tar_branches: Reconstruct the branch names and the names of their...

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

Reconstruct the branch names and the names of their dependencies.

Description

Given a branching pattern, use available metadata to reconstruct branch names and the names of each branch's dependencies. The metadata of each target must already exist and be consistent with the metadata of the other targets involved.

Usage

tar_branches(
  name,
  pattern = NULL,
  script = targets::tar_config_get("script"),
  store = targets::tar_config_get("store")
)

Arguments

name	Symbol, name of the target.
pattern	Language to define branching for a target (just like in tar_target()) or NULL to get the pattern from the targets pipeline script specified in the script argument (default: ⁠_targets.R⁠).
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 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.
store	Character of length 1, path to the targets data store. Defaults to tar_config_get("store"), which in turn defaults to ⁠_targets/⁠. When you set this argument, the value of tar_config_get("store") is temporarily changed for the current function call. See tar_config_get() and tar_config_set() for details about how to set the data store path persistently for a project.

Details

The results from this function can help you retroactively figure out correspondences between upstream branches and downstream branches. However, it does not always correctly predict what the names of the branches will be after the next run of the pipeline. Dynamic branching happens while the pipeline is running, so we cannot always know what the names of the branches will be in advance (or even how many there will be).

Value

A tibble with one row per branch and one column for each target (including the branched-over targets and the target with the pattern.)

See Also

Other branching: tar_branch_index(), tar_branch_names(), tar_pattern()

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(x, seq_len(2)),
    tar_target(y, head(letters, 2)),
    tar_target(z, head(LETTERS, 2)),
    tar_target(dynamic, c(x, y, z), pattern = cross(z, map(x, y)))
  )
}, ask = FALSE)
tar_make()
tar_branches(dynamic)
tar_branches(dynamic, pattern = cross(z, map(x, y)))
})
}

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