Render a markdown document as a boxed grid grob

Draws a markdown document (headings, paragraphs, lists, task lists, quotes, code, tables, rules and images) inside an optional box. Text wraps to width, and math goes between $...$ . Everything markdown_grob() supports works inside each block.

Usage

markdown_box_grob(
  md,
  x = grid::unit(0.5, "npc"),
  y = grid::unit(0.5, "npc"),
  width = grid::unit(1, "npc"),
  height = NULL,
  hjust = 0.5,
  vjust = 0.5,
  halign = 0,
  valign = 1,
  padding = NULL,
  margin = NULL,
  box_gp = NULL,
  r = NULL,
  style = NULL,
  name = NULL,
  gp = grid::gpar(),
  vp = NULL
)

Arguments

md: Markdown, as a character string.
x, y: Position of the box.
width: Width of the box. NULL fits the box to its content, with no wrapping.
height: Height of the box. NULL (default) fits the content.
hjust, vjust: Justification of the box about x and y.
halign: Alignment of blocks in the box: 0 left (default), 0.5 centre, 1 right.
valign: Vertical alignment of the content when height leaves room: 1 top (default), 0 bottom.
padding, margin: A grid::unit() of length 1, or 4 for top, right, bottom and left. Padding is inside the box, margin outside. NULL (default) uses the style's body rule.
box_gp: Fill and border of the box, such as gpar(fill = "grey95", col = "black"). NULL (default) uses the style's body rule, and draws no box if it has none.
r: Corner radius. NULL (default) uses the style's body rule.
style: A markdown_style(), CSS text, or a path to a .css file. NULL (default) uses latex_options("markdown_style"), if set.
name: Grob name.
gp: Graphical parameters for the text. fontsize also scales the spacing between blocks.
vp: A viewport. If given, x, y, width, height, hjust and vjust are ignored.

Value

A grob of class "markdownbox".

Details

A table that is too wide for the box wraps its widest columns; table-layout: fixed gives the columns equal widths instead. Code lines do not wrap.

An image on its own line is a block, scaled down to fit; an image inside a sentence is inline. Images must be local PNG, JPEG or SVG files, and need the png or jpeg package, or rsvg and grImport2 for SVG. An image that cannot be drawn is an error.

Styling

style sets the look of each tag:

markdown_box_grob(md, style = markdown_style(
  h1         = md_style(color = "steelblue", font_size = 2),
  blockquote = md_style(border_left = "3px solid grey60")
))

Or the same as CSS, as text or a .css file:

markdown_box_grob(md, style = "
  h1 { color: steelblue; font-size: 2rem }
  blockquote { border-left: 3px solid grey60 }
")

To style one part, wrap it in a <div> with a class or style, with blank lines around the tags:

<div class="note">

## This heading only

</div>

<span class="..."> works the same inside a line. See markdown_style() for tag names and md_style() for properties.

Examples

# \donttest{
  md <- paste(
    "# Results", "",
    "The slope is $\\beta_1$ with *p* < 0.001.", "",
    "- first point", "- second point",
    sep = "\n"
  )
  grid::grid.newpage()
  grid::grid.draw(markdown_box_grob(
    md,
    width = grid::unit(4, "in"),
    padding = grid::unit(8, "pt"),
    box_gp = grid::gpar(fill = "grey95", col = "grey40")
  ))

# }