Frontend: preview distribution #56

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opened 2026-06-26 00:04:31 +02:00 by myrmidex · 0 comments

myrmidex commented

2026-06-26 00:04:31 +02:00

Owner

Context

Split from #34. A user enters an income amount and sees how it would distribute across their buckets — without persisting. Uses the existing stateless preview endpoint.

Scope

Income-amount input on the scenario show page.
Submit → POST /api/scenarios/{scenario}/projections/preview (application/ld+json, body {amount}) → render the ProjectionPreviewOutput (per-bucket allocations + totals).
Drive the DigitalProgressBar visuals from the preview result (show projected fill per bucket).
Owner-scoped: previewing a scenario you don't own returns 404 (#50 Story 4) — handled by the not-found state from #53.

Notes

The endpoint is STATELESS — nothing is saved; it's a pure projection (see PLATFORM.md "Allocation Preview" + the #32 engine).
This is the showcase flow for the allocation engine (#32) — the phased fill order, overflow handling, etc. become visible here.

Depends on

#33 (scaffold), #53 (scenario show page with buckets to project onto)

Out of scope

Persisting an allocation / actually distributing income (the preview is read-only by design; a persist flow would be a separate future ticket once a "commit allocation" backend op exists).

Testing

Per SPA test setup; preview render from a mocked result + the 404 path.

## Context Split from #34. A user enters an income amount and sees how it would distribute across their buckets — without persisting. Uses the existing stateless preview endpoint. ## Scope - Income-amount input on the scenario show page. - Submit → `POST /api/scenarios/{scenario}/projections/preview` (`application/ld+json`, body `{amount}`) → render the `ProjectionPreviewOutput` (per-bucket allocations + totals). - Drive the DigitalProgressBar visuals from the preview result (show projected fill per bucket). - Owner-scoped: previewing a scenario you don't own returns 404 (#50 Story 4) — handled by the not-found state from #53. ## Notes - The endpoint is STATELESS — nothing is saved; it's a pure projection (see PLATFORM.md "Allocation Preview" + the #32 engine). - This is the showcase flow for the allocation engine (#32) — the phased fill order, overflow handling, etc. become visible here. ## Depends on - #33 (scaffold), #53 (scenario show page with buckets to project onto) ## Out of scope - Persisting an allocation / actually distributing income (the preview is read-only by design; a persist flow would be a separate future ticket once a "commit allocation" backend op exists). ## Testing - Per SPA test setup; preview render from a mocked result + the 404 path.