Adds the shared optimistic-concurrency contract so a stale second tab can no longer
silently overwrite a fresher edit. PR1 lands the infra + the Block reference aggregate;
PRs 2–4 fan the same recipe across the other 8 roots (design: #253#issuecomment-8472).
Contract
- `IVersionedAggregate` (`int Version`) on all 9 replace-all roots (ProgramSchedule,
Block, Template, DecoTemplate, Playlist, Collection, Playout, MultiCollection,
RerunCollection), EF-mapped `.IsConcurrencyToken()`; one dual-provider migration
`AddAggregateVersions` (nullable:false, default 0).
- Strong `ETag` of `Version` on the aggregate GET; `If-Match` on the PUT; mismatch →
412 (distinct from the §3a 409 build-lock guard). Successful PUT returns the new ETag.
- `PreconditionFailedError : BaseError` → 412 in `ApiResults.ToErrorResult`;
`ConcurrencyHeaders.ParseIfMatch/SetETag`; malformed If-Match → 400; `*`/absent =
Phase-1 force-write.
Block reference wiring
- Handler: standalone `Either` via `CheckVersion` AFTER validation (never through
`Apply`, which Join()-flattens the subtype to 422), unconditional `Version++`,
`SaveChangesWithConcurrencyGuard` backstop (DbUpdateConcurrencyException → 412).
- `BlockViewModel.Version` (header-only, not echoed in the body); controller sets the
ETag on GET items and on the successful PUT.
- SPA: `client.requestWithMeta` seam; `blocks.getBlockItemsWithMeta` + `replaceBlock`
If-Match/ETag round-trip; `BlockEditor` holds the ETag, sends If-Match, and on 412
opens a blocking "changed elsewhere — reload" dialog.
Tests
- Handler contract tests: stale-If-Match → 412 (no mutation), matching/absent → success
+ bump, no-op save still bumps, and a two-context racing save → 412; proven
non-vacuous (drop `.IsConcurrencyToken()` → the race test fails).
- Controller tests: malformed If-Match → 400, If-Match threaded to the command, ETag on
GET/PUT, 412 passthrough. SPA: requestWithMeta ETag, replaceBlock If-Match, 412 dialog.
Docs: api-conventions §7a, spa-conventions §4a, domain-model glossary, decisions log.
Refs #253
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* refactor classic and block schedules to use same alternate schedule selector
* handle start year and end year
* add migrations for classic and block schedules
* allow editing block template start and end year
* add tests that include years
* add date range editing to classic (alternate) schedules
* fix running tests locally
* restore media files load; needed for local folder scanners
* update changelog
* feedback
* add deco groups and decos; set default deco for block playout
* use block playout default deco for watermark
* add deco templates, groups and deco template editor
* associate deco template with playout template
* use deco template item watermark for playback
* update changelog for decos
* schedule blocks in order
* block minutes must be multiple of 15
* improve block minutes entry, validation and display
* confirm deleting blocks and block groups
* confirm deleting templates and template groups
* skip unchanged blocks in playout
timothyandClaude Opus 4.8