Write the project manifest

generate_manifest() reads the accumulator written by save_output() over the course of an analysis, collapses it to one row per output file, and writes project-manifest.json describing every artifact the project produced.

Usage

generate_manifest(
  output_dir = "output",
  filename = "project-manifest.json",
  overwrite = FALSE
)

Arguments

output_dir

Character. Directory containing accumulator.csv and receiving the manifest. Defaults to "output".

filename

Character. Name of the manifest file. Defaults to "project-manifest.json".

overwrite

Logical. When FALSE (default), an existing manifest at that path is an error rather than being replaced.

Value

The path to the manifest, invisibly.

Details

The manifest records execution_context and generated_at once at the top level, followed by an artifacts array with one entry per output file, ordered chronologically. Context and generation time are facts about the run as a whole rather than about any individual artifact, so they are not repeated per entry. Package and R versions are deliberately absent: that is renv's job, and duplicating it here would create a second record to keep in sync.

Field names are toolero's own rather than RO-Crate vocabulary. The translation to @id, dateCreated, and the rest belongs in encapsulr::describe() as a thin mapping layer, so that toolero's public interface does not inherit a downstream package's data model.

Checksums are likewise excluded. RO-Crate defers fixity to BagIt and OCFL, and rocrateR::bag_rocrate() computes manifest-sha512.txt automatically at bagging time.

A missing accumulator is an error: no save was ever recorded, and an empty manifest would present that as a finished result. An accumulator holding no rows is different – the file exists, so the machinery was wired up – and produces an empty manifest with a warning.

The project manifest and the job manifest

This is the project manifest: a record of outputs from a computation that has already happened. It is distinct from the job manifest produced by write_by_group() and consumed by submitr::htc_gen_submit(), which lists inputs to a computation about to happen. The two are structurally different documents that happen to share a word, which is why this one defaults to project-manifest.json rather than manifest.json.

See also

save_output()

Examples

output_dir <- withr::local_tempdir()

save_output(
  object = mtcars,
  file_path = fs::path(output_dir, "mtcars.rds"),
  .f = saveRDS,
  output_dir = output_dir
)
#> ℹ Created the directory /tmp/RtmpAyNNfD/file4e547d0d57b5 to hold mtcars.rds.

generate_manifest(output_dir = output_dir)
#> ✔ Wrote /tmp/RtmpAyNNfD/file4e547d0d57b5/project-manifest.json describing 1
#>   artifact.