feat(nested): add trunk select strategy

closes #6759

Author: KaelWD

packages/api-generator/src/locale/en/nested.json

@@ -5,6 +5,6 @@
     "opened": "An array containing the values of currently opened groups. Can be two-way bound with `v-model:opened`.",
     "openStrategy": "Affects how items with children behave when expanded.\n- **multiple:** Any number of groups can be open at once.\n- **single:** Only one group at each level can be open, opening a group will cause others to close.\n- **list:** Multiple, but all other groups will close when an item is selected.",
     "selected": "An array containing the values of currently selected items. Can be two-way bound with `v-model:selected`.",
-    "selectStrategy": "Affects how items with children behave when selected.\n- **leaf:** Only leaf nodes (items without children) can be selected.\n- **independent:** All nodes can be selected whether they have children or not.\n- **classic:** Selecting a parent node will cause all children to be selected, parent nodes will be displayed as selected if all their descendants are selected. Only leaf nodes will be added to the model."
+    "selectStrategy": "Affects how items with children behave when selected.\n- **leaf:** Only leaf nodes (items without children) can be selected.\n- **independent:** All nodes can be selected whether they have children or not.\n- **classic:** Selecting a parent node will cause all children to be selected, parent nodes will be displayed as selected if all their descendants are selected. Only leaf nodes will be added to the model.\n- **trunk**: Same as classic but if all of a node's children are selected then only that node will be added to the model."
   }
 }

packages/vuetify/src/composables/nested/__tests__/selectStrategies.spec.ts

@@ -1,7 +1,14 @@
 /* eslint-disable max-len */
 /* eslint-disable sonarjs/no-identical-functions */
 // Utilities
-import { classicSelectStrategy, independentSelectStrategy, independentSingleSelectStrategy, leafSelectStrategy, leafSingleSelectStrategy } from '../selectStrategies'
+import {
+  classicSelectStrategy,
+  independentSelectStrategy,
+  independentSingleSelectStrategy,
+  leafSelectStrategy,
+  leafSingleSelectStrategy,
+  trunkSelectStrategy,
+} from '../selectStrategies'
 
 describe('selectStrategies', () => {
   describe('independent', () => {
@@ -732,4 +739,56 @@ describe('selectStrategies', () => {
       ]))
     })
   })
+
+  describe('trunk', () => {
+    it('selects individual leaves', () => {
+      const strategy = trunkSelectStrategy(false)
+
+      const value = new Map([
+        ['1', 'indeterminate'],
+        ['2', 'on'],
+        ['3', 'indeterminate'],
+        ['4', 'on'],
+      ] as const)
+
+      const children = new Map([
+        ['1', ['2', '3']],
+        ['3', ['4', '5']],
+      ])
+
+      const parents = new Map([
+        ['2', '1'],
+        ['3', '1'],
+        ['4', '3'],
+        ['5', '3'],
+      ])
+
+      expect(strategy.out(value, children, parents)).toEqual(['2', '4'])
+    })
+
+    it('selects a parent node', () => {
+      const strategy = trunkSelectStrategy(false)
+
+      const value = new Map([
+        ['1', 'indeterminate'],
+        ['3', 'on'],
+        ['4', 'on'],
+        ['5', 'on'],
+      ] as const)
+
+      const children = new Map([
+        ['1', ['2', '3']],
+        ['3', ['4', '5']],
+      ])
+
+      const parents = new Map([
+        ['2', '1'],
+        ['3', '1'],
+        ['4', '3'],
+        ['5', '3'],
+      ])
+
+      expect(strategy.out(value, children, parents)).toEqual(['3'])
+    })
+  })
 })

packages/vuetify/src/composables/nested/nested.ts

@@ -26,6 +26,7 @@ import {
   independentSingleSelectStrategy,
   leafSelectStrategy,
   leafSingleSelectStrategy,
+  trunkSelectStrategy,
 } from './selectStrategies'
 import { consoleError, getCurrentInstance, propsFactory } from '@/util'
 
@@ -49,6 +50,7 @@ export type SelectStrategyProp =
   | 'independent'
   | 'single-independent'
   | 'classic'
+  | 'trunk'
   | SelectStrategy
   | ((mandatory: boolean) => SelectStrategy)
 export type OpenStrategyProp = 'single' | 'multiple' | 'list' | OpenStrategy
@@ -154,6 +156,7 @@ export const useNested = (props: NestedProps) => {
       case 'leaf': return leafSelectStrategy(props.mandatory)
       case 'independent': return independentSelectStrategy(props.mandatory)
       case 'single-independent': return independentSingleSelectStrategy(props.mandatory)
+      case 'trunk': return trunkSelectStrategy(props.mandatory)
       case 'classic':
       default: return classicSelectStrategy(props.mandatory)
     }

packages/vuetify/src/composables/nested/selectStrategies.ts

@@ -209,3 +209,29 @@ export const classicSelectStrategy = (mandatory?: boolean): SelectStrategy => {
 
   return strategy
 }
+
+export const trunkSelectStrategy = (mandatory?: boolean): SelectStrategy => {
+  const parentStrategy = classicSelectStrategy(mandatory)
+
+  const strategy: SelectStrategy = {
+    select: parentStrategy.select,
+    in: parentStrategy.in,
+    out: (v, children, parents) => {
+      const arr = []
+
+      for (const [key, value] of v.entries()) {
+        if (value === 'on') {
+          if (parents.has(key)) {
+            const parent = parents.get(key)
+            if (v.get(parent) === 'on') continue
+          }
+          arr.push(key)
+        }
+      }
+
+      return arr
+    },
+  }
+
+  return strategy
+}