Angular TreeView Methods
This section describes members used to manipulate the widget.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
beginUpdate()
Prevents the widget from refreshing until the endUpdate() method is called.
The beginUpdate() and endUpdate() methods prevent the widget from excessive updates when you are changing multiple widget settings at once. After the beginUpdate() method is called, the widget does not update its UI until the endUpdate() method is called.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
collapseItem(itemData)
Collapses an item with a specific key.
The key.
A Promise that is resolved after the item is collapsed and rejected if the item is nonexistent or disabled.
It is a native Promise or a jQuery.Promise when you use jQuery.
collapseItem(itemElement)
Collapses an item found using its DOM node.
The item's DOM node.
A Promise that is resolved after the item is collapsed and rejected if the item is nonexistent or disabled.
It is a native Promise or a jQuery.Promise when you use jQuery.
See Also
collapseItem(key)
Collapses an item with a specific key.
The item's key.
A Promise that is resolved after the item is collapsed and rejected if the item is nonexistent or disabled.
It is a native Promise or a jQuery.Promise when you use jQuery.
defaultOptions(rule)
Specifies the device-dependent default configuration options for this component.
The component's default device options.
defaultOptions is a static method that the widget class supports. The following code demonstrates how to specify default options for all instances of the TreeView widget in an application executed on the desktop.
jQuery
DevExpress.ui.dxTreeView.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the TreeView options } });
Angular
import TreeView from "devextreme/ui/tree_view"; // ... export class AppComponent { constructor () { TreeView.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the TreeView options } }); } }
Vue
<template> <div> <DxTreeView id="treeView1" /> <DxTreeView id="treeView2" /> </div> </template> <script> import DxTreeView from "devextreme-vue/tree-view"; import TreeView from "devextreme/ui/tree_view"; TreeView.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the TreeView options } }); export default { components: { DxTreeView } } </script>
React
import React from "react"; import dxTreeView from "devextreme/ui/tree_view"; import TreeView from "devextreme-react/tree-view"; class App extends React.Component { render () { dxTreeView.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the TreeView options } }) return ( <div> <TreeView id="treeView1" /> <TreeView id="treeView2" /> </div> ) } } export default App;
dispose()
Disposes of all the resources allocated to the TreeView instance.
After calling this method, remove the DOM element associated with the widget:
$("#myTreeView").dxTreeView("dispose"); $("#myTreeView").remove();
Use this method only if the widget was created with jQuery or pure JavaScript. In Angular, Vue, and React, use conditional rendering:
Angular
<dx-tree-view ... *ngIf="condition"> </dx-tree-view>
Vue
<template> <DxTreeView ... v-if="condition"> </DxTreeView> </template> <script> import DxTreeView from 'devextreme-vue/tree-view'; export default { components: { DxTreeView } } </script>
React
import React from 'react'; import TreeView from 'devextreme-react/tree-view'; function DxTreeView(props) { if (!props.shouldRender) { return null; } return ( <TreeView ... > </TreeView> ); } class App extends React.Component { render() { return ( <DxTreeView shouldRender="condition" /> ); } } export default App;
See Also
element()
Gets the root widget element.
An HTML element or a jQuery element when you use jQuery.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
endUpdate()
Refreshes the widget after a call of the beginUpdate() method.
Main article: beginUpdate()
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
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.
The item's data object.
A Promise that is resolved after the item is expanded and rejected if the item is nonexistent or disabled.
It is a native Promise or a jQuery.Promise when you use jQuery.
expandItem(itemElement)
Expands an item found using its DOM node.
The item's DOM node.
A Promise that is resolved after the item is expanded and rejected if the item is nonexistent or disabled.
It is a native Promise or a jQuery.Promise when you use jQuery.
See Also
expandItem(key)
Expands an item with a specific key.
The item's key.
A Promise that is resolved after the item is expanded and rejected if the item is nonexistent or disabled.
It is a native Promise or a jQuery.Promise when you use jQuery.
focus()
Sets focus on the widget.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
getDataSource()
Gets the DataSource instance.
The DataSource instance.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
- Data Layer - Overview
- Data Layer - DataSource Examples
getInstance(element)
Gets the instance of a widget found using its DOM node.
The widget's instance.
getInstance is a static method that the widget class supports. The following code demonstrates how to get the TreeView instance found in an element with the myTreeView
ID:
// Modular approach import TreeView from "devextreme/ui/tree_view"; ... let element = document.getElementById("myTreeView"); let instance = TreeView.getInstance(element) as TreeView; // Non-modular approach let element = document.getElementById("myTreeView"); let instance = DevExpress.ui.dxTreeView.getInstance(element);
See Also
getNodes()
Gets all nodes.
All nodes. Their structure is described in the Node section.
instance()
Gets the widget's instance. Use it to access other methods of the widget.
This widget's instance.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
off(eventName)
Detaches all event handlers from a single event.
The event's name.
The object for which this method is called.
See Also
- Handle Events: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
off(eventName, eventHandler)
Detaches a particular event handler from a single event.
The object for which this method is called.
See Also
- Handle Events: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
on(eventName, eventHandler)
Subscribes to an event.
The object for which this method is called.
Use this method to subscribe to one of the events listed in the Events section.
See Also
- Handle Events: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
on(events)
Subscribes to events.
Events with their handlers: { "eventName1": handler1, "eventName2": handler2, ...}
The object for which this method is called.
Use this method to subscribe to several events with one method call. Available events are listed in the Events section.
See Also
- Handle Events: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
option()
Gets all widget options.
The widget's options.
See Also
- Get and Set Options
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
option(optionName)
Gets the value of a single option.
The option's name or full path.
This option's value.
See Also
- Get and Set Options
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
option(optionName, optionValue)
Updates the value of a single option.
See Also
- Get and Set Options
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
option(options)
Updates the values of several options.
Options with their new values.
See Also
- Get and Set Options
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
registerKeyHandler(key, handler)
Registers a handler to be executed when a user presses a specific key.
A key.
A handler. Accepts the keydown event as the argument. It is a dxEvent or a jQuery.Event when you use jQuery.
The key argument accepts one of the following values:
- "backspace"
- "tab"
- "enter"
- "escape"
- "pageUp"
- "pageDown"
- "end"
- "home"
- "leftArrow"
- "upArrow"
- "rightArrow"
- "downArrow"
- "del"
- "space"
- "F"
- "A"
- "asterisk"
- "minus"
A custom handler for a key cancels the default handler for this key.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
repaint()
Repaints the widget without reloading data. Call it to update the widget's markup.
See Also
- reload() in DataSource | List
- refresh() in DataGrid | TreeList
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
resetOption(optionName)
Resets an option to its default value.
An option's name.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout | ASP.NET MVC 5 | ASP.NET Core
selectItem(itemData)
Selects an item found using its data object.
The item's data object.
See Also
selectItem(itemElement)
Selects an item found using its DOM node.
The item's DOM node.
See Also
unselectItem(itemData)
Cancels the selection of an item found using its data object.
The item's data object.
See Also
unselectItem(itemElement)
Cancels the selection of an item found using its DOM node.
The item's DOM node.
See Also
unselectItem(key)
Cancels the selection of an item with a specific key.
The item's key.
See Also
updateDimensions()
Updates the tree view scrollbars according to the current size of the widget content.
A Promise that is resolved if the widget is updated and rejected otherwise. It is a native Promise or a jQuery.Promise when you use jQuery.
If you have technical questions, please create a support ticket in the DevExpress Support Center.