TreeView

A widget displaying specified data items as a tree.

Included in: dx.webappjs.js, dx.all.js

You can create a widget using one of the following approaches.

  • jQuery
    Use the dxTreeView jQuery plug-in.

    HTML
    <div id="treeView"></div>
    JavaScript
    var treeViewData = [
        { id: 1, parentId: 0, text: "Animals" },
        { id: 2, parentId: 1, text: "Cat" },
        { id: 3, parentId: 1, text: "Dog" },
        { id: 4, parentId: 1, text: "Cow" },
        { id: 5, parentId: 2, text: "Abyssinian" },
        { id: 6, parentId: 2, text: "Aegean cat" },
        { id: 7, parentId: 2, text: "Australian Mist" },
        { id: 8, parentId: 3, text: "Affenpinscher" },
        { id: 9, parentId: 3, text: "Afghan Hound" },
        { id: 10, parentId: 3, text: "Airedale Terrier" },
        { id: 11, parentId: 3, text: "Akita Inu" },
        { id: 12, parentId: 0, text: "Birds" },
        { id: 13, parentId: 12, text: "Akekee" },
        { id: 14, parentId: 12, text: "Arizona Woodpecker" },
        { id: 15, parentId: 12, text: "Black-chinned Sparrow" }
    ];
    $("#treeView").dxTreeView({
        dataSource: treeViewData,
        dataStructure: 'plain'
    });
  • Knockout
    Add a div element and apply the dxTreeView binding to this element.

    HTML
    <div data-bind="dxTreeView: {
        dataSource: treeViewData,
        dataStructure: 'plain'
    }"></div>
  • Angular
    Add a div element and apply the dx-tree-view directive to this element.

    HTML
    <div dx-tree-view="{
        dataSource: treeViewData,
        dataStructure: 'plain'
    }"></div>

Note that DevExtreme widgets require you to link the jQuery and Globalize libraries to your application. If you use the Knockout or Angular approach, the Knockout or Angular library is also required.

See Also

Since the dxTreeView widget is used to display multiple items, it supports common Collection Container widget functionality. You can find detailed information on the principles of working with the widget in the dxTreeView section of the Collection Container Widgets article.

NOTE
The dxTreeView widget requires each data source item to contain at least a key field. Thus, the widget does not support data sources consisting of value items.

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Configuration

An object defining configuration options for the dxTreeView widget.

Name Description
accessKey

Specifies a shortcut key that sets focus on the widget element.

activeStateEnabled

A Boolean value specifying whether or not the widget changes its state when interacting with a user.

animationEnabled

Specifies whether or not to animate item collapsing and expanding.

dataSource

A data source used to fetch data to be displayed by the widget.

dataStructure

Specifies whether a nested or plain array is used as a data source.

disabled

A Boolean value specifying whether or not the widget can respond to user interaction.

disabledExpr

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

displayExpr

Specifies the name of the data source item field whose value is displayed by the widget.

expandAllEnabled

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

expandedExpr

Specifies the name of the data source item field whose value defines whether or not the corresponding node is expanded.

focusStateEnabled

Specifies whether or not the widget can be focused.

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 height of the widget.

hint

Specifies the text of the hint displayed for the widget.

hoverStateEnabled

A Boolean value specifying whether or not the widget changes its state when being hovered by an end user.

itemHoldTimeout

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

items

An array of items displayed by the widget.

itemsExpr

Specifies the name of the data source item field that contains an array of nested items.

itemTemplate

The template to be used for rendering items.

keyExpr

Specifies the name of the data source item field used as a key.

noDataText

The text or HTML markup displayed by the widget if the item collection is empty.

onContentReady

A handler for the contentReady event.

onDisposing

A handler for the disposing event.

onInitialized

A handler for the initialized event.

onItemClick

A handler for the itemClick event.

onItemCollapsed

A handler for the itemCollapsed event.

onItemContextMenu

A handler for the itemContextMenu event.

onItemExpanded

A handler for the itemExpanded event.

onItemHold

A handler for the itemHold event.

onItemRendered

A handler for the itemRendered event.

onItemSelected

A handler for the itemSelected event.

onOptionChanged

A handler for the optionChanged event.

onSelectionChanged

A handler for the selectionChanged event.

parentIdExpr

Specifies the name of the data source item field that holds the key of the parent item.

rootValue

Specifies the parent ID value of the root item.

rtlEnabled

Specifies whether or not the current component supports a right-to-left representation.

scrollDirection

A string value specifying available scrolling directions.

selectAllEnabled

Specifies whether the "Select All" check box is displayed over the tree view.

selectAllText

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

selectedExpr

Specifies the name of the data source item field whose value defines whether or not the corresponding node is selected.

selectNodesRecursive

Specifies whether or not to select nodes recursively.

showCheckBoxes

Specifies whether or not a check box is displayed at each tree view item.

tabIndex

Specifies the widget tab index.

virtualModeEnabled

Specifies if the virtual mode is enabled.

visible

A Boolean value specifying whether or not the widget is visible.

width

Specifies the width of the widget.

Methods

This section describes members used to manipulate the widget.

Name Description
beginUpdate()

Prevents the component from refreshing until the endUpdate method is called.

collapseItem(itemElement)

Collapses the specified item.

defaultOptions(rule)

Specifies the device-dependent default configuration options for this component.

element()

Returns the root HTML element of the widget.

endUpdate()

Enables the component to refresh after the beginUpdate method call.

expandItem(itemElement)

Expands the specified item.

focus()

Sets focus on the widget.

getNodes()

Returns all nodes of the tree view.

instance()

Returns an instance of this component class.

off(eventName)

Detaches all event handlers from the specified event.

off(eventName, eventHandler)

Detaches a particular event handler from the specified event.

on(eventName, eventHandler)

Subscribes to a specified event.

on(events)

Subscribes to the specified events.

option()

Returns the configuration options of this component.

option(optionName)

Gets the value of the specified configuration option of this component.

option(optionName, optionValue)

Sets a value to the specified configuration option of this component.

option(options)

Sets one or more options of this component.

registerKeyHandler(key, handler)

Registers a handler when a specified key is pressed.

repaint()

Redraws the widget.

selectAll()

Selects all widget items.

selectItem(itemElement)

Selects the specified item.

unselectAll()

Unselects all widget items.

unselectItem(itemElement)

Unselects the specified item.

updateDimensions()

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

Events

This section describes events exposed by this widget.

Name Description
contentReady

Fires when widget content is ready.

disposing

Fires when the widget is being removed.

initialized

Fires when the widget is initialized.

itemClick

Fires when a widget item is clicked.

itemCollapsed

Fires when a tree view item is collapsed.

itemContextMenu

Fires when the the right mouse button is clicked when the pointer is over a widget item, or when the "sustained" (also known as a long press) touch action is performed.

itemExpanded

Fires when a tree view item is expanded.

itemHold

Fires when the widget's collection item is being held for the time period specified by the itemHoldTimeout option.

itemRendered

Fires after a collection item is rendered.

itemSelected

Fires when a tree view item is selected.

optionChanged

Fires after an option of the component is changed.

selectionChanged

Fires after a collection item is selected or unselected.

Default Item Template

This section lists the data source fields that are used in a default item template.

By default, a predefined item template is applied to display the items of this widget. This template is based on certain fields of the data source provided for this widget. Below is the list of these fields. If the default item template is not appropriate for your task, implement a custom item template based on these or other fields of your data source.

See Also