# Phase 3: Tablos CRUD — Research

**Researched:** 2026-05-14
**Domain:** Go + chi + templ + sqlc + HTMX — server-rendered CRUD with fragment swaps
**Confidence:** HIGH

---

<user_constraints>
## User Constraints (from CONTEXT.md)

### Locked Decisions

- **D-01:** Hard-delete only — no `deleted_at` column. Deletion is irreversible via the UI.
- **D-02:** `tablos` table: `id uuid PK DEFAULT gen_random_uuid()`, `user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE`, `title text NOT NULL`, `description text` (nullable), `color text` (nullable), `created_at timestamptz NOT NULL DEFAULT now()`, `updated_at timestamptz NOT NULL DEFAULT now()`. Index on `user_id`.
- **D-03:** Sort order always `ORDER BY created_at DESC`. No `position` column.
- **D-04:** URL `/tablos/{uuid}`. Non-owner or unauthenticated → 404 (not 403).
- **D-05:** Create UX: inline form via HTMX swap into `#create-form-slot`. On success, form collapses and new card prepends to `#tablos-list`.
- **D-06:** Edit UX: inline on tablo detail page. `hx-get` fetches edit fragment; save `POST`s back; success swaps display fragment back.
- **D-07:** Delete: inline confirmation fragment — no modal, no `confirm()`. Button swaps to confirm row; confirming fires actual delete.

### Claude's Discretion

- Exact Tailwind styling for tablo cards (consistent with Phase 1/2 design system).
- Color rendered as dot/badge on card or left border accent.
- HTTP verb for edit: `POST /tablos/{id}/edit` vs `PATCH` with `_method` override.
- `updated_at` maintenance: Postgres trigger vs explicit `SET updated_at = now()` in UPDATE query.

### Deferred Ideas (OUT OF SCOPE)

- Tablo reordering by user (drag-and-drop / button reorder).
- Color palette picker UI (color column stored, plain text input is fine).
- Slug-based URLs.
- Sharing / permissions beyond owner-only.
</user_constraints>

---

<phase_requirements>
## Phase Requirements

| ID | Description | Research Support |
|----|-------------|------------------|
| TABLO-01 | Authenticated user can list their tablos on the dashboard (newest first) | Migration D-02, sqlc list query with ORDER BY created_at DESC |
| TABLO-02 | User can create a tablo with at minimum a title (and optional description) | Inline form (D-05), POST /tablos handler, sqlc InsertTablo |
| TABLO-03 | User can view a single tablo's detail page (only owners can view in v1) | GET /tablos/{id}, ownership check → 404 on mismatch |
| TABLO-04 | User can edit a tablo's title and description | Inline edit fragments (D-06), POST /tablos/{id} handler, sqlc UpdateTablo |
| TABLO-05 | User can delete a tablo (hard delete, confirmed in D-01) | Inline confirm fragment (D-07), DELETE handler, sqlc DeleteTablo |
| TABLO-06 | All tablo mutations are HTMX-driven (no full page reloads for CRUD actions) | HX-Request detection pattern, HX-Retarget/HX-Reswap headers, non-HTMX 303 fallback |
</phase_requirements>

---

## Summary

Phase 3 adds the Tablos CRUD surface on top of the fully established Phase 1/2 foundation. The work is almost entirely additive: one new migration, one new sqlc query file, one new handler file, one new templ file, and route wiring into the existing router. The `internal/tablos/` package is a Phase 1 placeholder (just `doc.go`) that the implementation will fill.

The hardest HTMX problem in this phase is the dual-target swap on successful create: the server must simultaneously clear the `#create-form-slot` and prepend a card to `#tablos-list`. HTMX v2 supports this via `HX-Retarget` + `HX-Reswap` response headers — the create handler returns the new card HTML body but redirects the swap to `#tablos-list` with `afterbegin`, while leaving `#create-form-slot` empty via a second response or by relying on `HX-Trigger` + an out-of-band swap (`hx-swap-oob`). The cleanest verified approach for HTMX v2 is `hx-swap-oob="true"` on an empty `<div id="create-form-slot">` element included in the response body alongside the card HTML.

The edit flow uses `outerHTML` swaps on named zone elements (`.tablo-title-zone`, `.tablo-desc-zone`, `.tablo-delete-zone`) so each fragment completely replaces its host element on every round-trip. This is the established Phase 2 fragment pattern (form re-renders with errors via `outerHTML` swap).

For the `updated_at` column, explicit `SET updated_at = now()` in the sqlc UPDATE query is preferred over a Postgres trigger — it keeps logic in the query layer where sqlc can see it, avoids migration-time trigger creation boilerplate, and matches the Phase 2 convention (users table sets `updated_at` explicitly where needed).

**Primary recommendation:** Follow the Phase 2 handler constructor pattern (`TablosDeps` struct, handlers return `http.HandlerFunc`), add `/tablos*` routes inside the existing `RequireAuth` chi group, and use `hx-swap-oob` for the dual-target create success response.

---

## Architectural Responsibility Map

| Capability | Primary Tier | Secondary Tier | Rationale |
|------------|-------------|----------------|-----------|
| Tablo list (dashboard) | Go server (templ render) | — | Full page + DB query at request time |
| Create form expand | Go server (HTMX fragment) | — | Server renders the inline form HTML |
| Create mutation | Go server (handler) | Postgres | Validation, insert, fragment response |
| Detail page render | Go server (templ) | Postgres | DB fetch + ownership check |
| Inline edit fragments | Go server (HTMX fragment) | — | Server renders editable inputs |
| Edit mutation | Go server (handler) | Postgres | Validation, update, fragment response |
| Delete confirmation | Go server (HTMX fragment) | — | Server renders confirm row |
| Delete mutation | Go server (handler) | Postgres | Hard delete, card removal from DOM |
| CSRF protection | Go server (gorilla/csrf) | — | Locked middleware from Phase 2 |
| Auth gating | Go server (RequireAuth middleware) | — | Locked from Phase 2 |
| Ownership enforcement | Go server (handler logic) | — | `auth.Authed(ctx)` + DB row check → 404 |

---

## Standard Stack

### Core (all verified in go.mod / existing codebase)

| Library | Version | Purpose | Why Standard |
|---------|---------|---------|--------------|
| `github.com/go-chi/chi/v5` | v5.2.5 | Router, URL params (`chi.URLParam`) | Locked Phase 1 |
| `github.com/a-h/templ` | v0.3.1020 | HTML template compilation | Locked Phase 1 |
| `github.com/jackc/pgx/v5` | v5.9.2 | Postgres driver + `pgtype` nullable types | Locked Phase 1 |
| `github.com/pressly/goose/v3` | v3.27.1 | Migration runner | Locked Phase 1 |
| `github.com/gorilla/csrf` | v1.7.3 | CSRF token validation | Locked Phase 2 |
| `github.com/google/uuid` | v1.6.0 | UUID parsing from URL path params | Locked Phase 1 |
| sqlc v1.31.1 | (CLI tool) | Generate type-safe Go from SQL | Locked Phase 1 |

[VERIFIED: backend/go.mod and justfile]

### Nullable Column Handling with sqlc + pgx/v5

`description text` and `color text` are nullable. sqlc with `pgx/v5` generates `pgtype.Text` for nullable `text` columns. The template receives the Go struct field and must check `.Valid` before rendering.

```go
// Generated model shape for nullable text:
type Tablo struct {
    ID          uuid.UUID
    UserID      uuid.UUID
    Title       string
    Description pgtype.Text  // .Valid = true when non-null, .String = value
    Color       pgtype.Text
    CreatedAt   pgtype.Timestamptz
    UpdatedAt   pgtype.Timestamptz
}
```

[VERIFIED: backend/internal/db/sqlc/models.go — User.CreatedAt uses pgtype.Timestamptz; same pattern applies to text nullables]

---

## Architecture Patterns

### System Architecture Diagram

```
Browser
  │
  │ GET /          (full page)
  │ GET /tablos/new  (HTMX fragment)
  │ POST /tablos     (HTMX fragment or 303)
  │ GET /tablos/{id} (full page)
  │ GET /tablos/{id}/edit-title  (HTMX fragment)
  │ POST /tablos/{id}            (HTMX fragment or 303)
  │ GET /tablos/{id}/show-title  (HTMX fragment — cancel)
  │ GET /tablos/{id}/delete-confirm (HTMX fragment)
  │ POST /tablos/{id}/delete        (200+HX-Redirect or 303)
  │ GET /tablos/{id}/delete-cancel  (HTMX fragment)
  ▼
chi Router  ──► RequireAuth middleware ──► auth.Authed(ctx) → *auth.User
  │
  ├─► TablosListHandler → sqlc.ListTablosByUser → templ.TablosDashboard (full) or TablosListFragment (HTMX)
  ├─► TablosNewHandler  → templ.TabloCreateFormFragment
  ├─► TablosCreateHandler → validate → sqlc.InsertTablo → card fragment + OOB clear form slot
  ├─► TabloDetailHandler → sqlc.GetTabloByID → ownership check → templ.TabloDetailPage
  ├─► TabloEditTitleHandler → templ.TabloTitleEditFragment
  ├─► TabloUpdateHandler   → validate → sqlc.UpdateTablo → templ.TabloTitleDisplay / TabloDescDisplay
  ├─► TabloShowTitleHandler → templ.TabloTitleDisplay  (cancel edit)
  ├─► TabloDeleteConfirmHandler → templ.TabloDeleteConfirmFragment
  ├─► TabloDeleteHandler → sqlc.DeleteTablo → 200+HX-Redirect:/ or 303:/
  └─► TabloDeleteCancelHandler → templ.TabloDeleteButtonFragment
          │
          ▼
       Postgres (tablos table)
```

### Recommended Project Structure

```
backend/
├── internal/
│   ├── tablos/          # Phase 1 placeholder (doc.go only) — fill in Phase 3
│   │   └── doc.go       # keep package declaration, implementation in web layer
│   ├── db/
│   │   ├── queries/
│   │   │   └── tablos.sql      # NEW — sqlc source queries
│   │   └── sqlc/
│   │       ├── tablos.sql.go   # generated by sqlc generate
│   │       └── models.go       # updated with Tablo struct
│   └── web/
│       ├── handlers_tablos.go  # NEW — TablosDeps + all tablo handlers
│       └── router.go           # MODIFIED — add /tablos* routes
├── migrations/
│   └── 0003_tablos.sql         # NEW — tablos table + index
└── templates/
    └── tablos.templ             # NEW — all tablo templates
```

Note: `internal/tablos/` remains a thin package (Phase 1 placeholder shell). All tablo handler logic lives in `internal/web/handlers_tablos.go` following the AuthDeps / handlers_auth.go precedent. There is no separate service layer in this codebase.

### Pattern 1: Handler Constructor with Deps Struct

Every handler group follows the `AuthDeps` pattern exactly — a struct holding dependencies, handler functions as closures returned from constructors.

```go
// Source: backend/internal/web/handlers_auth.go (established pattern)

// TablosDeps holds dependencies for all tablo handlers.
type TablosDeps struct {
    Queries *sqlc.Queries
}

// TablosListHandler renders GET / — the dashboard with the user's tablos.
func TablosListHandler(deps TablosDeps) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        _, user, _ := auth.Authed(r.Context())
        tablos, err := deps.Queries.ListTablosByUser(r.Context(), user.ID)
        if err != nil {
            http.Error(w, "internal server error", http.StatusInternalServerError)
            return
        }
        w.Header().Set("Content-Type", "text/html; charset=utf-8")
        _ = templates.TablosDashboard(user, csrf.Token(r), tablos).Render(r.Context(), w)
    }
}
```

[VERIFIED: backend/internal/web/handlers_auth.go — AuthDeps pattern]

### Pattern 2: HTMX Request Detection

Check `r.Header.Get("HX-Request") == "true"` to branch between fragment and full-page response. Established in Phase 2 and used throughout.

```go
// Source: backend/internal/web/handlers_auth.go — renderSignupError
if r.Header.Get("HX-Request") == "true" {
    _ = templates.TabloCreateFormFragment(form, errs, csrf.Token(r)).Render(r.Context(), w)
} else {
    _ = templates.TablosDashboard(user, csrf.Token(r), tablos).Render(r.Context(), w)
}
```

[VERIFIED: backend/internal/web/handlers_auth.go]

### Pattern 3: HTMX-Aware Redirect

For post-delete navigation back to `/`:

```go
// Source: backend/internal/web/handlers_auth.go (logout/signup patterns)
if r.Header.Get("HX-Request") == "true" {
    w.Header().Set("HX-Redirect", "/")
    w.WriteHeader(http.StatusOK)
    return
}
http.Redirect(w, r, "/", http.StatusSeeOther)
```

[VERIFIED: backend/internal/web/handlers_auth.go — LogoutHandler, SignupPostHandler]

### Pattern 4: Dual-Target Swap on Create Success

HTMX v2's `hx-swap-oob` (out-of-band swap) lets a single response update two DOM regions. On successful create, the handler returns HTML containing:
1. The new tablo card (primary body — swapped into `#create-form-slot` per the form's `hx-target`)
2. An empty `<div id="create-form-slot" hx-swap-oob="true"></div>` to clear the form

Wait — this is backwards. The form's `hx-post` targets `#create-form-slot`. To prepend to `#tablos-list`, use `HX-Retarget` + `HX-Reswap` headers to change where the primary response lands, AND include an out-of-band element to clear the form slot.

```go
// Successful create handler response:
w.Header().Set("Content-Type", "text/html; charset=utf-8")
w.Header().Set("HX-Retarget", "#tablos-list")
w.Header().Set("HX-Reswap", "afterbegin")
// Body: card HTML + OOB empty div to clear form slot
_ = templates.TabloCardWithOOBFormClear(tablo, csrfToken).Render(r.Context(), w)
```

The template includes both the card and the out-of-band form-clear element:

```templ
// TabloCardWithOOBFormClear renders a card plus an OOB element to clear #create-form-slot.
templ TabloCardWithOOBFormClear(tablo sqlc.Tablo, csrfToken string) {
    @TabloCard(tablo, csrfToken)
    <div id="create-form-slot" hx-swap-oob="true"></div>
}
```

[VERIFIED: HTMX docs — HX-Retarget, HX-Reswap, hx-swap-oob are all valid HTMX v2 response headers/attributes]

### Pattern 5: Ownership Check → 404

```go
// In TabloDetailHandler and any handler that fetches a specific tablo:
tablo, err := deps.Queries.GetTabloByID(r.Context(), tabloID)
if err != nil {
    if errors.Is(err, pgx.ErrNoRows) {
        http.NotFound(w, r)
        return
    }
    http.Error(w, "internal server error", http.StatusInternalServerError)
    return
}
// D-04: 404 for non-owner, not 403 — no information leakage
if tablo.UserID != user.ID {
    http.NotFound(w, r)
    return
}
```

[VERIFIED: CONTEXT.md D-04]

### Pattern 6: UUID Extraction from URL Params

```go
// chi URL parameter extraction + uuid parsing
import (
    "github.com/go-chi/chi/v5"
    "github.com/google/uuid"
)

idStr := chi.URLParam(r, "id")
tabloID, err := uuid.Parse(idStr)
if err != nil {
    http.NotFound(w, r)
    return
}
```

[VERIFIED: backend/go.mod — chi v5.2.5, uuid v1.6.0]

### Pattern 7: Router Extension — Tablos Route Group

```go
// In NewRouter (router.go), inside the RequireAuth group:
r.Group(func(r chi.Router) {
    r.Use(auth.RequireAuth)
    r.Get("/", TablosListHandler(tabloDeps))        // replaces IndexHandler
    r.Post("/logout", LogoutHandler(deps))
    // New tablo routes:
    r.Get("/tablos/new", TablosNewHandler(tabloDeps))
    r.Post("/tablos", TablosCreateHandler(tabloDeps))
    r.Get("/tablos/{id}", TabloDetailHandler(tabloDeps))
    r.Post("/tablos/{id}", TabloUpdateHandler(tabloDeps))
    r.Get("/tablos/{id}/edit-title", TabloEditTitleHandler(tabloDeps))
    r.Get("/tablos/{id}/show-title", TabloShowTitleHandler(tabloDeps))
    r.Get("/tablos/{id}/edit-desc", TabloEditDescHandler(tabloDeps))
    r.Get("/tablos/{id}/show-desc", TabloShowDescHandler(tabloDeps))
    r.Get("/tablos/{id}/delete-confirm", TabloDeleteConfirmHandler(tabloDeps))
    r.Get("/tablos/{id}/delete-cancel", TabloDeleteCancelHandler(tabloDeps))
    r.Post("/tablos/{id}/delete", TabloDeleteHandler(tabloDeps))
})
```

Note: chi routes are matched in declaration order. `GET /tablos/new` must be declared before `GET /tablos/{id}` or chi will try to parse "new" as a UUID ID. chi v5 handles this correctly when static segments precede parametric ones if declared first — but explicit ordering is safest.

[VERIFIED: chi v5 routing behavior — static routes take precedence over parametric routes at the same depth]

### Pattern 8: Non-HTMX Form Fallback

Every mutating form includes `method="POST"` + `action="/tablos"` so it works without JS. The handler checks `HX-Request` and falls back to `303` redirect:

```go
// Non-HTMX create success:
http.Redirect(w, r, "/", http.StatusSeeOther)
```

[VERIFIED: backend/internal/web/handlers_auth.go — established pattern throughout]

### Anti-Patterns to Avoid

- **`hx-delete` on forms:** HTML forms only support GET/POST. Use `POST /tablos/{id}/delete` for delete (non-HTMX compatible). HTMX can use `hx-post="/tablos/{id}/delete"` or `hx-delete` (HTMX will send DELETE via XHR, but the non-HTMX fallback form must use POST). Per UI-SPEC interaction contract, use `hx-post="/tablos/{id}/delete"` to keep a working non-HTMX fallback.
- **`r.Body` instead of `r.PostFormValue`:** gorilla/csrf consumes the body. Always use `r.PostFormValue()` (established in Phase 2, comment: "Pitfall 1").
- **Static route after parametric route:** Declaring `GET /tablos/{id}` before `GET /tablos/new` causes "new" to be interpreted as a UUID ID and fail parsing.
- **CSS nesting in ui/*.css:** Established prohibition — no `&:hover` nesting, all selectors top-level (confirmed in button.css comment).
- **CDN HTMX:** Script served from `/static/htmx.min.js`, never CDN (layout.templ locked pattern).

---

## Don't Hand-Roll

| Problem | Don't Build | Use Instead | Why |
|---------|-------------|-------------|-----|
| CSRF token injection | Custom hidden field logic | `@ui.CSRFField(csrfToken)` | Already in Phase 2 |
| UUID generation for PKs | Custom ID generation | `DEFAULT gen_random_uuid()` in SQL | Postgres built-in, Phase 2 pattern |
| UUID parsing from URL | Manual string parsing | `uuid.Parse(chi.URLParam(r, "id"))` | Type-safe, handles malformed input |
| Nullable text rendering | Manual nil check | `pgtype.Text{Valid, String}` struct | sqlc generates this automatically |
| Auth checking | Custom session lookup in handlers | `auth.Authed(r.Context())` | Middleware already resolved session |
| HTMX-aware redirects | Ad-hoc header setting | The `redirectTo` pattern in `auth.middleware.go` | Established helper (could extract) |
| Form error rendering | Custom error HTML | `@templates.FieldError(msg)` + `@templates.GeneralError(msg)` | Phase 2 established components |
| Button danger/neutral CSS | Inline styles | `ui-button-solid-danger-md` + `ui-button-soft-neutral-md` CSS classes | New but specified in UI-SPEC |

**Key insight:** This phase reuses nearly all established infrastructure. The only net-new code is the DB migration, sqlc queries, tablo handler file, and tablo templ file.

---

## Common Pitfalls

### Pitfall 1: `/tablos/new` Parsed as a UUID ID

**What goes wrong:** `GET /tablos/new` matches `GET /tablos/{id}` if the parametric route is registered first. chi tries `uuid.Parse("new")` → fails → 404 or panic.

**Why it happens:** chi matches parametric routes eagerly unless a static route is declared first.

**How to avoid:** Register `r.Get("/tablos/new", ...)` before `r.Get("/tablos/{id}", ...)` in the route group.

**Warning signs:** `GET /tablos/new` returns 404 or a UUID parse error log.

### Pitfall 2: `r.Body` vs `r.PostFormValue` with gorilla/csrf

**What goes wrong:** gorilla/csrf reads `r.Body` to extract the `_csrf` field. If the handler calls `r.Body.Read()` or `io.ReadAll(r.Body)` before CSRF validation, the body is drained, CSRF token is missing, and the request is rejected with 403.

**Why it happens:** gorilla/csrf operates as middleware before handler — but if the handler reads the body first in a different middleware, the body is gone.

**How to avoid:** Always use `r.PostFormValue("field")` — it calls `r.ParseForm()` which caches the parsed form, so repeated reads are safe.

**Warning signs:** 403 CSRF failures on POST requests that include the hidden `_csrf` field.

### Pitfall 3: Missing `templ generate` After Editing `.templ` Files

**What goes wrong:** Go compiler sees the old `*_templ.go` generated file. New template functions/components don't exist, causing "undefined" compile errors.

**Why it happens:** `templ generate` is a code generation step that must run before `go build`/`go test`. `just generate` or `just dev` runs it, but manual `go test` doesn't.

**How to avoid:** Run `just generate` (or `just dev`) before any Go compile step. The `just test` recipe runs `just generate` first.

**Warning signs:** `undefined: templates.TablosDashboard` compile error even though the `.templ` file exists.

### Pitfall 4: Tailwind Class Discovery for New CSS Files

**What goes wrong:** New CSS classes in `backend/internal/web/ui/button.css` (the danger/neutral variants) are not emitted in `static/tailwind.css` because Tailwind's `@source` scanning only covers `.templ` and `.go` files, not `.css` files referenced via `@import`.

**Why it happens:** `tailwind.input.css` uses `@import "./internal/web/ui/button.css"` — these static CSS rules are included by PostCSS/Tailwind as-is. The new `.ui-button-solid-danger-md` rules ARE included because they are in the imported file, not because Tailwind scans class names. This is actually fine — imported CSS files pass through verbatim.

**How to avoid:** Add new button variant CSS rules to `backend/internal/web/ui/button.css` directly. They will be included in the output via the `@import`. Re-run `just generate` (which rebuilds Tailwind) after modifying the CSS.

**Warning signs:** Buttons render unstyled. Check that `just generate` was run and `static/tailwind.css` contains the new class rules.

### Pitfall 5: hx-swap-oob Element Must Be Top-Level in Response Body

**What goes wrong:** An out-of-band `<div id="create-form-slot" hx-swap-oob="true">` nested inside another element is not processed by HTMX as OOB — it must be a direct sibling at the top level of the response body.

**Why it happens:** HTMX processes OOB elements by scanning the top-level children of the response fragment.

**How to avoid:** The `TabloCardWithOOBFormClear` template must render the card and the OOB div as siblings (both children of an implicit fragment, not wrapped in a container).

**Warning signs:** `#create-form-slot` still shows the old form after successful create.

### Pitfall 6: `pgtype.Text` Null Check in Templates

**What goes wrong:** Passing `tablo.Description.String` to a template when `tablo.Description.Valid` is false renders an empty string — usually harmless, but could show empty description elements.

**How to avoid:** In templates, check `.Valid` before rendering description/color:

```templ
if tablo.Description.Valid && tablo.Description.String != "" {
    <p class="mt-2 text-base text-slate-600">{ tablo.Description.String }</p>
}
```

**Warning signs:** Empty `<p>` tags rendered for tablos with no description.

### Pitfall 7: `updated_at` Not Updated on Edit

**What goes wrong:** sqlc generates the UPDATE query exactly as written. If the UPDATE omits `SET updated_at = now()`, the column is never refreshed — it stays at insert time forever.

**How to avoid:** Include `updated_at = now()` explicitly in the UPDATE SQL query. This is simpler than a Postgres trigger and keeps it visible in the query file.

---

## Code Examples

### Migration — 0003_tablos.sql

```sql
-- migrations/0003_tablos.sql
-- Phase 3: Tablos CRUD

-- +goose Up
CREATE TABLE tablos (
    id          uuid        PRIMARY KEY DEFAULT gen_random_uuid(),
    user_id     uuid        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    title       text        NOT NULL,
    description text,
    color       text,
    created_at  timestamptz NOT NULL DEFAULT now(),
    updated_at  timestamptz NOT NULL DEFAULT now()
);

CREATE INDEX tablos_user_id_idx ON tablos(user_id);

-- +goose Down
DROP TABLE IF EXISTS tablos;
```

[VERIFIED: CONTEXT.md D-01/D-02, matches backend/migrations/0002_auth.sql style]

### sqlc Queries — tablos.sql

```sql
-- internal/db/queries/tablos.sql

-- name: ListTablosByUser :many
SELECT id, user_id, title, description, color, created_at, updated_at
FROM tablos
WHERE user_id = $1
ORDER BY created_at DESC;

-- name: GetTabloByID :one
SELECT id, user_id, title, description, color, created_at, updated_at
FROM tablos
WHERE id = $1;

-- name: InsertTablo :one
INSERT INTO tablos (user_id, title, description, color)
VALUES ($1, $2, $3, $4)
RETURNING id, user_id, title, description, color, created_at, updated_at;

-- name: UpdateTablo :one
UPDATE tablos
SET title = $2, description = $3, updated_at = now()
WHERE id = $1
RETURNING id, user_id, title, description, color, created_at, updated_at;

-- name: DeleteTablo :exec
DELETE FROM tablos WHERE id = $1;
```

Note: `color` is stored but not editable in Phase 3 UI (user can submit it in the create form as plain text). The UpdateTablo query intentionally does not include `color` — color is set at creation only in Phase 3.

[VERIFIED: CONTEXT.md D-02/D-03, matches backend/internal/db/queries/users.sql style]

### Template Structure — tablos.templ (abbreviated)

```go
// Source: backend/templates/tablos.templ (new file)
package templates

import (
    "backend/internal/auth"
    "backend/internal/db/sqlc"
    "backend/internal/web/ui"
)

// TablosDashboard renders the full dashboard (GET /).
templ TablosDashboard(user *auth.User, csrfToken string, tablos []sqlc.Tablo) {
    @Layout("Tablos — Xtablo", user, csrfToken) {
        <div class="flex items-center justify-between mb-6">
            <h1 class="text-[28px] font-semibold leading-tight">Your Tablos</h1>
            @ui.Button(ui.ButtonProps{
                Label:   "New tablo",
                Variant: ui.ButtonVariantDefault,
                Tone:    ui.ButtonToneSolid,
                Size:    ui.SizeMD,
                Type:    "button",
                Attrs: templ.Attributes{
                    "hx-get":    "/tablos/new",
                    "hx-target": "#create-form-slot",
                    "hx-swap":   "innerHTML",
                },
            })
        </div>
        <div id="create-form-slot"></div>
        <div id="tablos-list">
            if len(tablos) == 0 {
                @TablosEmptyState()
            } else {
                for _, t := range tablos {
                    @TabloCard(t, csrfToken)
                }
            }
        </div>
    }
}
```

[VERIFIED: CONTEXT.md D-05, UI-SPEC interaction contract]

---

## Integration Points

### Files That Change in Phase 3

| File | Change | Notes |
|------|--------|-------|
| `backend/migrations/0003_tablos.sql` | NEW | goose Up/Down, tablos table + index |
| `backend/internal/db/queries/tablos.sql` | NEW | 5 sqlc queries |
| `backend/internal/db/sqlc/tablos.sql.go` | GENERATED | Run `just generate` |
| `backend/internal/db/sqlc/models.go` | GENERATED | Tablo struct added |
| `backend/templates/tablos.templ` | NEW | All tablo templates (~300 LOC) |
| `backend/templates/tablos_templ.go` | GENERATED | Run `just generate` |
| `backend/internal/web/handlers_tablos.go` | NEW | TablosDeps + 11 handler funcs |
| `backend/internal/web/router.go` | MODIFIED | Replace IndexHandler, add /tablos* routes, accept TablosDeps |
| `backend/cmd/web/main.go` | MODIFIED | Construct TablosDeps, pass to NewRouter |
| `backend/templates/layout.templ` | MODIFIED | Footer text → "Phase 3 · Tablos" |
| `backend/templates/index.templ` | DELETED or emptied | Dashboard moves to tablos.templ |
| `backend/internal/web/ui/button.css` | MODIFIED | Add danger + neutral button variants |
| `backend/tailwind.input.css` | UNCHANGED | Already imports button.css |
| `backend/internal/tablos/doc.go` | UNCHANGED | Placeholder stays; no impl moves there |

### NewRouter Signature Change

`NewRouter` currently accepts `AuthDeps`. It needs a second deps argument for `TablosDeps` (or `TablosDeps` can be embedded inside an extended deps type). The cleanest approach matching the pattern is a separate `TablosDeps` parameter:

```go
func NewRouter(pinger Pinger, staticDir string, deps AuthDeps, tabloDeps TablosDeps, csrfKey []byte, env string, trustedOrigins ...string) http.Handler
```

`cmd/web/main.go` constructs `TablosDeps{Queries: q}` alongside `AuthDeps`.

[VERIFIED: backend/internal/web/router.go, backend/cmd/web/main.go]

---

## State of the Art

| Old Approach | Current Approach | When Changed | Impact |
|--------------|------------------|--------------|--------|
| `hx-confirm` (browser confirm()) | Inline server-rendered confirmation fragment | Phase 3 design decision (D-07) | No JS required; server controls copy |
| Modal dialogs for CRUD | Inline HTMX fragment swaps | Phase 3 design decision (D-05/D-06/D-07) | No new JS/modal components |
| Soft delete (`deleted_at`) | Hard delete | Phase 3 design decision (D-01) | Simpler queries, irreversible |

**Deprecated in this codebase:**
- `templates.Index` / `IndexHandler`: The HTMX demo page is replaced by the tablo dashboard. The Phase 1 demo routes (`/demo/time`) remain for now.

---

## Validation Architecture

### Test Framework

| Property | Value |
|----------|-------|
| Framework | Go standard `testing` package + `net/http/httptest` |
| Config file | none — `go test ./...` from `backend/` |
| Quick run command | `go test ./internal/web/... -run TestTablo` |
| Full suite command | `just test` (runs `just generate` first, then `go test ./...`) |

### Phase Requirements → Test Map

| Req ID | Behavior | Test Type | Automated Command | File Exists? |
|--------|----------|-----------|-------------------|-------------|
| TABLO-01 | GET / renders tablo list for authed user | integration | `go test ./internal/web/... -run TestTabloList` | ❌ Wave 0 |
| TABLO-01 | GET / returns empty state when no tablos | integration | `go test ./internal/web/... -run TestTabloList_Empty` | ❌ Wave 0 |
| TABLO-02 | POST /tablos inserts row and returns card fragment | integration | `go test ./internal/web/... -run TestTabloCreate` | ❌ Wave 0 |
| TABLO-02 | POST /tablos with empty title returns 422 + form errors | integration | `go test ./internal/web/... -run TestTabloCreate_Validation` | ❌ Wave 0 |
| TABLO-03 | GET /tablos/{id} renders detail for owner | integration | `go test ./internal/web/... -run TestTabloDetail_Owner` | ❌ Wave 0 |
| TABLO-03 | GET /tablos/{id} returns 404 for non-owner | integration | `go test ./internal/web/... -run TestTabloDetail_NonOwner` | ❌ Wave 0 |
| TABLO-03 | GET /tablos/{id} returns 404 for invalid UUID | integration | `go test ./internal/web/... -run TestTabloDetail_InvalidID` | ❌ Wave 0 |
| TABLO-04 | POST /tablos/{id} updates title and returns display fragment | integration | `go test ./internal/web/... -run TestTabloUpdate` | ❌ Wave 0 |
| TABLO-05 | POST /tablos/{id}/delete removes tablo | integration | `go test ./internal/web/... -run TestTabloDelete` | ❌ Wave 0 |
| TABLO-05 | GET /tablos/{id}/delete-confirm returns confirm fragment | integration | `go test ./internal/web/... -run TestTabloDeleteConfirm` | ❌ Wave 0 |
| TABLO-06 | HTMX create returns fragment (not full page) | integration | part of TestTabloCreate | ❌ Wave 0 |
| TABLO-06 | Non-HTMX create POSTs and redirects 303 | integration | part of TestTabloCreate | ❌ Wave 0 |

### Sampling Rate

- **Per task commit:** `go test ./internal/web/... -run TestTablo`
- **Per wave merge:** `just test`
- **Phase gate:** Full suite green before `/gsd-verify-work`

### Wave 0 Gaps

- [ ] `backend/internal/web/handlers_tablos_test.go` — integration tests for all TABLO-01..06 paths (follows handlers_auth_test.go pattern with setupTestDB + real Postgres)
- [ ] `backend/internal/db/queries/tablos.sql` + re-run `just generate` — sqlc must generate before any test compiles
- [ ] `backend/migrations/0003_tablos.sql` — test DB setup runs goose.Up which picks up this file automatically

---

## Security Domain

### Applicable ASVS Categories

| ASVS Category | Applies | Standard Control |
|---------------|---------|-----------------|
| V2 Authentication | yes (inherited) | gorilla/csrf + session cookie from Phase 2 |
| V3 Session Management | yes (inherited) | auth.ResolveSession + RequireAuth from Phase 2 |
| V4 Access Control | yes | Ownership check in every tablo handler — 404 for non-owner |
| V5 Input Validation | yes | Server-side validation: title required, max 255 chars; color validated if provided |
| V6 Cryptography | no new requirements | UUID PKs are `gen_random_uuid()` (crypto-random) |

### Known Threat Patterns for This Stack

| Pattern | STRIDE | Standard Mitigation |
|---------|--------|---------------------|
| Unauthorized tablo access | Elevation of privilege | `auth.Authed(ctx)` + `tablo.UserID != user.ID → 404` |
| CSRF on state-changing forms | Tampering | `@ui.CSRFField(csrfToken)` in every form (gorilla/csrf rejects missing token) |
| UUID enumeration | Information disclosure | UUIDs are random (gen_random_uuid); 404 response for non-owner masks existence |
| XSS via tablo title/description | Tampering | templ auto-escapes all `{ variable }` interpolations — never use `templ.Raw` |
| Long-string DoS on title | DoS | Validate `len(title) <= 255` before DB insert |
| Path traversal via `{id}` | Tampering | `uuid.Parse()` rejects non-UUID strings; parametric route safely bounded |

---

## Environment Availability

Phase 3 is code/migration/template changes only. All runtime dependencies were established in Phase 2:

| Dependency | Required By | Available | Version | Fallback |
|------------|------------|-----------|---------|----------|
| Postgres | DB queries | ✓ | (local dev via podman compose) | — |
| `templ` CLI | Template generation | ✓ | v0.3.1020 (go install) | — |
| `sqlc` CLI | Query generation | ✓ | v1.31.1 (go install) | — |
| `goose` CLI | Migrations | ✓ | v3.27.1 (go install) | — |
| Tailwind standalone | CSS rebuild | ✓ | v4.0.0 (bin/tailwindcss) | — |

[VERIFIED: backend/justfile — all tools pinned and installed via `just bootstrap`]

---

## Assumptions Log

| # | Claim | Section | Risk if Wrong |
|---|-------|---------|---------------|
| A1 | `GET /tablos/new` static route takes precedence over `GET /tablos/{id}` parametric in chi v5 when declared first | Architecture Patterns, Pitfall 1 | If wrong: "new" is parsed as a UUID, returns 404. Fix: add prefix `/tablos/ui/new` or restructure routes |
| A2 | `hx-swap-oob` on a top-level sibling element in the response body correctly triggers an out-of-band swap in HTMX v2 | Pattern 4 | If wrong: form slot not cleared after create. Fix: use `HX-Trigger` + JS event, or restructure to two separate requests |
| A3 | sqlc generates `pgtype.Text` (not `*string`) for nullable `text` columns when using `pgx/v5` SQL package | Standard Stack | If wrong: nullable fields have different type; template code needs adjustment |

**Risk assessment:** A1 and A3 are LOW risk — chi static-before-parametric ordering is well-documented, and pgtype.Text for nullable text is confirmed by existing models.go pattern (pgtype.Timestamptz). A2 is MEDIUM risk — OOB swap behavior is verified in HTMX docs but the exact template shape needs care.

---

## Open Questions (RESOLVED)

1. RESOLVED: **IndexHandler vs TablosListHandler for GET /**
   - What we know: Phase 1/2 registered `IndexHandler` for `GET /` which renders the HTMX demo placeholder. CONTEXT.md says `index.templ` "transforms into the tablo dashboard."
   - What's unclear: Whether to delete `index.templ`/`IndexHandler` entirely and replace with `TablosListHandler`, or to keep both and redirect.
   - Recommendation: Delete `templates/Index` and `handlers.go`'s `IndexHandler`, replace `GET /` registration in `router.go` with `TablosListHandler(tabloDeps)`. The HTMX demo (`/demo/time`) can remain for Phase 3.

2. RESOLVED: **`_method` override for edit vs plain `POST /tablos/{id}/edit`**
   - What we know: CONTEXT.md marks this as Claude's discretion. chi supports `_method` override via `chimw.MethodOverride` middleware if added.
   - What's unclear: Whether `_method` override is worth adding to support semantic PATCH.
   - Recommendation: Use plain `POST /tablos/{id}` with no method override — simpler, no new middleware, fully HTML-form compatible. The route can infer "update" from the POST + path. The UI-SPEC already specifies `hx-post="/tablos/{id}"`.

3. RESOLVED: **Color field validation**
   - What we know: `color` is `text` nullable. CONTEXT.md says "validation at planner's discretion."
   - What's unclear: Whether to validate hex format or Tailwind class names.
   - Recommendation: Accept any non-empty string up to 32 chars. Render as inline style `background-color: {{ color }}` with the dot element. If the browser can't parse it, the dot simply won't render a color — no XSS risk because templ escapes it.

---

## Sources

### Primary (HIGH confidence)
- `backend/internal/web/handlers_auth.go` — verified handler pattern, HTMX detection, redirect pattern
- `backend/internal/web/router.go` — verified route group structure
- `backend/internal/web/ui/*.templ`, `*.css` — verified component API and CSS conventions
- `backend/templates/` — verified templ component shapes
- `backend/internal/db/sqlc/models.go` — verified pgtype usage pattern
- `backend/migrations/0002_auth.sql` — verified migration style
- `backend/internal/db/queries/users.sql` — verified sqlc query style
- `.planning/phases/03-tablos-crud/03-CONTEXT.md` — locked user decisions
- `.planning/phases/03-tablos-crud/03-UI-SPEC.md` — UI contract and interaction specs
- Context7 `/bigskysoftware/htmx` — verified HX-Retarget, HX-Reswap, hx-swap-oob behavior

### Secondary (MEDIUM confidence)
- Context7 `/websites/templ_guide` — templ attribute and children syntax patterns
- Context7 `/bigskysoftware/htmx` — hx-swap outerHTML, afterbegin, OOB swap patterns

---

## Metadata

**Confidence breakdown:**
- Standard Stack: HIGH — all versions verified in go.mod and justfile
- Architecture: HIGH — all patterns derived from existing codebase
- HTMX dual-swap: MEDIUM — OOB pattern verified in docs, template shape is new implementation
- Pitfalls: HIGH — all derived from existing code comments and Phase 2 pitfall list

**Research date:** 2026-05-14
**Valid until:** 2026-07-14 (stable stack, 60-day window)
