access_img {accessrmd}

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")