Select a subset of targets in the _targets.R file
based on their custom descriptions.
tar_described_as(
described_as = NULL,
tidyselect = TRUE,
callr_function = callr::r,
callr_arguments = targets::tar_callr_args_default(callr_function),
envir = parent.frame(),
script = targets::tar_config_get("script")
)A tidyselect expression to select targets
based on their descriptions. For example,
described_as = starts_with("survival model") matches all
targets in the pipeline whose description arguments
of tar_target() start with the text string "survival model".
If TRUE, return a call to tidyselect::all_of()
identifying the selected targets, which can then be supplied to any
tidyselect-compatible namesargument of downstream functions like [tar_make()] and [tar_manifest()]. IfFALSE`, return a simple character vector of target names.
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.
A list of arguments to callr_function.
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.
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.
If tidyselect is TRUE, then tar_described_as() returns
a call to tidyselect::all_of() which can be supplied to the names
argument of functions like tar_manifest() and tar_make().
This allows functions like tar_manifest() and tar_make()
to focus on only the targets with the matching descriptions.
If tidyselect is FALSE, then tar_described_as() returns
a simple character vector of the names of all the targets in the
pipeline with matching descriptions.
Targets with empty descriptions are ignored.
Other utilities:
tar_active(),
tar_backoff(),
tar_call(),
tar_cancel(),
tar_definition(),
tar_envir(),
tar_format_get(),
tar_group(),
tar_name(),
tar_path(),
tar_path_script(),
tar_path_script_support(),
tar_path_store(),
tar_path_target(),
tar_source(),
tar_store(),
tar_unblock_process()
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)
list(
tar_target(b2, TRUE, description = "blue two"),
tar_target(b3, TRUE, description = "blue three"),
tar_target(g2, TRUE, description = "green two"),
tar_target(g3, TRUE, description = "green three"),
tar_target(g4, TRUE, description = "green three")
)
}, ask = FALSE)
tar_described_as(starts_with("green"), tidyselect = FALSE)
tar_make(names = tar_described_as(starts_with("green")))
tar_progress() # Only `g2`, `g3`, and `g4` ran.
})
}