tar_load_globals: Load globals for debugging, testing, and prototyping

In targets: Dynamic Function-Oriented 'Make'-Like Declarative Pipelines

Load globals for debugging, testing, and prototyping

Description

Load user-defined packages, functions, global objects, and settings defined in the target script file (default: ⁠_targets.R⁠). This function is for debugging, testing, and prototyping only. It is not recommended for use inside a serious pipeline or to report the results of a serious pipeline.

Usage

tar_load_globals(
  envir = parent.frame(),
  script = targets::tar_config_get("script")
)

Arguments

envir

Environment to source the target script (default: ⁠_targets.R⁠). Defaults to the calling environment.

script

Character of length 1, path to the target script file that defines the pipeline (⁠_targets.R⁠ by default). This path should be either an absolute path or a path relative to the project root where you will call tar_make() and other functions. When tar_make() and friends run the script from the current working directory. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

Details

This function first sources the target script file (default: ⁠_targets.R⁠) to loads all user-defined functions, global objects, and settings into the current R process. Then, it loads all the packages defined in tar_option_get("packages") (default: (.packages())) using library() with lib.loc defined in tar_option_get("library") (default: NULL).

Value

NULL (invisibly).

Storage access

Several functions like tar_make(), tar_read(), tar_load(), tar_meta(), and tar_progress() read or modify the local data store of the pipeline. The local data store is in flux while a pipeline is running, and depending on how distributed computing or cloud computing is set up, not all targets can even reach it. So please do not call these functions from inside a target as part of a running pipeline. The only exception is literate programming target factories in the tarchetypes package such as tar_render() and tar_quarto().

See Also

Other debug: tar_traceback(), tar_workspace(), tar_workspaces()

Examples

if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) { # for CRAN
tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
tar_script({
  library(targets)
  library(tarchetypes)
  tar_option_set(packages = "callr")
  analyze_data <- function(data) {
    summary(data)
  }
  list(
    tar_target(x, 1 + 1),
    tar_target(y, 1 + 1)
  )
}, ask = FALSE)
tar_load_globals()
print(analyze_data)
print("callr" %in% (.packages()))
})
}

targets documentation built on Oct. 3, 2024, 1:11 a.m.