--- category: Components type: Data Display title: Tree cover: https://gw.alipayobjects.com/zos/alicdn/Xh-oWqg9k/Tree.svg --- A hierarchical list structure component. ## When To Use Almost anything can be represented in a tree structure. Examples include directories, organization hierarchies, biological classifications, countries, etc. The `Tree` component is a way of representing the hierarchical relationship between these things. You can also expand, collapse, and select a treeNode within a `Tree`. ## API ### Tree props | Property | Description | Type | Default | Version | | --- | --- | --- | --- | --- | | treeData | treeNode of tree, please use `treeNodes` before v1.1.4 | [TreeNode[]](#TreeNode) | - | | | fieldNames | Replace the title,key and children fields in treeNode with the corresponding fields in treeData | object | { children:'children', title:'title', key:'key' } | 3.0.0 | | autoExpandParent | Whether to automatically expand a parent treeNode | boolean | true | | | blockNode | Whether treeNode fill remaining horizontal space | boolean | false | | | checkable | Adds a `Checkbox` before the treeNodes | boolean | false | | | checkedKeys(v-model) | (Controlled) Specifies the keys of the checked treeNodes (PS: When this specifies the key of a treeNode which is also a parent treeNode, all the children treeNodes of will be checked; and vice versa, when it specifies the key of a treeNode which is a child treeNode, its parent treeNode will also be checked. When `checkable` and `checkStrictly` is true, its object has `checked` and `halfChecked` property. Regardless of whether the child or parent treeNode is checked, they won't impact each other. | string\[] \| number\[] \| {checked: string\[] \| number\[], halfChecked: string\[] \| number\[]} | \[] | | | checkStrictly | Check treeNode precisely; parent treeNode and children treeNodes are not associated | boolean | false | | | defaultExpandAll | Whether to expand all treeNodes by default | boolean | false | | | disabled | whether disabled the tree | bool | false | | | draggable | Specifies whether this Tree is draggable (IE > 8) | boolean | false | | | expandedKeys(v-model) | (Controlled) Specifies the keys of the expanded treeNodes | string\[] \| number\[] | \[] | | | filterTreeNode | Defines a function to filter (highlight) treeNodes. When the function returns `true`, the corresponding treeNode will be highlighted | function(node) | - | | | loadData | Load data asynchronously | function(node) | - | | | loadedKeys | (Controlled) Set loaded tree nodes. Need work with `loadData` | string\[] \| number\[] | \[] | | | multiple | Allows selecting multiple treeNodes | boolean | false | | | selectable | whether can be selected | boolean | true | | | selectedKeys(v-model) | (Controlled) Specifies the keys of the selected treeNodes | string\[] \| number\[] | - | | | showIcon | Shows the icon before a TreeNode's title. There is no default style; you must set a custom style for it if set to `true` | boolean | false | | | switcherIcon | customize collapse/expand icon of tree node | slot | - | | | showLine | Shows a connecting line | boolean \| {showLeafIcon: boolean}(3.0+) | false | | | title | custom title | slot | | 2.0.0 | ### Events | Events Name | Description | Arguments | | --- | --- | --- | | check | Callback function for when the onCheck event occurs | function(checkedKeys, e:{checked: bool, checkedNodes, node, event}) | | dragend | Callback function for when the onDragEnd event occurs | function({event, node}) | | dragenter | Callback function for when the onDragEnter event occurs | function({event, node, expandedKeys}) | | dragleave | Callback function for when the onDragLeave event occurs | function({event, node}) | | dragover | Callback function for when the onDragOver event occurs | function({event, node}) | | dragstart | Callback function for when the onDragStart event occurs | function({event, node}) | | drop | Callback function for when the onDrop event occurs | function({event, node, dragNode, dragNodesKeys}) | | expand | Callback function for when a treeNode is expanded or collapsed | function(expandedKeys, {expanded: bool, node}) | | load | Callback function for when a treeNode is loaded | function(loadedKeys, {event, node}) | | rightClick | Callback function for when the user right clicks a treeNode | function({event, node}) | | select | Callback function for when the user clicks a treeNode | function(selectedKeys, e:{selected: bool, selectedNodes, node, event}) | ### TreeNode | Property | Description | Type | Default | Version | | --- | --- | --- | --- | --- | | class | className | string | - | | | style | style | string\|object | - | | | checkable | When Tree is checkable, set TreeNode display Checkbox or not | boolean | - | | | disableCheckbox | Disables the checkbox of the treeNode | boolean | false | | | disabled | Disables the treeNode | boolean | false | | | icon | customize icon. When you pass component, whose render will receive full TreeNode props as component props | slot\|slot-scope | - | | | isLeaf | Determines if this is a leaf node(effective when `loadData` is specified) | boolean | false | | | key | Used with (default)ExpandedKeys / (default)CheckedKeys / (default)SelectedKeys. P.S.: It must be unique in all of treeNodes of the tree! | string \| number | internal calculated position of treeNode | | | selectable | Set whether the treeNode can be selected | boolean | true | | | title | Title | string | '---' | | ### DirectoryTree props | Property | Description | Type | Default | | ------------ | ------------------------------------------------------------- | ------ | ------- | | expandAction | Directory open logic, optional `false` `'click'` `'dblclick'` | string | click | ## FAQ ### How to hide file icon when use showLine? File icon realize by using switcherIcon. You can overwrite the style to hide it