Load the return values of targets into the current environment
(or the environment of your choosing). For a typical target, the return
value lives in a file in _targets/objects/
. For dynamic files (i.e.
format = "file"
) the paths loaded in place of the values.
tar_load_everything()
is shorthand for tar_load(everything())
to load all targets.
Usage
tar_load(
names,
branches = NULL,
meta = tar_meta(targets_only = TRUE, store = store),
strict = TRUE,
silent = FALSE,
envir = parent.frame(),
store = targets::tar_config_get("store")
)
Arguments
- names
Names of the targets to load. You may supply
tidyselect
helpers likeany_of()
andstarts_with()
. Names are selected from the metadata in_targets/meta
, which may include errored targets.- branches
Integer of indices of the branches to load for any targets that are patterns.
- meta
Data frame of metadata from
tar_meta()
.tar_read()
with the default arguments can be inefficient for large pipelines because all the metadata is stored in a single file. However, if you calltar_meta()
beforehand and supply it to themeta
argument, then successive calls totar_read()
may run much faster.- strict
Logical of length 1, whether to error out if one of the selected targets is in the metadata but cannot be loaded. Set to
FALSE
to just load the targets in the metadata that can be loaded and skip the others.- silent
Logical of length 1. Only relevant when
strict
isFALSE
. Ifsilent
isFALSE
andstrict
isFALSE
, then a message will be printed if a target is in the metadata but cannot be loaded. However, load failures will not stop other targets from being loaded.- envir
Environment to put the loaded targets.
- store
Character of length 1, path to the
targets
data store. Defaults totar_config_get("store")
, which in turn defaults to_targets/
. When you set this argument, the value oftar_config_get("store")
is temporarily changed for the current function call. Seetar_config_get()
andtar_config_set()
for details about how to set the data store path persistently for a project.
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 data:
tar_crew()
,
tar_load_everything()
,
tar_load_raw()
,
tar_objects()
,
tar_pid()
,
tar_process()
,
tar_read_raw()
,
tar_read()
Examples
if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) { # for CRAN
tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
tar_script({
list(
tar_target(y1, 1 + 1),
tar_target(y2, 1 + 1),
tar_target(z, y1 + y2)
)
}, ask = FALSE)
tar_make()
ls() # Does not have "y1", "y2", or "z".
tar_load(starts_with("y"))
ls() # Has "y1" and "y2" but not "z".
tar_load(any_of("z"))
ls() # Has "y1", "y2", and "z".
})
}