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Restore a snapshot's grading state

Source: R/snapshots.R
snapshot_restore.Rd

Writes a snapshot's rubric and marks (and optionally its template) back into the project database, undoing every change made since. An automatic snapshot of the current state is taken first, so a restore can itself be undone. Everything is written in one transaction: the template is stored, each chosen question's rubric items, groups and scoring are put back in place by id (an item the snapshot knows keeps its id, and with it every repository's recorded selections of it; items and groups the snapshot does not have are removed), and each chosen repository's selections and comments are set to the snapshot's, matched by the item ids the snapshot carries. Pairs with grading activity the snapshot did not record are cleared. The restored scores are then recomputed and compared with the scores the snapshot recorded; a mismatch aborts and rolls everything back.

Usage

snapshot_restore(
  id,
  project = ".",
  part = c("rubric", "marks"),
  question = NULL,
  repo = NULL,
  summary = NULL
)

Arguments

id

The snapshot: its id, a unique prefix of it, a unique label, "latest", or a non-positive integer counting back from the latest (0 is the latest, -1 the one before it).

project

Path to the project directory. Defaults to the working directory.

part

Which parts to restore: any of "rubric", "marks", "template". Defaults to the rubric and the marks.

question

Optional character vector of question names to restore (rubric and marks). Defaults to every question in the snapshot.

repo

Optional character vector of repository names whose marks to restore. Defaults to every repository of the project.

summary

Optional summary recorded on the automatic pre-restore snapshot: why the restore was needed.

Value

Invisibly, a list with snapshot_id (the restored snapshot) and pre_restore (the id of the snapshot taken before restoring, or NULL when the state was already recorded).

Details

Restoring the rubric alone keeps every repository's selections (of the items the snapshot still has), and restoring the marks alone aborts when the snapshot's selections name items the current rubric lacks, so the default restores both and a partial restore warns. question and repo narrow the restore ("undo the review for Q1c only", "for one student only"); repositories outside repo are left exactly as they are, and only the restored repositories are checked against the recorded scores. Without repo, every repository under the project's repos directory is restored, including repositories graded only after the snapshot, whose grading is cleared. Clearing appends deselection and empty-comment events (the grading tables are append-only logs), so a cleared pair still counts as having grading activity for marks_import()'s default skip; pass overwrite = TRUE to re-mark it. Repositories in the snapshot that no longer exist under the repos directory are skipped with a warning. A question the snapshot has that is not in the current template aborts unless "template" is among the parts. A question renamed since the snapshot is matched by its question id and restored under its current name.

See also

snapshot_create(), snapshot_diff()

Examples

if (FALSE) { # \dontrun{
snapshot_restore("Before review", project = "hw01",
  summary = "The review's Q1c severities were wrong; going back to re-do them.")

# Only one question
snapshot_restore("Before review", project = "hw01", question = "Q1c")
} # }