TreeViewComponent

TreeViewComponent represents the react TreeView Component.

<TreeViewComponent allowDragAndDrop={true}></TreeViewComponent>

Properties

allowDragAndDrop

boolean

Indicates whether the TreeView allows drag and drop of nodes. To drag and drop a node in desktop, hold the mouse on the node, drag it to the target node and drop the node by releasing the mouse. For touch devices, drag and drop operation is performed by touch, touch move and touch end. For more information on drag and drop nodes concept, refer to Drag and Drop.

Defaults to false

allowEditing

boolean

Enables or disables editing of the text in the TreeView node. When allowEditing property is set to true, the TreeView allows you to edit the node by double clicking the node or by navigating to the node and pressing F2 key. For more information on node editing, refer to Node Editing.

Defaults to false

allowMultiSelection

boolean

Enables or disables multi-selection of nodes. To select multiple nodes:

• Select the nodes by holding down the Ctrl key while clicking on the nodes.
• Select consecutive nodes by clicking the first node to select and hold down the Shift key and click the last node to select. For more information on multi-selection, refer to Multi-Selection.

Defaults to false

allowTextWrap

boolean

Enables or disables text wrapping when text exceeds the bounds in the TreeView node. When the allowTextWrap property is set to true, the TreeView node text content will wrap to the next line when it exceeds the width of the TreeView node. The TreeView node height will be adjusted automatically based on the TreeView node content.

Defaults to false

animation

NodeAnimationSettingsModel

Specifies the type of animation applied on expanding and collapsing the nodes along with duration.

Defaults to {expand: { effect: ‘SlideDown’, duration: 400, easing: ‘linear’ },collapse: { effect: ‘SlideUp’, duration: 400, easing: ‘linear’ }}

autoCheck

boolean

Allow us to specify the parent and child nodes to get auto check while we check or uncheck a node.

Defaults to true

checkDisabledChildren

boolean

Determines whether the disabled children will be checked or not if their parent is checked.

Defaults to true

checkedNodes

string[]

The checkedNodes property is used to set the nodes that need to be checked. This property returns the checked nodes ID in the TreeView component. The checkedNodes property depends upon the value of showCheckBox property. For more information on checkedNodes, refer to checkedNodes.

<div id="tree"></div>

let treeObj: TreeView = new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
showCheckBox: true,
checkedNodes: ['01-01','02']
});
treeObj.appendTo('#tree');

Defaults to []

cssClass

string

Specifies one or more than one CSS classes to be added with root element of the TreeView to help customize the appearance of the component.

<div id="tree"></div>

let treeObj: TreeView = new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
cssClass: 'e-custom e-tree'
});
treeObj.appendTo('#tree');

.e-custom .e-tree {
max-width: 600px;
}
.e-custom .e-list-item {
padding: 10px 0;
}

Defaults to ”

disabled

boolean

Specifies a value that indicates whether the TreeView component is disabled or not. When set to true, user interaction will not be occurred in TreeView.

Defaults to false

dragArea

HTMLElement | string

Specifies the target in which the draggable element can be moved and dropped. By default, the draggable element movement occurs in the page.

<div id="tree"></div>

let treeObj: TreeView = new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
dragArea: '.control_wrapper'
});
treeObj.appendTo('#tree');

.control_wrapper {
width: 500px;
margin-left: 100px;
}

Defaults to null

enableHtmlSanitizer

boolean

Specifies whether to display or remove the untrusted HTML values in the TreeView component. If ‘enableHtmlSanitizer’ set to true, the component will sanitize any suspected untrusted strings and scripts before rendering them.

<div id="tree"></div>

let treeObj: TreeView = new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
enableHtmlSanitizer: true
});
treeObj.appendTo('#tree');

Defaults to true

enablePersistence

boolean

Enables or disables persisting TreeView state between page reloads. If enabled, following APIs will persist.

1. selectedNodes - Represents the nodes that are selected in the TreeView component.
2. checkedNodes - Represents the nodes that are checked in the TreeView component.
3. expandedNodes - Represents the nodes that are expanded in the TreeView component.

Defaults to false

enableRtl

boolean

Enable or disable rendering component in right to left direction.

Defaults to false

expandOn

ExpandOnSettings

Specifies the action on which the node expands or collapses. The available actions : Click - The expand/collapse operation happens when you single-click on the node in desktop. DblClick - The expand/collapse operation happens when you double-click on the node in desktop. None - The expand/collapse operation will not happen. In mobile devices, the node expand/collapse action happens on single tap. Here ExpandOn attribute is set to single click property also can use double click and none property.

<div id="tree"></div>

let treeObj: TreeView = new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
expandOn: 'Click'
});
treeObj.appendTo('#tree');

Defaults to ‘Auto’

expandedNodes

string[]

Represents the expanded nodes in the TreeView component. We can set the nodes that need to be expanded or get the ID of the nodes that are currently expanded by using this property.

<div id='tree'></div>

<script>
var treeObj =  new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
expandedNodes: ['01','01-01','02']
});
treeObj.appendTo('#tree');
</script>

Defaults to []

fields

FieldsSettingsModel

Specifies the data source and mapping fields to render TreeView nodes.

Defaults to {id: ‘id’, text: ‘text’, dataSource: [], child: ‘child’, parentID: ‘parentID’, hasChildren: ‘hasChildren’, expanded: ‘expanded’, htmlAttributes: ‘htmlAttributes’, iconCss: ‘iconCss’, imageUrl: ‘imageUrl’, isChecked: ‘isChecked’, query: null, selected: ‘selected’, tableName: null, tooltip: ‘tooltip’, navigateUrl: ‘navigateUrl’}

fullRowNavigable

boolean

If this property is set to true, then the entire TreeView node will be navigate-able instead of text element.

Defaults to false

fullRowSelect

boolean

On enabling this property, the entire row of the TreeView node gets selected by clicking a node. When disabled only the corresponding node’s text gets selected. For more information on Fields concept, refer to Fields.

Defaults to true

loadOnDemand

boolean

By default, the load on demand (Lazy load) is set to true. By disabling this property, all the tree nodes are rendered at the beginning itself.

Defaults to true

nodeTemplate

string | function | JSX.Element

Specifies a template to render customized content for all the nodes. If the nodeTemplate property is set, the template content overrides the displayed node text. The property accepts template string template string or HTML element ID holding the content. For more information on template concept, refer to Template.

Defaults to null

selectedNodes

string[]

Represents the selected nodes in the TreeView component. We can set the nodes that need to be selected or get the ID of the nodes that are currently selected by using this property. On enabling allowMultiSelection property we can select multiple nodes and on disabling it we can select only a single node. For more information on selectedNodes, refer to selectedNodes.

<div id="tree"></div>

let treeObj: TreeView = new TreeView({
fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
allowMultiSelection: true,
selectedNodes: ['01','02']
});
treeObj.appendTo('#tree');

Defaults to []

showCheckBox

boolean

Indicates that the nodes will display CheckBoxes in the TreeView. The CheckBox will be displayed next to the expand/collapse icon of the node. For more information on CheckBoxes, refer to CheckBox.

Defaults to false

sortOrder

SortOrder

Specifies a value that indicates whether the nodes are sorted in the ascending or descending order, or are not sorted at all. The available types of sort order are,

• None - The nodes are not sorted.
• Ascending - The nodes are sorted in the ascending order.
• Descending - The nodes are sorted in the ascending order.

Defaults to ‘None’

Methods

addNodes

Adds the collection of TreeView nodes based on target and index position. If target node is not specified, then the nodes are added as children of the given parentID or in the root level of TreeView.

Returns void

beginEdit

Editing can also be enabled by using the beginEdit property, instead of clicking on the TreeView node. On passing the node ID or element through this property, the edit textBox will be created for the particular node thus allowing us to edit it.

Returns void

checkAll

Checks all the unchecked nodes. You can also check specific nodes by passing array of unchecked nodes as argument to this method.

Returns void

collapseAll

Collapses all the expanded TreeView nodes. You can collapse specific nodes by passing array of nodes as argument to this method. You can also collapse all the nodes excluding the hidden nodes by setting excludeHiddenNodes to true. If you want to collapse a specific level of nodes, set level as argument to collapseAll method.

Returns void

destroy

Removes the component from the DOM and detaches all its related event handlers. It also removes the attributes and classes.

Returns void

disableNodes

Disables the collection of nodes by passing the ID of nodes or node elements in the array.

Returns void

enableNodes

Enables the collection of disabled nodes by passing the ID of nodes or node elements in the array.

Returns void

ensureVisible

Ensures visibility of the TreeView node by using node ID or node element. When many TreeView nodes are present and we need to find a particular node, ensureVisible property helps bring the node to visibility by expanding the TreeView and scrolling to the specific node.

Returns void

expandAll

Expands all the collapsed TreeView nodes. You can expand the specific nodes by passing the array of collapsed nodes as argument to this method. You can also expand all the collapsed nodes by excluding the hidden nodes by setting excludeHiddenNodes to true to this method. To expand a specific level of nodes, set level as argument to expandAll method.

Returns void

getAllCheckedNodes

Gets all the checked nodes including child, whether it is loaded or not.

Returns string[]

getDisabledNodes

Gets all the disabled nodes including child, whether it is loaded or not.

Returns string[]

getNode

Gets the node’s data such as id, text, parentID, selected, isChecked, and expanded by passing the node element or it’s ID.

Returns * *{ : }**

getTreeData

To get the updated data source of TreeView after performing some operation like drag and drop, node editing, node selecting/unSelecting, node expanding/collapsing, node checking/unChecking, adding and removing node.

• If you pass the ID of TreeView node as arguments for this method then it will return the updated data source of the corresponding node otherwise it will return the entire updated data source of TreeView.
• The updated data source also contains custom attributes if you specified in data source.

Returns * { : }[]*

moveNodes

Moves the collection of nodes within the same TreeView based on target or its index position.

Returns void

refreshNode

Refreshes a particular node of the TreeView.

Returns void

removeNodes

Removes the collection of TreeView nodes by passing the array of node details as argument to this method.

Returns void

uncheckAll

Unchecks all the checked nodes. You can also uncheck the specific nodes by passing array of checked nodes as argument to this method.

Returns void

updateNode

Replaces the text of the TreeView node with the given text.

Returns void

Events

actionFailure

EmitType<FailureEventArgs>

Event callback that is raised while any TreeView action failed to fetch the desired results.

created

EmitType<Object>

Event callback that is raised when the TreeView component is created successfully.

dataBound

EmitType<DataBoundEventArgs>

Event callback that is raised when data source is populated in the TreeView.

dataSourceChanged

EmitType<DataSourceChangedEventArgs>

Event callback that is raised when data source is changed in the TreeView. The data source will be changed after performing some operation like drag and drop, node editing, adding and removing node.

destroyed

EmitType<Object>

Event callback that is raised when the TreeView control is destroyed successfully.

drawNode

EmitType<DrawNodeEventArgs>

Event callback that is raised before the TreeView node is appended to the TreeView element. It helps to customize specific nodes.

keyPress

EmitType<NodeKeyPressEventArgs>

Event callback that is raised when key press is successful. It helps to customize the operations at key press.

nodeChecked

EmitType<NodeCheckEventArgs>

Event callback that is raised when the TreeView node is checked/unchecked successfully.

nodeChecking

EmitType<NodeCheckEventArgs>

Event callback that is raised before the TreeView node is to be checked/unchecked.

nodeClicked

EmitType<NodeClickEventArgs>

Event callback that is raised when the TreeView node is clicked successfully.

nodeCollapsed

EmitType<NodeExpandEventArgs>

Event callback that is raised when the TreeView node collapses successfully.

nodeCollapsing

EmitType<NodeExpandEventArgs>

Event callback that is raised before the TreeView node collapses.

nodeDragStart

EmitType<DragAndDropEventArgs>

Event callback that is raised when the TreeView node drag (move) starts.

nodeDragStop

EmitType<DragAndDropEventArgs>

Event callback that is raised when the TreeView node drag (move) is stopped.

nodeDragging

EmitType<DragAndDropEventArgs>

Event callback that is raised when the TreeView node is dragged (moved) continuously.

nodeDropped

EmitType<DragAndDropEventArgs>

Event callback that is raised when the TreeView node is dropped on target element successfully.

nodeEdited

EmitType<NodeEditEventArgs>

Event callback that is raised when the TreeView node is renamed successfully.

nodeEditing

EmitType<NodeEditEventArgs>

Event callback that is raised before the TreeView node is renamed.

nodeExpanded

EmitType<NodeExpandEventArgs>

Event callback that is raised when the TreeView node expands successfully.

nodeExpanding

EmitType<NodeExpandEventArgs>

Event callback that is raised before the TreeView node is to be expanded.

nodeSelected

EmitType<NodeSelectEventArgs>

Event callback that is raised when the TreeView node is selected/unselected successfully.

nodeSelecting

EmitType<NodeSelectEventArgs>

Event callback that is raised before the TreeView node is selected/unselected.