Generating better reprex with gt

[jthomasmock]

Prework

• [x] Read and abide by gt's code of conduct and contributing guidelines.
• [x] Search for duplicates among the existing issues (both open and closed).

Proposal

I create a LOT Of reprex examples with gt tables. The rendered output in the viewer comes out "ok" but doesn't accurately represent the gt table even with venue = "html". It also creates a very unwieldy and long output that is primarily raw HTML/CSS.

In my mind, when calling reprex on a gt table, it should almost always actually do:

data %>%
  some_gt_code() %>%
  gtsave("temp.png")

At the reprex level, it is rendering via rmarkdown but not including the CSS in the rendered output but rather as raw CSS:

library(gt)

head(mtcars) %>%
  gt()

reprex output:

actual gt output which is stylized very differently.

reprex and potential solutions

Please include a minimal reproducible example (AKA a reprex). If you've never heard of a reprex before, start by reading https://www.tidyverse.org/help/#reprex.

library(gt)

head(mtcars) %>%
  gt()

and then call reprex::reprex_html() or reprex::reprex()

While the table itself doesn't appear correctly, it also adds a massive amount of CSS classes which are captured in the details tag below.

LONG output

library(gt)

head(mtcars) %>%
  gt()

mpg	cyl	disp	hp	drat	wt	qsec	vs	am	gear	carb
21.0	6	160	110	3.90	2.620	16.46	0	1	4	4
21.0	6	160	110	3.90	2.875	17.02	0	1	4	4
22.8	4	108	93	3.85	2.320	18.61	1	1	4	1
21.4	6	258	110	3.08	3.215	19.44	1	0	3	1
18.7	8	360	175	3.15	3.440	17.02	0	0	3	2
18.1	6	225	105	2.76	3.460	20.22	1	0	3	1

^{Created on 2022-06-17 by the reprex package (v2.0.1)}

A workaround I do commonly is save the table out to an image instead via gt::gtsave() which adds the verbatim table as an image tag and is much more useful to provide in bug reports/reprex. A reprex of this style is seen below. However, the addition of gtsave() code is "unnecessary" to the minimal functionality of the code and more about the output.

The vast majority of the reprex or bug reports I see from users submitting gt examples only report the code and MAYBE a manual screenshot of varying quality as not everyone thinks to do the gtsave() hack.

Would it be possible to have a method in gt so that when gt is called in the context of a reprex it would generate the image output or at least suggest to users that they include that in their code?

library(gt)

head(mtcars) %>%
  gt() %>%
  gtsave("out.png")

^{Created on 2022-06-17 by the reprex package (v2.0.1)}

[jthomasmock]

I believe this could be accomplished via a custom print method when rendering in the context of a reprex.

https://bookdown.org/yihui/rmarkdown-cookbook/opts-render.html

Or possibly some interaction with screenshot.force = TRUE, although that is currently focused on HTML widgets.

https://bookdown.org/yihui/bookdown/html-widgets.html#html-widgets

[rich-iannone]

For this I think we need to upgrade webshot to webshot2 (in #621 ). But, definitely, better reprexes are needed from gt and I consider this an important issue.

[mrcaseb]

I have just been informed this issue existed because I have implemented this behavior in nflplotR. See https://nflplotr.nflverse.com/reference/gt_render_image.html

My idea was to have the gt output saved as png and plotted to the viewer through magick (because my package depends on magick anyways). @jthomasmock suggested knitr instead which also is working.

It's also not only about reprexes. It's about dynamically rendering tables in package examples (see example on my pkgdown site).

However, rendering the images in examples has a downside, as chromote keeps open connections which causes R CMD check errors. I bypass them by running the examples only if the relevant environment variable is set to false and do this in the pkgdown workflow.

[jthomasmock]

Dev gtExtras now has a gt_reprex_image() function, calling reprex::reprex() on the code below generates the following reprex:

head(mtcars) |> 
  gt::gt() |> 
  gtExtras::gt_plt_bar(mpg) |> 
  gtExtras::gt_reprex_image()

^{Created on 2023-02-27 by the reprex package (v2.0.1)}

In an ideal world, something like this could live in gt proper and perhaps have a method so that when reprex() is called on a gt pipeline, it automatically calls it?

Without this function, the output reprex is almost worthless 😭 as it would appear like this (in collapsed section below):

head(mtcars) |> 
  gt::gt() |> 
  gtExtras::gt_plt_bar(mpg)

mpg	cyl	disp	hp	drat	wt	qsec	vs	am	gear	carb
	6	160	110	3.90	2.620	16.46	0	1	4	4
	6	160	110	3.90	2.875	17.02	0	1	4	4
	4	108	93	3.85	2.320	18.61	1	1	4	1
	6	258	110	3.08	3.215	19.44	1	0	3	1
	8	360	175	3.15	3.440	17.02	0	0	3	2
	6	225	105	2.76	3.460	20.22	1	0	3	1

^{Created on 2023-02-27 by the reprex package (v2.0.1)}