Informational hint on the confirmation page when the same email has
already submitted the form. Not a block — the submission proceeds
normally. Privacy-safe: only shown to the submitter themselves.
Scope: same form_schema_id only. Cross-form/cross-event detection
would leak info about other forms.
- New FormSubmissionDuplicateDetector service queries by
form_submissions.public_submitter_email (trim + case-insensitive)
scoped to the schema, status=submitted, excluding the current
submission. Errors are swallowed + logged so a detector failure
never blocks the submit response.
- PublicFormSubmissionController enriches the submit response by
setting a transient duplicate_submission_data attribute on the
submission before resource serialisation.
- PublicFormSubmissionResource serialises a duplicate_submission
block with count, first_submitted_at, plus backend-authored
Dutch title + body (plural-agreement + IntlDateFormatter for
"23 april 2026"-style long-form dates). Null when no priors,
no email, or detector error.
- DuplicateSubmissionHint.vue (warning-typed tonal VAlert) above
IdentityMatchBanner on FormConfirmation. Prefers backend copy
with Intl-based Dutch date fallback for safety.
- 16 new backend assertions across the detector and the full
submit-response flow; 5 new Vitest assertions for the hint.
Note on scope: spec suggested extracting email from values via
schema binding; the codebase's public flow captures submitter
email in a guaranteed column (public_submitter_email) populated
by the stepper's Contactgegevens step. Using that directly is
both simpler and more correct for the duplicate-by-submitter
semantic. When FORM-05's binding-based extractor lands, this
detector can migrate without changing its public API.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bert.hausmans
b6a3a17b0a