tar_renv: Set up package dependencies for compatibility with 'renv'
In wlandau/targets: Dynamic Function-Oriented 'Make'-Like Declarative Pipelines

tar_renv

R Documentation

Set up package dependencies for compatibility with `renv`

Description

Write package dependencies to a script file (by default, named ⁠_targets_packages.R⁠ in the root project directory). Each package is written to a separate line as a standard library() call (e.g. library(package)) so renv can identify them automatically.

Usage

tar_renv(
  extras = c("bs4Dash", "crew", "gt", "markdown", "pingr", "rstudioapi", "shiny",
    "shinybusy", "shinyWidgets", "visNetwork"),
  path = "_targets_packages.R",
  callr_function = callr::r,
  callr_arguments = targets::tar_callr_args_default(callr_function),
  envir = parent.frame(),
  script = targets::tar_config_get("script")
)

Arguments

`extras`	Character vector of additional packages to declare as project dependencies.
`path`	Character of length 1, path to the script file to populate with `library()` calls.
`callr_function`	A function from `callr` to start a fresh clean R process to do the work. Set to `NULL` to run in the current session instead of an external process (but restart your R session just before you do in order to clear debris out of the global environment). `callr_function` needs to be `NULL` for interactive debugging, e.g. `tar_option_set(debug = "your_target")`. However, `callr_function` should not be `NULL` for serious reproducible work.
`callr_arguments`	A list of arguments to `callr_function`.
`envir`	An environment, where to run the target R script (default: `⁠_targets.R⁠`) if `callr_function` is `NULL`. Ignored if `callr_function` is anything other than `NULL`. `callr_function` should only be `NULL` for debugging and testing purposes, not for serious runs of a pipeline, etc. The `envir` argument of `tar_make()` and related functions always overrides the current value of `tar_option_get("envir")` in the current R session just before running the target script file, so whenever you need to set an alternative `envir`, you should always set it with `tar_option_set()` from within the target script file. In other words, if you call `tar_option_set(envir = envir1)` in an interactive session and then `tar_make(envir = envir2, callr_function = NULL)`, then `envir2` will be used.
`script`	Character of length 1, path to the target script file. Defaults to `tar_config_get("script")`, which in turn defaults to `⁠_targets.R⁠`. When you set this argument, the value of `tar_config_get("script")` is temporarily changed for the current function call. See `tar_script()`, `tar_config_get()`, and `tar_config_set()` for details about the target script file and how to set it persistently for a project.

Details

This function gets called for its side-effect, which writes package dependencies to a script for compatibility with renv. The generated file should not be edited by hand and will be overwritten each time tar_renv() is called.

The behavior of renv is to create and manage a project-local R library and keep a record of project dependencies in a file called renv.lock. To identify dependencies, renv crawls through code to find packages explicitly mentioned using library(), require(), or ::. However, targets manages packages in a way that hides dependencies from renv. tar_renv() finds package dependencies that would be otherwise hidden to renv because they are declared using the targets API. Thus, calling tar_renv this is only necessary if using tar_option_set() or tar_target() to use specialized storage formats or manage packages.

With the script written by tar_renv(), renv is able to crawl the file to identify package dependencies (with renv::dependencies()). tar_renv() only serves to make your targets project compatible with renv, it is still the users responsibility to call renv::init() and renv::snapshot() directly to initialize and manage a project-local R library. This allows your targets pipeline to have its own self-contained R library separate from your standard R library. See https://rstudio.github.io/renv/index.html for more information.

Value

Nothing, invisibly.

Performance

If you use renv, then overhead from project initialization could slow down tar_make() and friends. If you experience slowness, please make sure your renv library is on a fast file system. (For example, slow network drives can severely reduce performance.) In addition, you can disable the slowest renv initialization checks. After confirming at https://rstudio.github.io/renv/reference/config.html that you can safely disable these checks, you can write lines RENV_CONFIG_RSPM_ENABLED=false, RENV_CONFIG_SANDBOX_ENABLED=false, and RENV_CONFIG_SYNCHRONIZED_CHECK=false in your user-level .Renviron file. If you disable the synchronization check, remember to call renv::status() periodically to check the health of your renv project library.

Examples

tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
  tar_script({
    tar_option_set(packages = c("tibble", "qs"))
    list()
  }, ask = FALSE)
  tar_renv()
  writeLines(readLines("_targets_packages.R"))
})
tar_option_reset()

wlandau/targets documentation built on April 21, 2024, 6:04 p.m.