lt_export: Export an lt table to a file

In lt: Lightweight Tables via JSON Specs and JavaScript

Export an lt table to a file

Description

Save a table to disk. The output format is chosen from the file extension of output: .html writes an HTML table, .pdf writes a vector PDF, and any other extension writes a PNG. PDF and PNG are produced by rendering the table in a headless Chromium browser (via xfun::browser_print()).

Usage

lt_export(
  x,
  output = "lt.html",
  method = c("auto", "node", "browser", "raw"),
  css = TRUE,
  fragment = FALSE,
  tidy = FALSE,
  crop = TRUE,
  width = NULL,
  padding = 8,
  browser = NULL,
  ...
)

Arguments

x	An lt_tbl object.
output	Output file path. Its extension selects the format: .html, .pdf, or (otherwise) PNG. If NA, the HTML is returned as a string instead of being written to a file.
method	How to produce the HTML ⁠<table>⁠: "auto", "node", "browser", or "raw" (see Details). Applies only to .html output.
css	Whether to include the lt.css runtime stylesheet in the HTML output. User CSS from lt_css() is always included. Applies only to .html output.
fragment	If FALSE (default), wrap the HTML in a full HTML document; if TRUE, return only the table fragment. Applies only to .html output.
tidy	Whether to pretty-print the baked ⁠<table>⁠ with line breaks and indentation. Applies only to .html output baked by "node" or "browser" (ignored for method = "raw", which is a JavaScript spec).
crop	Whether to crop the PDF/PNG tightly to the table, removing the surrounding page whitespace. This adds a preliminary browser pass to measure the rendered table. Set to FALSE for the default full page. Cropping PNG output requires the magick package; without it, PNG falls back to the full page (with a warning).
width	The width of the table in CSS pixels. By default (NULL) it shrinks to the table's natural width. A smaller width wraps cell content; a larger one pads the table.
padding	Padding in CSS pixels to keep around the table when cropping. A single value (all sides) or a length-two vector c(vertical, horizontal).
browser	Path to the Chromium-based browser; passed to xfun::browser_print(). NULL (default) auto-detects.
...	Passed to xfun::browser_print() for PDF/PNG output.

Details

For .html output, method controls how the ⁠<table>⁠ is produced: "raw" writes the JavaScript-spec HTML, so the table is built in the browser by the lt.js runtime when the file is viewed; the other methods bake a static ⁠<table>⁠ up front by running lt.js once (via "node" in Node.js or "browser" in a headless Chromium browser; "auto" picks Node if available, else the browser), so the saved file needs no JavaScript to view. method, css, fragment, and tidy apply only to .html output.

Value

The output path, or (when output is NA) the HTML as a string.

Global option

When the option lt.lt_static is set to a list of arguments (e.g., options(lt.lt_static = list(css = FALSE))), the knit_print and record_print methods emit the same static HTML table as lt_export(x, "*.html") (using those arguments as method/css/fragment) instead of the default JavaScript-based spec. This is useful for output formats that support raw HTML but cannot run JavaScript (e.g., GitHub Flavored Markdown).

Examples

tbl = lt(head(mtcars))

# HTML with the JavaScript spec (table built by lt.js when viewed)
lt_export(tbl, NA, method = 'raw')  # character output
f1 = tempfile(fileext = '.html')
lt_export(tbl, f1, method = 'raw')  # file output

# Bake a static <table> (needs Node.js or a headless browser).
if (lt:::can_bake())
  lt_export(tbl, NA, method = 'auto', fragment = TRUE, css = FALSE)

# PDF / PNG are rendered in a headless browser and cropped to the table.
f2 = tempfile(fileext = '.pdf')
f3 = tempfile(fileext = '.png')
if (lt:::has_browser()) {
  lt_export(tbl, f2)
  lt_export(tbl, f3, width = 400)
}

unlink(c(f1, f2, f3))

lt documentation built on July 10, 2026, 1:09 a.m.