access_img: Produce an accessible image or chart.

In accessrmd: Improving the Accessibility of 'rmarkdown' Documents

Produce an accessible image or chart.

Description

Reads in an image and produces the HTML structure expected by web accessibility checkers such as WAVE. Also works as a wrapper around ggplot2 charts.

Usage

access_img(
  img = last_plot(),
  alt = NULL,
  wid = NULL,
  ht = NULL,
  dpi = 300,
  css_class = NULL,
  css_id = NULL
)

Arguments

img	The image to include as accessible HTML. Defaults to 'ggplot2::last_plot()'. Can be replaced with an image written to disc.
alt	A character string describing the image for screen reader accessibility.
wid	Width of the image in pixels.
ht	Height of the image in pixels.
dpi	Resolution. Please see ?ggplot2::ggsave() for details.
css_class	Specify a css class selector for the image.
css_id	Specify a css ID selector for the image.

Value

Inline HTML with the necessary structure for screen reader accessibility.

Examples

# create a ggplot2 chart
ggplot(pressure, aes(temperature, pressure)) +
  geom_point()

# Use 'access_img()' to render the chart with alt text
access_img(alt = "Vapor Pressure of Mercury as a Function of Temperature")

# Create a png.
file.create(tempfile("some_img", fileext = ".png"))

# Read it from disk and include alt text
access_img("some_img.png", alt = "Some meaningful alt text")

accessrmd documentation built on May 3, 2022, 5:07 p.m.