Select a subset of targets in the _targets.R
file
based on their custom descriptions.
Usage
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")
)
Arguments
- described_as
A
tidyselect
expression to select targets based on their descriptions. For example,described_as = starts_with("survival model")
matches all targets in the pipeline whosedescription
arguments oftar_target()
start with the text string"survival model"
.- tidyselect
If
TRUE
, return a call totidyselect::all_of()
identifying the selected targets, which can then be supplied to anytidyselect
-compatible namesargument of downstream functions like [tar_make()] and [tar_manifest()]. If
FALSE`, return a simple character vector of target names.- callr_function
A function from
callr
to start a fresh clean R process to do the work. Set toNULL
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 beNULL
for interactive debugging, e.g.tar_option_set(debug = "your_target")
. However,callr_function
should not beNULL
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
) ifcallr_function
isNULL
. Ignored ifcallr_function
is anything other thanNULL
.callr_function
should only beNULL
for debugging and testing purposes, not for serious runs of a pipeline, etc.The
envir
argument oftar_make()
and related functions always overrides the current value oftar_option_get("envir")
in the current R session just before running the target script file, so whenever you need to set an alternativeenvir
, you should always set it withtar_option_set()
from within the target script file. In other words, if you calltar_option_set(envir = envir1)
in an interactive session and thentar_make(envir = envir2, callr_function = NULL)
, thenenvir2
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 oftar_config_get("script")
is temporarily changed for the current function call. Seetar_script()
,tar_config_get()
, andtar_config_set()
for details about the target script file and how to set it persistently for a project.
Value
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.
See also
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()
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)
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.
})
}