refactor(createDataTable): drop items option for registry pattern

.claude/rules/composables.md

@@ -26,6 +26,7 @@ Scope-specific mechanics for `packages/0/src/composables/**`. Covers naming, fac
 - §6.6 `useProxyModel`
 - §6.7 `useProxyRegistry`
 - §6.8 Register / unregister lifecycle contract
+- §6.10 Collection composables: no `items` option
 - §7 Events & lifecycle
 - §9 Errors & invariants
 
@@ -343,6 +344,10 @@ const table = createDataTable({
 - The composable has exactly one correct implementation, and consumers have no reason to swap it. Example: `useHotkey` — the listener semantics are fixed.
 - You want to switch behavior based on a boolean flag. Use an option (`mode: 'client' | 'server'`) rather than dressing it up as an adapter. Adapters are for swapping *implementations*, not for flipping a known toggle.
 
+### Collection composables: no `items` option
+
+A composable that owns a collection of values exposes `register` / `onboard` / `unregister`. It never accepts an `items` option in its factory — row identity, order, and per-row state live in the registry. Followed by `createRegistry`, `createModel`, `createSelection`, `createSingle`, `createGroup`, `createStep`, `createNested`, `createSortable`, `createKanban`, `createQueue`, `createTimeline`, `createTokens`, and (after the recent refactor) `createDataTable`. Full rule and migration shape: PHILOSOPHY §6.10.
+
 ### `useProxyModel` and `useProxyRegistry` — cross-link
 
 Both composables are covered in PHILOSOPHY §6.6 and §6.7. Repeating the when-to-use summary here for composable authors:
@@ -494,3 +499,4 @@ Pure transformers (`toRef`, `toElement`, `toValue`) are fine to call inline —
 - [ ] No DOM event binding inside the composable
 - [ ] ID generation through `useId()`
 - [ ] Trinity return only from `createTrinity` / `createContext` / `createPlugin`
+- [ ] Composable that owns a collection of values uses `register` / `onboard`, never an `items` option (PHILOSOPHY §6.10)

.claude/rules/new-feature-checklist.md

@@ -189,3 +189,4 @@ Prefer extending an existing pattern over creating a new one.
 - [ ] Feature appears in `apps/docs/build/generated/api-whitelist.ts` after build
 - [ ] `<DocsApi />` renders on the new docs page
 - [ ] Maturity level matches the promotion criteria table (don't self-promote to `stable` or `mature` — those require a maintainer)
+- [ ] Collection composable surface uses `register` / `onboard` (no `items` option) — see PHILOSOPHY §6.10

apps/docs/src/examples/composables/create-data-table/basic/BasicTable.vue

@@ -4,13 +4,14 @@
   import { users } from './data'
 
   const table = createDataTable({
-    items: users,
-    columns,
     pagination: { itemsPerPage: 5 },
   })
 
-  function sortIcon (key: string) {
-    const dir = table.sort.direction(key)
+  table.columns.onboard(columns)
+  table.onboard(users.map(value => ({ id: value.id, value })))
+
+  function arrow (id: string) {
+    const dir = table.sort.direction(id)
     if (dir === 'asc') return '↑'
     if (dir === 'desc') return '↓'
     return ''
@@ -32,13 +33,13 @@
         <thead>
           <tr class="border-b border-divider bg-surface-tint">
             <th
-              v-for="col in columns"
-              :key="col.key"
+              v-for="col in table.columns.values()"
+              :key="col.id"
               class="px-4 py-3 text-left font-medium cursor-pointer select-none hover:text-primary transition-colors"
-              @click="table.sort.toggle(col.key)"
+              @click="table.sort.toggle(col.id)"
             >
               {{ col.title }}
-              <span class="ml-1 text-xs opacity-50">{{ sortIcon(col.key) }}</span>
+              <span class="ml-1 text-xs opacity-50">{{ arrow(col.id) }}</span>
             </th>
           </tr>
         </thead>

apps/docs/src/examples/composables/create-data-table/basic/columns.ts

@@ -1,8 +1,8 @@
-import type { DataTableColumn } from '@vuetify/v0'
+import type { DataTableColumnTicketInput } from '@vuetify/v0'
 import type { User } from './data'
 
-export const columns: DataTableColumn<User>[] = [
-  { key: 'name', title: 'Name', sortable: true, filterable: true },
-  { key: 'email', title: 'Email', sortable: true, filterable: true },
-  { key: 'role', title: 'Role', sortable: true },
+export const columns: DataTableColumnTicketInput<User>[] = [
+  { id: 'name', title: 'Name', sortable: true, filterable: true },
+  { id: 'email', title: 'Email', sortable: true, filterable: true },
+  { id: 'role', title: 'Role', sortable: true },
 ]

apps/docs/src/examples/composables/create-data-table/features/FeaturesTable.vue

@@ -4,8 +4,6 @@
   import { employees } from './data'
 
   const table = createDataTable({
-    items: employees,
-    columns,
     groupBy: 'department',
     openAll: true,
     mandate: true,
@@ -15,14 +13,17 @@
     pagination: { itemsPerPage: 20 },
   })
 
-  function sortIcon (key: string) {
-    const dir = table.sort.direction(key)
+  table.columns.onboard(columns)
+  table.onboard(employees.map(value => ({ id: value.id, value })))
+
+  function arrow (id: string) {
+    const dir = table.sort.direction(id)
     if (dir === 'asc') return '↑'
     if (dir === 'desc') return '↓'
     return ''
   }
 
-  function formatSalary (value: number) {
+  function format (value: number) {
     return `$${value.toLocaleString()}`
   }
 </script>
@@ -68,13 +69,13 @@
             </th>
 
             <th
-              v-for="col in columns"
-              :key="col.key"
+              v-for="col in table.columns.values()"
+              :key="col.id"
               class="px-4 py-3 text-left font-medium cursor-pointer select-none hover:text-primary transition-colors"
-              @click="table.sort.toggle(col.key)"
+              @click="table.sort.toggle(col.id)"
             >
               {{ col.title }}
-              <span class="ml-1 text-xs opacity-50">{{ sortIcon(col.key) }}</span>
+              <span class="ml-1 text-xs opacity-50">{{ arrow(col.id) }}</span>
             </th>
           </tr>
         </thead>
@@ -85,7 +86,7 @@
               class="bg-surface-tint cursor-pointer hover:bg-surface-variant transition-colors"
               @click="table.grouping.toggle(group.key)"
             >
-              <td class="px-4 py-2 font-medium" :colspan="columns.length + 1">
+              <td class="px-4 py-2 font-medium" :colspan="table.columns.size + 1">
                 <span class="mr-2 text-xs">{{ table.grouping.isOpen(group.key) ? '−' : '+' }}</span>
                 {{ group.key }}
                 <span class="ml-2 text-xs opacity-50">({{ group.items.length }})</span>
@@ -111,7 +112,7 @@
 
                 <td class="px-4 py-3">{{ item.name }}</td>
                 <td class="px-4 py-3">{{ item.department }}</td>
-                <td class="px-4 py-3 font-mono">{{ formatSalary(item.salary) }}</td>
+                <td class="px-4 py-3 font-mono">{{ format(item.salary) }}</td>
 
                 <td class="px-4 py-3">
                   <span

apps/docs/src/examples/composables/create-data-table/features/columns.ts

@@ -1,11 +1,11 @@
-import type { DataTableColumn } from '@vuetify/v0'
+import type { DataTableColumnTicketInput } from '@vuetify/v0'
 import type { Employee } from './data'
 
-export const columns: DataTableColumn<Employee>[] = [
-  { key: 'name', title: 'Name', sortable: true, filterable: true },
-  { key: 'department', title: 'Department', sortable: true },
+export const columns: DataTableColumnTicketInput<Employee>[] = [
+  { id: 'name', title: 'Name', sortable: true, filterable: true },
+  { id: 'department', title: 'Department', sortable: true },
   {
-    key: 'salary',
+    id: 'salary',
     title: 'Salary',
     sortable: true,
     filterable: true,
@@ -17,5 +17,5 @@ export const columns: DataTableColumn<Employee>[] = [
       return String(value).includes(query)
     },
   },
-  { key: 'active', title: 'Status', sortable: true },
+  { id: 'active', title: 'Status', sortable: true },
 ]

apps/docs/src/examples/composables/create-data-table/server/ServerTable.vue

@@ -1,48 +1,43 @@
 <script setup lang="ts">
   import { createDataTable, ServerDataTableAdapter } from '@vuetify/v0'
   import { shallowRef, watch } from 'vue'
-  import { fetchUsers } from './api'
+  import { fetchPage } from './api'
   import { columns } from './columns'
 
-  import type { User } from './api'
-
-  const serverItems = shallowRef<User[]>([])
-  const totalCount = shallowRef(0)
-  const isLoading = shallowRef(false)
+  const total = shallowRef(0)
+  const loading = shallowRef(false)
 
   const table = createDataTable({
-    items: serverItems,
-    columns,
     pagination: { itemsPerPage: 5 },
-    adapter: new ServerDataTableAdapter({
-      total: totalCount,
-      loading: isLoading,
-    }),
+    adapter: new ServerDataTableAdapter({ total, loading }),
   })
 
-  async function loadData () {
-    isLoading.value = true
+  table.columns.onboard(columns)
+
+  async function load () {
+    loading.value = true
 
-    const result = await fetchUsers(
+    const result = await fetchPage(
       table.query.value,
       table.sort.columns.value,
       table.pagination.page.value,
       table.pagination.itemsPerPage,
     )
 
-    totalCount.value = result.total
-    serverItems.value = result.items
-    isLoading.value = false
+    total.value = result.total
+    table.clear()
+    table.onboard(result.items.map(value => ({ id: value.id, value })))
+    loading.value = false
   }
 
   watch(
     [table.query, table.sort.columns, table.pagination.page],
-    () => loadData(),
+    () => load(),
     { immediate: true },
   )
 
-  function sortIcon (key: string) {
-    const dir = table.sort.direction(key)
+  function arrow (id: string) {
+    const dir = table.sort.direction(id)
     if (dir === 'asc') return '↑'
     if (dir === 'desc') return '↓'
     return ''
@@ -76,13 +71,13 @@
         <thead>
           <tr class="border-b border-divider bg-surface-tint">
             <th
-              v-for="col in columns"
-              :key="col.key"
+              v-for="col in table.columns.values()"
+              :key="col.id"
               class="px-4 py-3 text-left font-medium cursor-pointer select-none hover:text-primary transition-colors"
-              @click="table.sort.toggle(col.key)"
+              @click="table.sort.toggle(col.id)"
             >
               {{ col.title }}
-              <span class="ml-1 text-xs opacity-50">{{ sortIcon(col.key) }}</span>
+              <span class="ml-1 text-xs opacity-50">{{ arrow(col.id) }}</span>
             </th>
           </tr>
         </thead>
@@ -109,7 +104,7 @@
 
     <div class="flex items-center justify-between text-sm">
       <span class="opacity-60">
-        {{ totalCount }} total
+        {{ total }} total
       </span>
 
       <div class="flex gap-1">

apps/docs/src/examples/composables/create-data-table/server/api.ts

@@ -23,7 +23,7 @@ export interface FetchResult {
  * Simulates a server API call with filtering, sorting, and pagination.
  * Returns only the current page of results after a short delay.
  */
-export function fetchUsers (
+export function fetchPage (
   query: string,
   sorts: SortEntry[],
   page: number,
@@ -46,9 +46,9 @@ export function fetchUsers (
       if (sorts.length > 0) {
         const { key, direction } = sorts[0]
         result.sort((a, b) => {
-          const aVal = String(a[key as keyof User])
-          const bVal = String(b[key as keyof User])
-          const cmp = aVal.localeCompare(bVal)
+          const left = String(a[key as keyof User])
+          const right = String(b[key as keyof User])
+          const cmp = left.localeCompare(right)
           return direction === 'desc' ? -cmp : cmp
         })
       }

apps/docs/src/examples/composables/create-data-table/server/columns.ts

@@ -1,8 +1,8 @@
-import type { DataTableColumn } from '@vuetify/v0'
+import type { DataTableColumnTicketInput } from '@vuetify/v0'
 import type { User } from './api'
 
-export const columns: DataTableColumn<User>[] = [
-  { key: 'name', title: 'Name', sortable: true, filterable: true },
-  { key: 'email', title: 'Email', sortable: true, filterable: true },
-  { key: 'department', title: 'Department', sortable: true },
+export const columns: DataTableColumnTicketInput<User>[] = [
+  { id: 'name', title: 'Name', sortable: true, filterable: true },
+  { id: 'email', title: 'Email', sortable: true, filterable: true },
+  { id: 'department', title: 'Department', sortable: true },
 ]

apps/docs/src/examples/composables/create-data-table/virtual/VirtualTable.vue

@@ -2,20 +2,21 @@
   import { createDataTable, VirtualDataTableAdapter, createVirtual } from '@vuetify/v0'
   import { computed } from 'vue'
   import { columns } from './columns'
-  import { generateUsers } from './data'
+  import { generate } from './data'
 
-  const items = generateUsers(1000)
+  const items = generate(1000)
 
   const table = createDataTable({
-    items,
-    columns,
     adapter: new VirtualDataTableAdapter(),
   })
 
+  table.columns.onboard(columns)
+  table.onboard(items.map(value => ({ id: value.id, value })))
+
   const virtual = createVirtual(table.items, { itemHeight: 40 })
   const {
     element,
-    items: virtualItems,
+    items: visible,
     offset,
     size,
     scroll,
@@ -24,11 +25,11 @@
   const stats = computed(() => ({
     total: items.length,
     filtered: table.items.value.length,
-    rendered: virtualItems.value.length,
+    rendered: visible.value.length,
   }))
 
-  function sortIcon (key: string) {
-    const dir = table.sort.direction(key)
+  function arrow (id: string) {
+    const dir = table.sort.direction(id)
     if (dir === 'asc') return '↑'
     if (dir === 'desc') return '↓'
     return ''
@@ -61,13 +62,13 @@
           <thead class="sticky top-0 z-10 bg-surface">
             <tr class="border-b border-divider bg-surface-tint">
               <th
-                v-for="col in columns"
-                :key="col.key"
+                v-for="col in table.columns.values()"
+                :key="col.id"
                 class="px-4 py-3 text-left font-medium cursor-pointer select-none hover:text-primary transition-colors"
-                @click="table.sort.toggle(col.key)"
+                @click="table.sort.toggle(col.id)"
               >
                 {{ col.title }}
-                <span class="ml-1 text-xs opacity-50">{{ sortIcon(col.key) }}</span>
+                <span class="ml-1 text-xs opacity-50">{{ arrow(col.id) }}</span>
               </th>
             </tr>
           </thead>
@@ -76,7 +77,7 @@
             <tr :style="{ height: `${offset}px` }" />
 
             <tr
-              v-for="item in virtualItems"
+              v-for="item in visible"
               :key="item.raw.id"
               class="h-[40px] hover:bg-surface-tint transition-colors"
             >

apps/docs/src/examples/composables/create-data-table/virtual/columns.ts

@@ -1,8 +1,8 @@
-import type { DataTableColumn } from '@vuetify/v0'
+import type { DataTableColumnTicketInput } from '@vuetify/v0'
 import type { User } from './data'
 
-export const columns: DataTableColumn<User>[] = [
-  { key: 'name', title: 'Name', sortable: true, filterable: true },
-  { key: 'email', title: 'Email', sortable: true, filterable: true },
-  { key: 'score', title: 'Score', sortable: true, sort: (a: unknown, b: unknown) => Number(a) - Number(b) },
+export const columns: DataTableColumnTicketInput<User>[] = [
+  { id: 'name', title: 'Name', sortable: true, filterable: true },
+  { id: 'email', title: 'Email', sortable: true, filterable: true },
+  { id: 'score', title: 'Score', sortable: true, sort: (a: unknown, b: unknown) => Number(a) - Number(b) },
 ]

apps/docs/src/examples/composables/create-data-table/virtual/data.ts

@@ -5,7 +5,7 @@ export interface User {
   score: number
 }
 
-export function generateUsers (count = 1000): User[] {
+export function generate (count = 1000): User[] {
   return Array.from({ length: count }, (_, i) => ({
     id: i + 1,
     name: `User ${i + 1}`,