Angular TreeView API

The TreeView UI component is a tree-like representation of textual data.

import { DxTreeViewModule } from "devextreme-angular"
Selector: dx-tree-view

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See Also
jQuery
Angular
Vue
React
jQuery
Angular
Vue
React

Configuration

An object defining configuration properties for the TreeView UI component.

Name Description
accessKey

Specifies the shortcut key that sets focus on the UI component.
activeStateEnabled

Specifies whether the UI component changes its visual state as a result of user interaction.
animationEnabled

Specifies whether or not to animate item collapsing and expanding.
collapseIcon

Specifies a custom collapse icon.
createChildren

Allows you to load nodes on demand.
dataSource

Binds the UI component to data.
dataStructure

Notifies the UI component of the used data structure.
disabled

Specifies whether the UI component responds to user interaction.
disabledExpr

Specifies the name of the data source item field whose value defines whether or not the corresponding UI component item is disabled.
displayExpr

Specifies the data field whose values should be displayed.
elementAttr

Specifies the global attributes to be attached to the UI component's container element.
expandAllEnabled

Specifies whether or not a user can expand all tree view items by the "*" hot key.
expandedExpr

Specifies which data source field specifies whether an item is expanded.
expandEvent

Specifies the event on which to expand/collapse a node.
expandIcon

Specifies a custom expand icon.
expandNodesRecursive

Specifies whether or not all parent nodes of an initially expanded node are displayed expanded.
focusStateEnabled

Specifies whether the UI component can be focused using keyboard navigation.
hasItemsExpr

Specifies the name of the data source item field whose value defines whether or not the corresponding node includes child nodes.
height

Specifies the UI component's height.
hint

Specifies text for a hint that appears when a user pauses on the UI component.
hoverStateEnabled

Specifies whether the UI component changes its state when a user pauses on it.
itemComponent

An alias for the itemTemplate property specified in React. Accepts a custom component. Refer to Using a Custom Component for more information.
itemHoldTimeout

The time period in milliseconds before the onItemHold event is raised.
itemRender

An alias for the itemTemplate property specified in React. Accepts a rendering function. Refer to Using a Rendering Function for more information.
items

An array of items displayed by the UI component.
itemsExpr

Specifies which data field contains nested items. Applies only if the dataStructure property is "tree".
itemTemplate

Specifies a custom template for items.
keyExpr

Specifies which data field provides keys for TreeView items.
noDataText

Specifies the text or HTML markup displayed by the UI component if the item collection is empty.
onContentReady

A function that is executed when the UI component is rendered and each time the component is repainted.
onDisposing

A function that is executed before the UI component is disposed of.
onInitialized

A function used in JavaScript frameworks to save the UI component instance.
onItemClick

A function that is executed when a collection item is clicked or tapped.
onItemCollapsed

A function that is executed when a tree view item is collapsed.
onItemContextMenu

A function that is executed when a collection item is right-clicked or pressed.
onItemExpanded

A function that is executed when a tree view item is expanded.
onItemHold

A function that is executed when a collection item has been held for a specified period.
onItemRendered

A function that is executed after a collection item is rendered.
onItemSelectionChanged

A function that is executed when a single TreeView item is selected or selection is canceled.
onOptionChanged

A function that is executed after a UI component property is changed.
onSelectAllValueChanged

A function that is executed when the "Select All" check box value is changed. Applies only if showCheckBoxesMode is "selectAll" and selectionMode is "multiple".
onSelectionChanged

A function that is executed when a TreeView item is selected or selection is canceled.
parentIdExpr

Specifies the name of the data source item field for holding the parent key of the corresponding node.
rootValue

Specifies the parent ID value of the root item.
rtlEnabled

Switches the UI component to a right-to-left representation.
scrollDirection

A string value specifying available scrolling directions.
searchEditorOptions

Configures the search panel.
searchEnabled

Specifies whether the search panel is visible.
searchExpr

Specifies a data object's field name or an expression whose value is compared to the search string.
searchMode

Specifies a comparison operation used to search UI component items.
searchTimeout

Specifies a delay in milliseconds between when a user finishes typing, and the search is executed.
searchValue

Specifies the current search string.
selectAllText

Specifies the text displayed at the "Select All" check box.
selectByClick

Specifies whether an item is selected if a user clicks it.
selectedExpr

Specifies the name of the data source item field whose value defines whether or not the corresponding UI component items is selected.
selectionMode

Specifies item selection mode. Applies only if selection is enabled.
selectNodesRecursive

Specifies whether all child nodes should be selected when their parent node is selected. Applies only if the selectionMode is "multiple".
showCheckBoxesMode

Specifies the checkbox display mode.
tabIndex

Specifies the number of the element when the Tab key is used for navigating.
useNativeScrolling

Specifies whether or not the UI component uses native scrolling.
virtualModeEnabled

Enables the virtual mode in which nodes are loaded on demand. Use it to enhance the performance on large datasets.
visible

Specifies whether the UI component is visible.
width

Specifies the UI component's width.

See Also
jQuery
Angular
Vue
React

Methods

This section describes members used to manipulate the UI component.

Name Description
beginUpdate()

Postpones rendering that can negatively affect performance until the endUpdate() method is called.
collapseAll()

Collapses all items.
collapseItem(itemData)

Collapses an item with a specific key.
collapseItem(itemElement)

Collapses an item found using its DOM node.
collapseItem(key)

Collapses an item with a specific key.
defaultOptions(rule)

Specifies the device-dependent default configuration properties for this component.
dispose()

Disposes of all the resources allocated to the TreeView instance.
element()

Gets the root UI component element.
endUpdate()

Refreshes the UI component after a call of the beginUpdate() method.
expandAll()

Expands all items. If you load items on demand, this method expands only the loaded items.
expandItem(itemData)

Expands an item found using its data object.
expandItem(itemElement)

Expands an item found using its DOM node.
expandItem(key)

Expands an item with a specific key.
focus()

Sets focus on the UI component.
getDataSource()

Gets the DataSource instance.
getInstance(element)

Gets the instance of a UI component found using its DOM node.
getNodes()

Gets all nodes.
getScrollable()

Gets the instance of the UI component's scrollable part.
getSelectedNodeKeys()

Gets the keys of selected nodes.
getSelectedNodes()

Gets selected nodes.
instance()

Gets the UI component's instance. Use it to access other methods of the UI component.
off(eventName)

Detaches all event handlers from a single event.
off(eventName, eventHandler)

Detaches a particular event handler from a single event.
on(eventName, eventHandler)

Subscribes to an event.
on(events)

Subscribes to events.
option()

Gets all UI component properties.
option(optionName)

Gets the value of a single property.
option(optionName, optionValue)

Updates the value of a single property.
option(options)

Updates the values of several properties.
registerKeyHandler(key, handler)

Registers a handler to be executed when a user presses a specific key.
repaint()

Renders the component again without reloading data. Use the method to update the component's markup and appearance dynamically.
resetOption(optionName)

Resets a property to its default value.
scrollToItem(itemData)

Scrolls the content to an item found using its data.
scrollToItem(itemElement)

Scrolls the content to an item found using its DOM node.
scrollToItem(key)

Scrolls the content to an item found using its key.
selectAll()

Selects all nodes.
selectItem(itemData)

Selects a node found using its data object.
selectItem(itemElement)

Selects a TreeView node found using its DOM node.
selectItem(key)

Selects a node with a specific key.
unselectAll()

Cancels the selection of all nodes.
unselectItem(itemData)

Cancels the selection of a node found using its data object.
unselectItem(itemElement)

Cancels the selection of a TreeView node found using its DOM node.
unselectItem(key)

Cancels the selection of a node with a specific key.
updateDimensions()

Updates the tree view scrollbars according to the current size of the UI component content.

See Also
jQuery
Angular
Vue
React

Events

This section describes events fired by this UI component.

Name Description
contentReady

Raised when the UI component's content is ready.
disposing

Raised before the UI component is disposed of.
initialized

Raised only once, after the UI component is initialized.
itemClick

Raised when a collection item is clicked or tapped.
itemCollapsed

Raised when a tree view item is collapsed.
itemContextMenu

Raised when a collection item is right-clicked or pressed.
itemExpanded

Raised when a tree view item is expanded.
itemHold

Raised when a collection item has been held for a specified period.
itemRendered

Raised after a collection item is rendered.
itemSelectionChanged

Raised when a tree view item is selected or selection is canceled.
optionChanged

Raised after a UI component property is changed.
selectAllValueChanged

Raised when the "Select All" check box value is changed.
selectionChanged

Raised when a tree view item is selected or selection is canceled.

See Also
jQuery
Angular
Vue
React

Node

A TreeView node.

import { DxTreeViewTypes } from "devextreme-angular/ui/tree-view"
Type: DxTreeViewTypes.Node

This section describes the contents of a TreeView node object. Such objects can be accessed using the getNodes() method and within functions handling the events whose name begins with item....

See Also

Types

Name Description
ContentReadyEvent

The type of the contentReady event handler's argument.
DisposingEvent

The type of the disposing event handler's argument.
InitializedEvent

The type of the initialized event handler's argument.
ItemClickEvent

The type of the itemClick event handler's argument.
ItemCollapsedEvent

The type of the itemCollapsed event handler's argument.
ItemContextMenuEvent

The type of the itemContextMenu event handler's argument.
ItemExpandedEvent

The type of the itemExpanded event handler's argument.
ItemHoldEvent

The type of the itemHold event handler's argument.
ItemRenderedEvent

The type of the itemRendered event handler's argument.
ItemSelectionChangedEvent

The type of the itemSelectionChanged event handler's argument.
OptionChangedEvent

The type of the optionChanged event handler's argument.
SelectAllValueChangedEvent

The type of the selectAllValueChanged event handler's argument.
SelectionChangedEvent

The type of the selectionChanged event handler's argument.
TreeViewCheckBoxMode

Specifies the checkbox display mode.
TreeViewExpandEvent

Specifies the event on which to expand/collapse a node.