web_image
Helper function for adding an image from the web
Description
We can flexibly add a web image inside of a table with web_image()
function. The function provides a convenient way to generate an HTML fragment
with an image URL. Because this function is currently HTML-based, it is only
useful for HTML table output. To use this function inside of data cells, it
is recommended that the text_transform() function is used. With that
function, we can specify which data cells to target and then include a
web_image() call within the required user-defined function (for the fn
argument). If we want to include an image in other places (e.g., in the
header, within footnote text, etc.) we need to use web_image() within the
html() helper function.
Usage
web_image(url, height = 30)
Arguments
url |
A url that resolves to an image file. |
height |
The absolute height (px) of the image in the table cell. |
Details
By itself, the function creates an HTML image tag, so, the call
web_image("http://some.web.site/image.png") evaluates to:
<img src=\"http://some.web.site/image.png\" style=\"height:30px;\">
where a height of 30px is a default height chosen to work well within the
heights of most table rows.
Value
A character object with an HTML fragment that can be placed inside of a cell.
Figures
Function ID
8-1
See Also
Other Image Addition Functions:
ggplot_image(),
local_image(),
test_image()
Examples
# Get the PNG-based logo for the R
# Project from an image URL
r_png_url <-
"https://www.r-project.org/logo/Rlogo.png"
# Create a tibble that contains heights
# of an image in pixels (one column as a
# string, the other as numerical values),
# then, create a gt table; use the
# `text_transform()` function to insert
# the R logo PNG image with the various
# sizes
tab_1 <-
dplyr::tibble(
pixels = px(seq(10, 35, 5)),
image = seq(10, 35, 5)
) %>%
gt() %>%
text_transform(
locations = cells_body(vars(image)),
fn = function(x) {
web_image(
url = r_png_url,
height = as.numeric(x)
)
}
)
# Get the SVG-based logo for the R
# Project from an image URL
r_svg_url <-
"https://www.r-project.org/logo/Rlogo.svg"
# Create a tibble that contains heights
# of an image in pixels (one column as a
# string, the other as numerical values),
# then, create a gt table; use the
# `tab_header()` function to insert
# the R logo SVG image once in the title
# and five times in the subtitle
tab_2 <-
dplyr::tibble(
pixels = px(seq(10, 35, 5)),
image = seq(10, 35, 5)
) %>%
gt() %>%
tab_header(
title = html(
"<strong>R Logo</strong>",
web_image(
url = r_svg_url,
height = px(50)
)
),
subtitle = html(
web_image(
url = r_svg_url,
height = px(12)
) %>%
rep(5)
)
)