars2)
#'     })
#'   }
#' )
#'
#'
#' # A demonstration of clicking, hovering, and brushing
#' shinyApp(
#'   ui = basicPage(
#'     fluidRow(
#'       column(width = 4,
#'         plotOutput("plot", height=300,
#'           click = "plot_click",  # Equiv, to click=clickOpts(id="plot_click")
#'           hover = hoverOpts(id = "plot_hover", delayType = "throttle"),
#'           brush = brushOpts(id = "plot_brush")
#'         ),
#'         h4("Clicked points"),
#'         tableOutput("plot_clickedpoints"),
#'         h4("Brushed points"),
#'         tableOutput("plot_brushedpoints")
#'       ),
#'       column(width = 4,
#'         verbatimTextOutput("plot_clickinfo"),
#'         verbatimTextOutput("plot_hoverinfo")
#'       ),
#'       column(width = 4,
#'         wellPanel(actionButton("newplot", "New plot")),
#'         verbatimTextOutput("plot_brushinfo")
#'       )
#'     )
#'   ),
#'   server = function(input, output, session) {
#'     data <- reactive({
#'       input$newplot
#'       # Add a little noise to the cars data so the points move
#'       cars + rnorm(nrow(cars))
#'     })
#'     output$plot <- renderPlot({
#'       d <- data()
#'       plot(d$speed, d$dist)
#'     })
#'     output$plot_clickinfo <- renderPrint({
#'       cat("Click:\n")
#'       str(input$plot_click)
#'     })
#'     output$plot_hoverinfo <- renderPrint({
#'       cat("Hover (throttled):\n")
#'       str(input$plot_hover)
#'     })
#'     output$plot_brushinfo <- renderPrint({
#'       cat("Brush (debounced):\n")
#'       str(input$plot_brush)
#'     })
#'     output$plot_clickedpoints <- renderTable({
#'       # For base graphics, we need to specify columns, though for ggplot2,
#'       # it's usually not necessary.
#'       res <- nearPoints(data(), input$plot_click, "speed", "dist")
#'       if (nrow(res) == 0)
#'         return()
#'       res
#'     })
#'     output$plot_brushedpoints <- renderTable({
#'       res <- brushedPoints(data(), input$plot_brush, "speed", "dist")
#'       if (nrow(res) == 0)
#'         return()
#'       res
#'     })
#'   }
#' )
#'
#'
#' # Demo of clicking, hovering, brushing with imageOutput
#' # Note that coordinates are in pixels
#' shinyApp(
#'   ui = basicPage(
#'     fluidRow(
#'       column(width = 4,
#'         imageOutput("image", height=300,
#'           click = "image_click",
#'           hover = hoverOpts(
#'             id = "image_hover",
#'             delay = 500,
#'             delayType = "throttle"
#'           ),
#'           brush = brushOpts(id = "image_brush")
#'         )
#'       ),
#'       column(width = 4,
#'         verbatimTextOutput("image_clickinfo"),
#'         verbatimTextOutput("image_hoverinfo")
#'       ),
#'       column(width = 4,
#'         wellPanel(actionButton("newimage", "New image")),
#'         verbatimTextOutput("image_brushinfo")
#'       )
#'     )
#'   ),
#'   server = function(input, output, session) {
#'     output$image <- renderImage({
#'       input$newimage
#'
#'       # Get width and height of image output
#'       width  <- session$clientData$output_image_width
#'       height <- session$clientData$output_image_height
#'
#'       # Write to a temporary PNG file
#'       outfile <- tempfile(fileext = ".png")
#'
#'       png(outfile, width=width, height=height)
#'       plot(rnorm(200), rnorm(200))
#'       dev.off()
#'
#'       # Return a list containing information about the image
#'       list(
#'         src = outfile,
#'         contentType = "image/png",
#'         width = width,
#'         height = height,
#'         alt = "This is alternate text"
#'       )
#'     })
#'     output$image_clickinfo <- renderPrint({
#'       cat("Click:\n")
#'       str(input$image_click)
#'     })
#'     output$image_hoverinfo <- renderPrint({
#'       cat("Hover (throttled):\n")
#'       str(input$image_hover)
#'     })
#'     output$image_brushinfo <- renderPrint({
#'       cat("Brush (debounced):\n")
#'       str(input$image_brush)
#'     })
#'   }
#' )
#'
#' }
#' @export
plotOutput <- function(outputId, width = "100%", height="400px",
                       click = NULL, dblclick = NULL,
                       hover = NULL, hoverDelay = NULL, hoverDelayType = NULL,
                       brush = NULL,
                       clickId = NULL, hoverId = NULL,
                       inline = FALSE) {

  # Result is the same as imageOutput, except for HTML class
  res <- imageOutput(outputId, width, height, click, dblclick,
                     hover, hoverDelay, hoverDelayType, brush,
                     clickId, hoverId, inline)

  res$attribs$class <- "shiny-plot-output"
  res
}

#' Create a table output element
#'
#' Render a \code{\link{renderTable}} or \code{\link{renderDataTable}} within an
#' application page. \code{renderTable} uses a standard HTML table, while
#' \code{renderDataTable} uses the DataTables Javascript library to create an
#' interactive table with more features.
#'
#' @param outputId output variable to read the table from
#' @return A table output element that can be included in a panel
#'
#' @seealso \code{\link{renderTable}}, \code{\link{renderDataTable}}.
#' @examples
#' ## Only run this example in interactive R sessions
#' if (interactive()) {
#'   # table example
#'   shinyApp(
#'     ui = fluidPage(
#'       fluidRow(
#'         column(12,
#'           tableOutput('table')
#'         )
#'       )
#'     ),
#'     server = function(input, output) {
#'       output$table <- renderTable(iris)
#'     }
#'   )
#'
#'
#'   # DataTables example
#'   shinyApp(
#'     ui = fluidPage(
#'       fluidRow(
#'         column(12,
#'           dataTableOutput('table')
#'         )
#'       )
#'     ),
#'     server = function(input, output) {
#'       output$table <- renderDataTable(iris)
#'     }
#'   )
#' }
#' @export
tableOutput <- function(outputId) {
  div(id = outputId, class="shiny-html-output")
}

dataTableDependency <- list(
  htmlDependency(
    "datatables", "1.10.5", c(href = "shared/datatables"),
    script = "js/jquery.dataTables.min.js"
  ),
  htmlDependency(
    "datatables-bootstrap", "1.10.5", c(href = "shared/datatables"),
    stylesheet = c("css/dataTables.bootstrap.css", "css/dataTables.extra.css"),
    script = "js/dataTables.bootstrap.js"
  )
)

#' @rdname tableOutput
#' @export
dataTableOutput <- function(outputId) {
  attachDependencies(
    div(id = outputId, class="shiny-datatable-output"),
    dataTableDependency
  )
}

#' Create an HTML output element
#'
#' Render a reactive output variable as HTML within an application page. The
#' text will be included within an HTML \code{div} tag, and is presumed to
#' contain HTML content which should not be escaped.
#'
#' \code{uiOutput} is intended to be used with \code{renderUI} on the server
#' side. It is currently just an alias for \code{htmlOutput}.
#'
#' @param outputId output variable to read the value from
#' @param ... Other arguments to pass to the container tag function. This is
#'   useful for providing additional classes for the tag.
#' @inheritParams textOutput
#' @return An HTML output element that can be included in a panel
#' @examples
#' htmlOutput("summary")
#'
#' # Using a custom container and class
#' tags$ul(
#'   htmlOutput("summary", container = tags$li, class = "custom-li-output")
#' )
#' @export
htmlOutput <- function(outputId, inline = FALSE,
  container = if (inline) span else div, ...)
{
  if (anyUnnamed(list(...))) {
    warning("Unnamed elements in ... will be replaced with dynamic UI.")
  }
  container(id = outputId, class="shiny-html-output", ...)
}

#' @rdname htmlOutput
#' @export
uiOutput <- htmlOutput

#' Create a download button or link
#'
#' Use these functions to create a download button or link; when clicked, it
#' will initiate a browser download. The filename and contents are specified by
#' the corresponding \code{\link{downloadHandler}} defined in the server
#' function.
#'
#' @param outputId The name of the output slot that the \code{downloadHandler}
#'   is assigned to.
#' @param label The label that should appear on the button.
#' @param class Additional CSS classes to apply to the tag, if any.
#'
#' @examples
#' \dontrun{
#' # In server.R:
#' output$downloadData <- downloadHandler(
#'   filename = function() {
#'     paste('data-', Sys.Date(), '.csv', sep='')
#'   },
#'   content = function(con) {
#'     write.csv(data, con)
#'   }
#' )
#'
#' # In ui.R:
#' downloadLink('downloadData', 'Download')
#' }
#'
#' @aliases downloadLink
#' @seealso downloadHandler
#' @export
downloadButton <- function(outputId,
                           label="Download",
                           class=NULL) {
  aTag <- tags$a(id=outputId,
                 class=paste('btn btn-default shiny-download-link', class),
                 href='',
                 target='_blank',
                 icon("download"),
                 label)
}

#' @rdname downloadButton
#' @export
downloadLink <- function(outputId, label="Download", class=NULL) {
  tags$a(id=outputId,
         class=paste(c('shiny-download-link', class), collapse=" "),
         href='',
         target='_blank',
         label)
}


#' Create an icon
#'
#' Create an icon for use within a page. Icons can appear on their own, inside
#' of a button, or as an icon for a \code{\link{tabPanel}} within a
#' \code{\link{navbarPage}}.
#'
#' @param name Name of icon. Icons are drawn from the
#'   \href{http://fontawesome.io/icons/}{Font Awesome} and
#'   \href{http://getbootstrap.com/components/#glyphicons}{Glyphicons"}
#'   libraries. Note that the "fa-" and "glyphicon-" prefixes should not be used
#'   in icon names (i.e. the "fa-calendar" icon should be referred to as
#'   "calendar")
#' @param class Additional classes to customize the style of the icon (see the
#'   \href{http://fontawesome.io/examples/}{usage examples} for details on
#'   supported styles).
#' @param lib Icon library to use ("font-awesome" or "glyphicon")
#'
#' @return An icon element
#'
#' @seealso For lists of available icons, see
#'   \href{http://fontawesome.io/icons/}{http://fontawesome.io/icons/} and
#'   \href{http://getbootstrap.com/components/#glyphicons}{http://getbootstrap.com/components/#glyphicons}.
#'
#'
#' @examples
#' icon("calendar")               # standard icon
#' icon("calendar", "fa-3x")      # 3x normal size
#' icon("cog", lib = "glyphicon") # From glyphicon library
#'
#' # add an icon to a submit button
#' submitButton("Update View", icon = icon("refresh"))
#'
#' navbarPage("App Title",
#'   tabPanel("Plot", icon = icon("bar-chart-o")),
#'   tabPanel("Summary", icon = icon("list-alt")),
#'   tabPanel("Table", icon = icon("table"))
#' )
#'
#' @export
icon <- function(name, class = NULL, lib = "font-awesome") {
  prefixes <- list(
    "font-awesome" = "fa",
    "glyphicon" = "glyphicon"
  )
  prefix <- prefixes[[lib]]

  # determine stylesheet
  if (is.null(prefix)) {
    stop("Unknown font library '", lib, "' specified. Must be one of ",
         paste0('"', names(prefixes), '"', collapse = ", "))
  }

  # build the icon class (allow name to be null so that other functions
  # e.g. buildTabset can pass an explicit class value)
  iconClass <- ""
  if (!is.null(name))
    iconClass <- paste0(prefix, " ", prefix, "-", name)
  if (!is.null(class))
    iconClass <- paste(iconClass, class)

  iconTag <- tags$i(class = iconClass)

  # font-awesome needs an additional dependency (glyphicon is in bootstrap)
  if (lib == "font-awesome") {
    htmlDependencies(iconTag) <- htmlDependency(
      "font-awesome", "4.5.0", c(href="shared/font-awesome"),
      stylesheet = "css/font-awesome.min.css"
    )
  }

  iconTag
}

# Helper funtion to extract the class from an icon
iconClass <- function(icon) {
  if (!is.null(icon)) icon$attribs$class
}
ymd526442121/Rproject_shiny documentation built on May 4, 2019, 5:31 p.m.