value_box: Value box

In bslib: Custom 'Bootstrap' 'Sass' Themes for 'shiny' and 'rmarkdown'

Value box

Description

An opinionated (card()-powered) box, designed for displaying a value and title. Optionally, a showcase can provide for context for what the value represents (for example, it could hold a bsicons::bs_icon(), or even a shiny::plotOutput()). Find examples and template code you can use to create engaging value boxes on the bslib website.

Usage

value_box(
  title,
  value,
  ...,
  showcase = NULL,
  showcase_layout = c("left center", "top right", "bottom"),
  full_screen = FALSE,
  theme = NULL,
  height = NULL,
  max_height = NULL,
  min_height = NULL,
  fill = TRUE,
  class = NULL,
  id = NULL,
  theme_color = deprecated()
)

value_box_theme(name = NULL, bg = NULL, fg = NULL)

showcase_left_center(
  width = 0.3,
  width_full_screen = "1fr",
  max_height = "100px",
  max_height_full_screen = 0.67
)

showcase_top_right(
  width = 0.4,
  width_full_screen = "1fr",
  max_height = "75px",
  max_height_full_screen = 0.67
)

showcase_bottom(
  width = "100%",
  width_full_screen = NULL,
  height = "auto",
  height_full_screen = "2fr",
  max_height = "100px",
  max_height_full_screen = NULL
)

Arguments

title, value	A string, number, or htmltools::tag() child to display as the title or value of the value box. The title appears above the value.
...	Unnamed arguments may be any htmltools::tag() children to display below value. Named arguments become attributes on the containing element.
showcase	A htmltools::tag() child to showcase (e.g., a bsicons::bs_icon(), a plotly::plotlyOutput(), etc).
showcase_layout	One of "left center" (default), "top right" or "bottom". Alternatively, you can customize the showcase layout options with the showcase_left_center(), showcase_top_right(), or showcase_bottom() functions. Use the options functions when you want to control the height or width of the showcase area.
full_screen	If TRUE, an icon will appear when hovering over the card body. Clicking the icon expands the card to fit viewport size.
theme	The name of a theme for the value box, or a theme constructed with value_box_theme(). The theme names provide a convenient way to use your app's Bootstrap theme colors as the foreground or background colors of the value box. See below for more details on the provided themes. For more control, you can create your own theme with value_box_theme() where you can pass foreground and background colors directly. See the Themes section for more details.
max_height	The maximum height of the value_box() or the showcase area when used in a ⁠showcase_layout_*()⁠ function. Can be any valid CSS unit (e.g., max_height="200px").
min_height	The minimum height of the values box. Can be any valid CSS unit (e.g., min_height="200px").
fill	Whether to allow the value box to grow/shrink to fit a fillable container with an opinionated height (e.g., page_fillable()).
class	Utility classes for customizing the appearance of the summary card. Use ⁠bg-*⁠ and ⁠text-*⁠ classes (e.g, "bg-danger" and "text-light") to customize the background/foreground colors.
id	Provide a unique identifier for the card() or value_box() to report its full screen state to Shiny. For example, using id = "my_card", you can observe the card's full screen state with input$my_card_full_screen.
theme_color	Use theme instead.
name	The name of the theme, e.g. "primary", "danger", "purple".
bg, fg	The background and foreground colors for the theme. If only bg is provided, then the foreground color is automatically chosen from ⁠$black⁠ or ⁠$white⁠ to provide the best contrast with the background color.
width, width_full_screen, height, height_full_screen	one of the following: A proportion (i.e., a number between 0 and 1) of available width or height to allocate to the showcase. A valid CSS unit defining the width or height of the showcase column, or a valid value accepted by the grid-template-columns (width) or grid-template-rows (height) CSS property to define the width or height of the showcase column or row. Accepted values in the second category are "auto", "min-content", "max-content", a fractional unit (e.g. ⁠2fr⁠), or a minmax() function (e.g., ⁠minmax(100px, 1fr)⁠).
max_height_full_screen	A proportion (i.e., a number between 0 and 1) or any valid CSS unit defining the showcase max_height in a full screen card.

Build-a-Box App

Explore all of the value_box() options and layouts interactively with the Build-a-Box app, available online thanks to shinyapps.io. Or, you can run the app locally with:

# shiny >= 1.8.1
shiny::runExample("build-a-box", package = "bslib")

# shiny < 1.8.1
shiny::runApp(system.file("examples-shiny", "build-a-box", package = "bslib"))

Themes

The appearance of a value_box() can be controlled via the theme argument in one of two ways:

1. a character value describing the theme, such as theme = "primary" or theme = "blue"; or

2. theme = value_box_theme() to create a custom theme.

We recommend using named themes for most value boxes (the first approach), because these themes will automatically match your Bootstrap theme.

Named themes

Bootstrap provides a list of theme colors, with semantic names like "primary", "secondary", "success", "danger", etc. You can set theme to one of these names to use the corresponding theme color as the background color of your value box.

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "primary"
)

Bootstrap's theme colors are drawn from a second color list that includes variations on several main colors, named literally. These colors include "blue", "purple", "pink", "red", "orange", "yellow", "green", "teal", and "cyan".

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "teal"
)

Background colors

If the theme or color name is provided without any prefix, the color will be used for the background of the value box. You can also explicitly prefix the theme or color name with ⁠bg-⁠ to indicate that it should apply to the value box background. When the theme sets the background color, either black or white is chosen automatically for the text color using Bootstrap's color contrast algorithm.

As before, you can reference semantic theme color names or literal color names.

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "bg-success"
)

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "bg-purple"
)

Foreground colors

To set only the foreground colors of the value box, you can prefix the theme or color name with ⁠text-⁠. This changes the text color without affecting the background color.

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "text-success"
)

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "text-purple"
)

Occasionally you may want to adjust use both background and foreground themes on your value box. To achieve this, set theme to one of the theme names and use class for the complementary style. The example below uses theme = "purple" (which could also be "bg-purple") for a purple background, and class = "text-light" for light-colored text.

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "purple",
  class = "text-light"
)

Gradient backgrounds

For a vibrant and attention-grabbing effect, bslib provides an array of gradient background options. Provide theme with a theme name in the form bg-gradient-{from}-{to}, where {from} and {to} are named main colors, e.g. bg-gradient-indigo-blue.

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = "bg-gradient-indigo-blue"
)

Custom colors

Finally, for complete customization, you can use value_box_theme() to create a custom theme. This function takes arguments bg and fg to set the background and foreground colors, respectively. Like with the ⁠bg-⁠ theme names, if only bg is provided, value_box_theme() will choose an appropriate light or dark color for the text color.

value_box(
  title = "Customer lifetime value",
  value = "$5,000",
  showcase = bsicons::bs_icon("bank2"),
  theme = value_box_theme(bg = "#e6f2fd", fg = "#0B538E"),
  class = "border"
)

Note that value_box_theme() optionally takes a theme name, which can be helpful if you want to use a named theme and modify the default bg or fg colors of that theme.

value_box_theme(name = "orange", bg = "#FFFFFF")
value_box_theme(name = "text-danger", fg = "#FFB6C1")

Also note that bg/fg must be CSS colors, not Bootstrap theme or color names. This means that theme = "purple" will use your Bootstrap theme's purple color, and bg = "purple" will use the CSS color for purple, i.e. "#800080".

Showcase Layouts

Use the showcase argument to add a plot or icon to your value_box(). There are three layouts available: "left center", "top right", and "bottom". Set showcase to the name of the layout you'd like, or use the showcase_left_center(), showcase_top_right(), or showcase_bottom() helper functions to customize the showcase area's size.

If you're using a plot as your showcase, you may also want to set fullscreen = TRUE so that your users can expand the value box into a full screen card. See the value box article for more details.

Left-center showcase

The "left center" showcase layout is the default, and is perfect for an icon or a small plot. This layout works best for short value boxes.

value_box(
  title = "Energy consumption",
  value = "345 kwh/month",
  showcase = bsicons::bs_icon("ev-station-fill")
)

Top-right showcase

The "top right" showcase layout places the icon or plot in the upper right corner of the value box. This layout works best for medium-height to square value boxes.

value_box(
  title = "Energy consumption",
  value = "345 kwh/month",
  showcase = bsicons::bs_icon("ev-station-fill"),
  showcase_layout = "top right"
)

Bottom showcase

Finally, the "bottom" showcase layout is perfect for full-bleed plots. This layout places the plot below the title and value, with the plot taking up the full width of the bottom half.

Try this layout with sparkline-style plots. These can be a little tricky to set up, so be sure to check out the Expandable sparklines section of the value boxes article on the bslib website. In this example, we've created a sparkline plot using base R graphics, which isn't generally recommended.

Code for a sparkline plot with base R

set.seed(4242)

random_sparkline_plot <- function() {
  timeseries <- cumsum(runif(100, -2, 2))
  x_axis <- seq_along(timeseries)
  x_lim <- c(1, length(timeseries))
  y_lim <- range(timeseries) + c(-2, 0)

  par(mar = c(0, 0, 0, 0))

  # Set up the plot area
  plot(
    timeseries, type = "n",
    axes = FALSE, frame.plot = FALSE,
    ylim = y_lim, xlim = x_lim,
    ylab = "",    xlab = "",
    yaxs = "i",   xaxs = "i",
  )

  # Add the sparkline line
  lines(timeseries, type = "l", pch = NA, col = "#0B538E", lwd = 3)

  # Create polygon coordinates for shading
  polygon_x <- c(1, x_axis, length(timeseries))
  polygon_y <- c(min(y_lim), timeseries, min(y_lim))

  # Add shading under the line
  polygon(polygon_x, polygon_y, col = "#e6f2fd", border = NA)
}

sparkline_plot <- function() {
  as_fill_item(
    htmltools::plotTag(
      random_sparkline_plot(),
      width = 500,
      height = 125,
      suppressSize = "xy",
      alt = paste(
        "A sparkline plot with a randomly-generated timeseries.",
        "The timeseries starts high and ends low, with lots of variation."
      )
    )
  )
}

value_box(
  title = "Energy consumption",
  value = "345 kwh/month",
  showcase = sparkline_plot(),
  showcase_layout = "bottom"
)

References

Value boxes are featured on the bslib website in a few articles:

• Value boxes

• Build-a-Box App

• Get Started: Dashboards

See Also

Value boxes are a specialized form of a card() component.

layout_columns() and layout_column_wrap() help position multiple value boxes into columns and rows.

Other Components: accordion(), card(), popover(), tooltip()

Examples

library(htmltools)

value_box(
  "KPI Title",
  h1(HTML("$1 <i>Billion</i> Dollars")),
  span(
    bsicons::bs_icon("arrow-up"),
    " 30% VS PREVIOUS 30 DAYS"
  ),
  showcase = bsicons::bs_icon("piggy-bank"),
  theme = "success"
)

bslib documentation built on Sept. 11, 2024, 7:49 p.m.