## API

### Tree props

| Property | Description | Type | Default |
| -------- | ----------- | ---- | ------- |
| allowClear | Whether allow clear | boolean | false |
| defaultValue | To set the initial selected treeNode(s). | string\|string\[] | - |
| disabled | Disabled or not | boolean | false |
| dropdownClassName | className of dropdown menu | string | - |
| dropdownMatchSelectWidth | Determine whether the dropdown menu and the select input are the same width | boolean | true |
| dropdownStyle | To set the style of the dropdown menu | object | - |
| filterTreeNode | Whether to filter treeNodes by input value. The value of `treeNodeFilterProp` is used for filtering by default. | boolean\|Function(inputValue: string, treeNode: TreeNode) (should return boolean) | Function |
| getPopupContainer | To set the container of the dropdown menu. The default is to create a `div` element in `body`, you can reset it to the scrolling area and make a relative reposition. | Function(triggerNode) | () => document.body |
| labelInValue | whether to embed label in value, turn the format of value from `string` to `{value: string, label: VNode, halfChecked: string[]}` | boolean | false |
| loadData | Load data asynchronously. | function(node) | - |
| multiple | Support multiple or not, will be `true` when enable `treeCheckable`. | boolean | false |
| placeholder | Placeholder of the select input | string\|slot | - |
| searchPlaceholder | Placeholder of the search input | string\|slot | - |
| showCheckedStrategy | The way show selected item in box. **Default:** just show child nodes. **`TreeSelect.SHOW_ALL`:** show all checked treeNodes (include parent treeNode). **`TreeSelect.SHOW_PARENT`:** show checked treeNodes (just show parent treeNode). | enum { TreeSelect.SHOW_ALL, TreeSelect.SHOW_PARENT, TreeSelect.SHOW_CHILD } | TreeSelect.SHOW_CHILD |
| showSearch | Whether to display a search input in the dropdown menu(valid only in the single mode) | boolean | false |
| size | To set the size of the select input, options: `large` `small` | string | 'default' |
| suffixIcon | The custom suffix icon | VNode \| slot | - |
| treeCheckable | Whether to show checkbox on the treeNodes | boolean | false |
| treeCheckStrictly | Whether to check nodes precisely (in the `checkable` mode), means parent and child nodes are not associated, and it will make `labelInValue` be true | boolean | false |
| treeData | Data of the treeNodes, manual construction work is no longer needed if this property has been set(ensure the Uniqueness of each value) | array<{ value, label, children, [disabled, disableCheckbox, selectable] }> | \[] |
| treeDataSimpleMode | Enable simple mode of treeData.(treeData should like this: [{id:1, pId:0, value:'1', label:"test1",...},...], pId is parent node's id) | false\|Array<{ id: string, pId: string, rootPId: null }> | false |
| treeDefaultExpandAll | Whether to expand all treeNodes by default | boolean | false |
| treeDefaultExpandedKeys | Default expanded treeNodes | string\[] \| number\[] | - |
| treeExpandedKeys | Set expanded keys | string\[] \| number\[] | - |
| treeNodeFilterProp | Will be used for filtering if `filterTreeNode` returns true | string | 'value' |
| treeNodeLabelProp | Will render as content of select | string | 'title' |
| value(v-model) | To set the current selected treeNode(s). | string\|string\[] | - |

### Events
| Events Name | Description | Arguments |
| --- | --- | --- |
| change | A callback function, can be executed when selected treeNodes or input value change | function(value, label, extra) |
| search | A callback function, can be executed when the search input changes. | function(value: string) |
| select | A callback function, can be executed when you select a treeNode. | function(value, node, extra) |
| treeExpand | A callback function, can be executed when treeNode expanded | function(expandedKeys) |

### Tree Methods

| Name | Description |
| ---- | ----------- |
| blur() | remove focus |
| focus() | get focus |

### TreeNode props

> We recommend you to use `treeData` rather than `TreeNode`, to avoid the trouble of manual construction.

| Property | Description | Type | Default |
| -------- | ----------- | ---- | ------- |
| selectable | can be selected | boolean | true |
| disableCheckbox | Disables the checkbox of the treeNode | boolean | false |
| disabled | Disabled or not | boolean | false |
| isLeaf | Leaf node or not | boolean | false |
| key | Required property, should be unique in the tree | string \| number | - |
| title | Content showed on the treeNodes | string\|slot | '---' |
| value | Will be treated as `treeNodeFilterProp` by default, should be unique in the tree | string | - |
| scopedSlots | When using treeNodes, you can use this property to configure the properties that support the slot, such as `scopedSlots: { title: 'XXX'}` | object | - |