Paths to images produced by magick gets absolute paths

[LDalby]

This seem related to #1027, but to be honest I'm not entirely sure where the issue is.

I have an article in a package with a pkgdown site. When I call pkgdown::build_site() the images are shown correctly in the rendered html, but when inspecting the images I can see that the path are absolute. In contrast the plots produced using base plot (or ggplot2) have the correct, relative paths. When the pkgdown site is shown in its final location the magick images are then missing because the png can't be found.

Not sure how to produce a proper reprex for this as it involves building the site. To create the content below I started a new project in RStudio as a package and called:

1. usethis::use_pkgdown()
2. usethis::use_article("imgpathdebug")
3. pkgdown::build_site()

Below is a minimal rmd (the content of the "imgpathdebug" article mentioned in 2) ) which when rendered via pkgdown::build_site() will produce the two different paths shown in the screen shot below:

---
title: "imgpathdebug"
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r setup}
library(magick)
```

```{r}
plot(1:10, 1:10)
```

```{r}
frink <- image_read("https://jeroen.github.io/images/frink.png")
print(frink)
```

Session info

sessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value
#>  version  R version 4.3.1 (2023-06-16)
#>  os       macOS Ventura 13.5
#>  system   aarch64, darwin20
#>  ui       X11
#>  language (EN)
#>  collate  en_US.UTF-8
#>  ctype    en_US.UTF-8
#>  tz       Europe/Copenhagen
#>  date     2023-08-22
#>  pandoc   3.1.1 @ /Applications/RStudio.app/Contents/Resources/app/quarto/bin/tools/ (via rmarkdown)
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version date (UTC) lib source
#>  cli           3.6.1   2023-03-23 [1] CRAN (R 4.3.0)
#>  digest        0.6.33  2023-07-07 [1] CRAN (R 4.3.0)
#>  evaluate      0.21    2023-05-05 [1] CRAN (R 4.3.0)
#>  fastmap       1.1.1   2023-02-24 [1] CRAN (R 4.3.0)
#>  fs            1.6.3   2023-07-20 [1] CRAN (R 4.3.0)
#>  glue          1.6.2   2022-02-24 [1] CRAN (R 4.3.0)
#>  htmltools     0.5.6   2023-08-10 [1] CRAN (R 4.3.0)
#>  knitr         1.43    2023-05-25 [1] CRAN (R 4.3.0)
#>  lifecycle     1.0.3   2022-10-07 [1] CRAN (R 4.3.0)
#>  magrittr      2.0.3   2022-03-30 [1] CRAN (R 4.3.0)
#>  purrr         1.0.2   2023-08-10 [1] CRAN (R 4.3.0)
#>  R.cache       0.16.0  2022-07-21 [1] CRAN (R 4.3.0)
#>  R.methodsS3   1.8.2   2022-06-13 [1] CRAN (R 4.3.0)
#>  R.oo          1.25.0  2022-06-12 [1] CRAN (R 4.3.0)
#>  R.utils       2.12.2  2022-11-11 [1] CRAN (R 4.3.0)
#>  reprex        2.0.2   2022-08-17 [1] CRAN (R 4.3.0)
#>  rlang         1.1.1   2023-04-28 [1] CRAN (R 4.3.0)
#>  rmarkdown     2.24    2023-08-14 [1] CRAN (R 4.3.0)
#>  rstudioapi    0.15.0  2023-07-07 [1] CRAN (R 4.3.0)
#>  sessioninfo   1.2.2   2021-12-06 [1] CRAN (R 4.3.0)
#>  styler        1.10.1  2023-06-05 [1] CRAN (R 4.3.0)
#>  vctrs         0.6.3   2023-06-14 [1] CRAN (R 4.3.0)
#>  withr         2.5.0   2022-03-03 [1] CRAN (R 4.3.0)
#>  xfun          0.40    2023-08-09 [1] CRAN (R 4.3.0)
#>  yaml          2.3.7   2023-01-23 [1] CRAN (R 4.3.0)
#> 
#>  [1] /Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/library
#> 
#> ──────────────────────────────────────────────────────────────────────────────

Is there a way to fix this?

[hadley]

I think this is a problem either with magick:::`knit_print.magick-image`, or possible the way that pkgdown builds rmarkdown files using an intermediates_dir. But it looks like we already have code to convert paths to relative in tweak_rmarkdown_html() so maybe there's something more I can do there.

Ah the problem is that it's not an absolute path here, but a weird relative path:
../../docs/dev/articles/test/widgets_files/figure-html/unnamed-chunk-2-1.png. Looking at what a regular plot generates, this path should be more like widgets_files/figure-html/unnamed-chunk-2-1.png.

[hadley]

Interestingly if I set options(knitr.graphics.rel_path = FALSE), the problem goes away. So maybe I should always do that?