Run all the R scripts in a directory in the environment specified.
Usage
tar_source(
files = "R",
envir = targets::tar_option_get("envir"),
change_directory = FALSE
)Arguments
- files
Character vector of file and directory paths to look for R scripts to run. Paths must either be absolute paths or must be relative to the current working directory just before the function call.
- envir
Environment to run the scripts. Defaults to
tar_option_get("envir"), the environment of the pipeline.- change_directory
Logical, whether to temporarily change the working directory to the directory of each R script before running it.
Details
tar_source() is a convenient way to load R scripts
in _targets.R to make custom functions available to the pipeline.
tar_source() recursively looks for files ending
in .R or .r, and it runs each with
eval(parse(text = readLines(script_file, warn = FALSE)), envir).
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().
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 utilities:
tar_active(),
tar_backoff(),
tar_call(),
tar_cancel(),
tar_definition(),
tar_described_as(),
tar_envir(),
tar_group(),
tar_name(),
tar_path(),
tar_path_script(),
tar_path_script_support(),
tar_path_store(),
tar_path_target(),
tar_store()
Examples
if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) { # for CRAN
tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
# Running in tar_dir(), these files are written in tempdir().
dir.create("R")
writeLines("f <- function(x) x + 1", file.path("R", "functions.R"))
tar_script({
tar_source()
list(tar_target(x, f(1)))
})
tar_make()
tar_read(x) # 2
})
}