Pass draft to collection beforeChange and beforeValidate hooks

[fabioquarantini]

Problem

A collection beforeChange hook cannot tell a draft save from an unpublish.

Both reach the hook with data._status === 'draft': on a draft save updateDocument rewrites data._status to 'draft' before the hooks run, and originalDoc is the latest version rather than the published document. From inside the hook the two calls look identical. The only hook that knows whether the main document is about to be written is beforeOperation, which receives args.draft.

Why it matters

A hook that protects what the site serves has to let draft saves through and block unpublishes. Our case: pages have nested URLs (/parent/child), so a parent must not be unpublished while it still has published children. Saving a draft of the parent is fine, because the main document is untouched; unpublishing it is not.

Today the only way is a beforeOperation hook that copies args.draft into req.context, mirroring Payload's own condition (draft && hasDraftsEnabled && data._status !== 'published'), plus a beforeChange hook that reads it back. That is two hooks that only work when mounted together, and a copy of an internal rule that can drift on upgrade.

Proposal

Pass the value Payload already computes to the collection beforeValidate and beforeChange hooks:

beforeChange: [
  ({ data, draft, originalDoc, req }) => {
    // draft === true: only a new version is written, the main document stays as it is
  },
],

draft would be what updateDocument calls isSavingDraft. create and restoreVersion reach the same hooks and know the answer too.

Notes

• Seen on 3.88.0; the hook signature on main is unchanged.
• Related: [v4] Simplify Draft/Publish Workflow and Version States #15125, which makes the same point from the workflow side. Hooks that know which kind of write is happening would help there as well.