Simplify conditional expressions involved in vignette evaluation

[IndrajeetPatil]

Preamble

To pass the "noSuggests" check, we use the recommended approach of evaluating vignettes conditional on availability of all soft/weak dependencies. But, currently, the way we do it is quite complex and difficult to discern and extend. We can simplify this significantly, as shown below.

Before

if (!requireNamespace("bayestestR", quietly = TRUE) ||
  !requireNamespace("httr", quietly = TRUE) || # needed for `insight::download_model()`
  !requireNamespace("rstanarm", quietly = TRUE) ||
  !requireNamespace("ggplot2", quietly = TRUE) ||
  !requireNamespace("brms", quietly = TRUE) ||
  !requireNamespace("logspline", quietly = TRUE) ||
  !requireNamespace("insight", quietly = TRUE)) {
  knitr::opts_chunk$set(eval = FALSE)
}

After

Note that adding or removing any of the needed deps is as simple as modifying the character vector of package names.

# `{httr}` is needed for `insight::download_model()`
pkgs <- c("bayestestR", "brms", "ggplot2", "httr", "insight", "logspline", "rstanarm")
successfully_loaded <- vapply(pkgs, requireNamespace, FUN.VALUE = logical(1L), quietly = TRUE)
can_evaluate <- all(successfully_loaded)

if (can_evaluate) {
  knitr::opts_chunk$set(eval = TRUE)
  vapply(pkgs, require, FUN.VALUE = logical(1L), quietly = TRUE, character.only = TRUE)
} else {
  knitr::opts_chunk$set(eval = FALSE)
}

Progress tracker:

• insight
• modelbased
• bayestestR
• effectsize
• parameters
• performance
• correlation
• report
• see
• datawizard
• easystats

[IndrajeetPatil]

For a reference, see my PR in {see} that does this simplification.

[mattansb]

In {effectsize} I've gone a slightly different route - instead of skipping all execution if one package is missing, just the relevant chinks are skipped. So I consider {effectsize} as closed on this issue.

[IndrajeetPatil]

@mattansb Sounds good to me!

Yes, this is relevant for the repo you are maintaining only if you are using the outlined pattern.

[rempsyc]

For a given vignette, for how many external packages is it worth changing? E.g., for a single package? Two packages? report has only one or two external packages per vignette.

(seems a bit overkill for a single package, going from 3 lines to 9 lines, so I haven't changed those yet)

[IndrajeetPatil]

For a given vignette, for how many external packages is it worth changing? E.g., for a single package? Two packages? report has only one or two external packages per vignette.

(seems a bit overkill for a single package, going from 3 lines to 9 lines, so I haven't changed those yet)

I think, for vignettes using more than one package, this makes sense.
Because if you need to use an additional package, modifying this code is as simple as extending the vector of package names.

[IndrajeetPatil]

bump