refactor(Tree): Implements expanding the folding child element

packages/element3/src/components/Tree/src/TreeMain.vue

@@ -33,17 +33,25 @@ export default {
     checked: { type: Array as PropType<ID[]>, default: () => [] },
     showCheckbox: Boolean,
     checkOnClickNode: Boolean,
-    checkStrictly: Boolean
+    checkStrictly: Boolean,
+
+    iconClass: { type: String, default: 'el-icon-caret-right' },
+    renderAfterExpand: { type: Boolean, default: true },
+    accordion: Boolean,
+    autoExpandParent: { type: Boolean, default: true },
+    expandOnClickNode: { type: Boolean, default: true },
+    expanded: { type: Array as PropType<ID[]>, default: () => [] },
+    defaultExpandAll: Boolean
   },
-  emits: ['update:modelValue', 'update:checked'],
+  emits: ['update:modelValue', 'update:checked', 'update:expanded'],
   setup(props, ctx) {
     const elTree = getCurrentInstance().proxy
     provide('elTree', elTree)
     const tree = new Tree(props.modelValue, props.defaultNodeKey)
     ctx.emit('update:modelValue', tree.rawNodesProxy)
     const rootChildren = computed(() => tree.root.children)
-
     tree.rootProxy.setStrictly(props.checkStrictly)
+
     watchEffect(
       () => {
         tree.setCheckedByIds(props.checked)
@@ -57,6 +65,22 @@ export default {
       ctx.emit('update:checked', tree.getCheckedIds())
     })
 
+    if (props.defaultExpandAll) {
+      tree.expandAll()
+    }
+    watchEffect(
+      () => {
+        tree.expandNodeByIds(props.expanded)
+      },
+      {
+        flush: 'post'
+        // exec after wait component flush
+      }
+    )
+    watchEffect(() => {
+      ctx.emit('update:expanded', tree.getExpandedNodeIds())
+    })
+
     return {
       tree,
       rootChildren

packages/element3/src/components/Tree/src/TreeNode.vue

@@ -3,26 +3,37 @@
     class="el-tree-node"
     :class="{
       'is-checked': node.isChecked,
-      'is-focusable': !node.isDisabled
+      'is-focusable': !node.isDisabled,
+      'is-expanded': node.isExpanded
     }"
     role="TreeNode"
     :aria-checked="node.isChecked"
     :aria-disabled="node.isDisabled"
     tabindex="-1"
     :id="'TreeNode' + node.id"
     :data-node-id="node.id"
+    @click.stop="onClickTreeNode"
   >
     <div
       class="el-tree-node__content"
       :style="{ 'padding-left': node.level * elTree.indent + 'px' }"
       @click="onClickTreeNodeContent"
     >
+      <span
+        :class="[
+          { expanded: node.isExpanded, 'is-leaf': node.isLeaf },
+          'el-tree-node__expand-icon',
+          elTree.iconClass
+        ]"
+        @click.stop="onClickTreeNodeExpand"
+      >
+      </span>
       <el-checkbox
         v-if="elTree.showCheckbox"
         :modelValue="node.isChecked"
         :indeterminate="node.isIndeterminate"
         :disabled="node.isDisabled"
-        @click.prevent="onClickCheckbox"
+        @click.prevent.stop="onClickCheckbox"
       >
       </el-checkbox>
       <span
@@ -35,7 +46,13 @@
       ></el-node-content>
     </div>
     <el-collapse-transition>
-      <div class="el-tree-node__children" role="group">
+      <div
+        v-show="node.isExpanded"
+        v-if="!elTree.renderAfterExpand || node.isRendered"
+        class="el-tree-node__children"
+        role="group"
+        :aria-expanded="node.isExpanded"
+      >
         <el-tree-node
           v-for="child in node.children"
           :key="child.id"
@@ -67,7 +84,13 @@ export default {
   },
 
   setup(props) {
-    const elTree = inject('elTree', { indent: 10, checkOnClickNode: false })
+    const elTree = inject('elTree', {
+      indent: 10,
+      checkOnClickNode: false,
+      accordion: false,
+      autoExpandParent: true,
+      expandOnClickNode: true
+    })
     const onClickTreeNodeContent = () => {
       if (!elTree.checkOnClickNode) {
         return
@@ -80,10 +103,21 @@ export default {
       }
       props.node.setChecked()
     }
+    const onClickTreeNodeExpand = () => {
+      if (elTree.accordion) props.node.collapse()
+      else props.node.expand(undefined, elTree.autoExpandParent)
+    }
+    const onClickTreeNode = () => {
+      if (elTree.expandOnClickNode) {
+        onClickTreeNodeExpand()
+      }
+    }
     return {
       elTree,
       onClickCheckbox,
-      onClickTreeNodeContent
+      onClickTreeNodeContent,
+      onClickTreeNode,
+      onClickTreeNodeExpand
     }
   }
 }

packages/element3/src/components/Tree/src/entity/Tree.ts

@@ -69,4 +69,29 @@ export class Tree<RawNode extends RawNodeBase> {
 
     return ids
   }
+
+  expandNodeByIds(ids: ID[]): void {
+    this.rootProxy.depthEach((currentNode: TreeNode) => {
+      if (ids.includes(currentNode.id)) {
+        currentNode.expand(true)
+      }
+    })
+  }
+
+  getExpandedNodeIds(): ID[] {
+    const ids = []
+    this.rootProxy.depthEach((currentNode: TreeNode) => {
+      if (currentNode !== this.rootProxy && currentNode.isExpanded) {
+        ids.push(currentNode.id)
+      }
+    })
+
+    return ids
+  }
+
+  expandAll(v = true): void {
+    this.root.depthEach((currentNode) => {
+      currentNode.expand(v, false)
+    })
+  }
 }

packages/element3/src/components/Tree/src/entity/TreeNode.ts

@@ -25,10 +25,20 @@ export class TreeNode implements TreeNodePublicProp {
   label: string
   parent: TreeNode
   children: TreeNode[] = []
-  private _isLeaf = false
-  private _isChecked = false
-  private _isStrictly = false
-  private _isDisabled = false
+  private _isLeaf: boolean
+  private _isChecked: boolean
+  private _isStrictly: boolean
+  private _isDisabled: boolean
+  private _isExpanded: boolean
+  private _isRendered = false
+
+  get isRendered(): boolean {
+    return this._isRendered
+  }
+
+  get isExpanded(): boolean {
+    return this._isExpanded
+  }
 
   get isDisabled(): boolean {
     return this._isDisabled
@@ -88,14 +98,17 @@ export class TreeNode implements TreeNodePublicProp {
       isLeaf = false,
       isChecked = false,
       isStrictly = false,
-      isDisabled = false
+      isDisabled = false,
+      isExpanded = false
     } = {}
   ) {
     this.id = id ?? idSeed++
     this.label = label
     this._isLeaf = isLeaf
     this._isStrictly = isStrictly
     this._isDisabled = isDisabled
+    this._isExpanded = isExpanded
+
     this.setChecked(isChecked)
 
     this.appendChild(...children)
@@ -206,4 +219,26 @@ export class TreeNode implements TreeNodePublicProp {
     dfs(this, 1)
     isFunction(downToUpCallBack) && downToUpCallBack(this, this.parent, 0)
   }
+
+  expand(v = !this._isExpanded, isAutoExpandParent = false): void {
+    if (this.isLeaf) {
+      return
+    }
+    this._isExpanded = v
+    if (v) {
+      this._isRendered = true
+    }
+    if (isAutoExpandParent) {
+      this.parent?.expand(true, true)
+    }
+  }
+
+  collapse(v = !this._isExpanded): void {
+    const parent = this.parent
+    if (!parent) {
+      return
+    }
+    parent.children.forEach((node) => node.expand(false))
+    this.expand(v)
+  }
 }

packages/element3/src/components/Tree/tests/TreeMain.spec.ts

@@ -23,7 +23,8 @@ describe('TreeMain.vue', () => {
     ]
     const wrapper = mount(TreeMain, {
       props: {
-        modelValue: rawNodes
+        modelValue: rawNodes,
+        renderAfterExpand: false
       }
     })
 
@@ -36,7 +37,8 @@ describe('TreeMain.vue', () => {
     const rawNodes = []
     const wrapper = mount(TreeMain, {
       props: {
-        modelValue: rawNodes
+        modelValue: rawNodes,
+        renderAfterExpand: false
       }
     })
 
@@ -45,7 +47,7 @@ describe('TreeMain.vue', () => {
   it('reactive tree data', async () => {
     const wrapper = mount({
       template: `
-        <el-Tree-main v-model="nodes"></el-Tree-main>
+        <el-Tree-main v-model="nodes" :renderAfterExpand="false"></el-Tree-main>
       `,
       components: { elTreeMain: TreeMain },
       setup() {
@@ -90,7 +92,7 @@ describe('TreeMain.vue', () => {
   it('reactive tree data(OptionsAPI)', async () => {
     const wrapper = mount({
       template: `
-        <el-Tree-main v-model="nodes"></el-Tree-main>
+        <el-Tree-main v-model="nodes" :renderAfterExpand="false"></el-Tree-main>
       `,
       components: { elTreeMain: TreeMain },
       data() {
@@ -129,7 +131,7 @@ describe('TreeMain.vue', () => {
   it('Realize node multi - selection function', async () => {
     const wrapper = mount({
       template: `
-        <el-Tree-main v-model="nodes" v-model:checked="checked" show-checkbox></el-Tree-main>
+        <el-Tree-main v-model="nodes" v-model:checked="checked" show-checkbox :renderAfterExpand="false"></el-Tree-main>
       `,
       components: { elTreeMain: TreeMain },
       setup() {
@@ -173,7 +175,7 @@ describe('TreeMain.vue', () => {
   it('Based on the check-on-click-node implementation, whether the node is selected when the node is clicked', async () => {
     const wrapper = mount({
       template: `
-        <el-tree-main v-model="nodes" v-model:checked="checked" show-checkbox check-on-click-node></el-tree-main>
+        <el-tree-main v-model="nodes" v-model:checked="checked" show-checkbox check-on-click-node :renderAfterExpand="false"></el-tree-main>
       `,
       components: { elTreeMain: TreeMain },
       setup() {
@@ -206,7 +208,7 @@ describe('TreeMain.vue', () => {
   it('Implement, in the case of displaying checkboxes, whether to strictly follow the parent-child discordant practice', async () => {
     const wrapper = mount({
       template: `
-        <el-tree-main v-model="nodes" v-model:checked="checked" show-checkbox check-strictly></el-tree-main>
+        <el-tree-main v-model="nodes" v-model:checked="checked" show-checkbox check-strictly :renderAfterExpand="false"></el-tree-main>
       `,
       components: { elTreeMain: TreeMain },
       setup() {
@@ -237,4 +239,67 @@ describe('TreeMain.vue', () => {
     await node2.trigger('click')
     expect(wrapper.vm.checked).toEqual([2])
   })
+
+  it('expand a node', async () => {
+    const rawNodes = [
+      {
+        id: 1,
+        label: 'Node1',
+        children: [
+          {
+            id: 11,
+            label: 'Node1-1'
+          }
+        ]
+      }
+    ]
+    const wrapper = mount(TreeMain, {
+      props: {
+        modelValue: rawNodes,
+        renderAfterExpand: false
+      }
+    })
+    await wrapper.find('#TreeNode1').trigger('click')
+    expect(wrapper.find('#TreeNode1').classes()).toContain('is-expanded')
+  })
+
+  it('expand a node and vModel expanded', async () => {
+    const rawNodes = [
+      {
+        id: 1,
+        label: 'Node1',
+        children: [
+          {
+            id: 11,
+            label: 'Node1-1'
+          }
+        ]
+      },
+      {
+        id: 2,
+        label: 'Node2',
+        children: [
+          {
+            id: 21,
+            label: 'Node2-1'
+          }
+        ]
+      }
+    ]
+    const expanded = ref([1])
+    const wrapper = mount(TreeMain, {
+      props: {
+        modelValue: rawNodes,
+        renderAfterExpand: false,
+        expanded: expanded,
+        'onUpdate:expanded'(v) {
+          expanded.value = v
+        }
+      }
+    })
+    await nextTick()
+    await wrapper.find('#TreeNode2').trigger('click')
+    expect(wrapper.find('#TreeNode1').classes()).toContain('is-expanded')
+    expect(expanded.value).toEqual([1, 2])
+  })
 })