JavaScript/jQuery TreeView Methods
beginUpdate()
Postpones rendering that can negatively affect performance until the endUpdate() method is called.
The beginUpdate() and endUpdate() methods reduce the number of renders in cases where extra rendering can negatively affect performance.
See Also
collapseItem(itemData)
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)
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(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)
| Name | Type | Description |
|---|---|---|
| device | | |
Device parameters. |
| options |
Options to be applied. |
defaultOptions is a static method that the UI component class supports. The following code demonstrates how to specify default properties for all instances of the TreeView UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxTreeView.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the TreeView properties
}
});Angular
import TreeView, { Properties } from "devextreme/ui/tree_view";
// ...
export class AppComponent {
constructor () {
TreeView.defaultOptions<Properties>({
device: { deviceType: "desktop" },
options: {
// Here go the TreeView properties
}
});
}
}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 properties
}
});
export default {
components: {
DxTreeView
}
}
</script>React
import dxTreeView from "devextreme/ui/tree_view";
import TreeView from "devextreme-react/tree-view";
dxTreeView.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the TreeView properties
}
});
export default function App() {
return (
<div>
<TreeView id="treeView1" />
<TreeView id="treeView2" />
</div>
)
}You can also set rules for multiple device types:
jQuery
DevExpress.ui.dxTreeView.defaultOptions({
device: [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
],
options: {
// Here go the TreeView properties
}
});Angular
import TreeView, { Properties } from "devextreme/ui/tree_view";
// ...
export class AppComponent {
constructor () {
TreeView.defaultOptions<Properties>({
device: [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
],
options: {
// Here go the TreeView properties
}
});
}
}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' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
],
options: {
// Here go the TreeView properties
}
});
export default {
components: {
DxTreeView
}
}
</script>React
import dxTreeView from "devextreme/ui/tree_view";
import TreeView from "devextreme-react/tree-view";
dxTreeView.defaultOptions({
device: [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
],
options: {
// Here go the TreeView properties
}
});
export default function App() {
return (
<div>
<TreeView id="treeView1" />
<TreeView id="treeView2" />
</div>
)
}dispose()
jQuery
After calling this method, remove the DOM element associated with the UI component:
$("#myTreeView").dxTreeView("dispose");
$("#myTreeView").remove();Angular
Use conditional rendering instead of this method:
<dx-tree-view ...
*ngIf="condition">
</dx-tree-view>Vue
Use conditional rendering instead of this method:
<template>
<DxTreeView ...
v-if="condition">
</DxTreeView>
</template>
<script>
import DxTreeView from 'devextreme-vue/tree-view';
export default {
components: {
DxTreeView
}
}
</script>React
Use conditional rendering instead of this method:
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;endUpdate()
Refreshes the UI component after a call of the beginUpdate() method.
The beginUpdate() and endUpdate() methods reduce the number of renders in cases where extra rendering can negatively affect performance.
See Also
expandAll()
Expands all items. If you load items on demand, this method expands only the loaded items.
expandItem(itemData)
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)
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(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.
getDataSource()
Gets the DataSource instance.
See Also
getInstance(element)
getInstance is a static method that the UI component 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
getScrollable()
For information on API members of the scrollable part, refer to the ScrollView section. The list below shows ScrollView members that are unavailable for this method.
Properties:
- pullingDownText
- pulledDownText
- refreshingText
- reachBottomText
- onPullDown
- onReachBottom
Methods:
- release(preventScrollBottom)
- refresh()
See Also
getSelectedNodeKeys()
Array<any>
See Also
getSelectedNodes()
jQuery
const selectedNodes = $("#treeViewContainer").dxTreeView("getSelectedNodes");Angular
import { Component, ViewChild } from '@angular/core';
import { DxTreeViewComponent } from 'devextreme-angular';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
@ViewChild('treeViewRef', { static: false }) treeView: DxTreeViewComponent;
// Prior to Angular 8
// @ViewChild('treeViewRef') treeView: DxTreeViewComponent;
selectedNodes = [];
getSelectedNodes() {
this.selectedNodes = this.treeView.instance.getSelectedNodes();
}
}
<dx-tree-view ...
#treeViewRef>
</dx-tree-view>
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
import { DxTreeViewModule } from 'devextreme-angular';
@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
DxTreeViewModule
],
providers: [ ],
bootstrap: [AppComponent]
})
export class AppModule { }Vue
<template>
<DxTreeView ...
:ref="treeViewRef">
</DxTreeView>
</template>
<script>
import 'devextreme/dist/css/dx.light.css';
import DxTreeView from 'devextreme-vue/tree-view';
export default {
components: {
DxTreeView
},
data() {
return {
treeViewRef,
selectedNodes: []
}
},
computed: {
treeView: function() {
return this.$refs[treeViewRef].instance;
}
},
methods: {
getSelectedNodes() {
this.selectedNodes = this.treeView.getSelectedNodes();
}
}
}
</script>React
import React from 'react';
import 'devextreme/dist/css/dx.light.css';
import TreeView from 'devextreme-react/tree-view';
class App extends React.Component {
constructor(props) {
super(props);
this.treeViewRef = React.createRef();
this.selectedNodes = [];
this.getSelectedNodes = () => {
this.selectedNodes = this.treeView.getSelectedNodes();
}
}
get treeView() {
return this.treeViewRef.current.instance;
}
render() {
return (
<TreeView ...
ref={this.treeViewRef}>
</TreeView>
);
}
}
export default App;See Also
on(eventName, eventHandler)
Use this method to subscribe to one of the events listed in the Events section.
See Also
on(events)
Use this method to subscribe to several events with one method call. Available events are listed in the Events section.
See Also
registerKeyHandler(key, handler)
A handler. Accepts the keydown event as the argument. It is a EventObject 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
repaint()
The method repaints Toolbar and re-initializes all its items.
See Also
- reload() in DataSource | List
- refresh() in DataGrid | TreeList
scrollToItem(itemData)
A Promise that is resolved after the content is scrolled to the target item and rejected if the item is nonexsistent or nested in a collapsed and disabled node.
It is a native Promise or a jQuery.Promise when you use jQuery.
scrollToItem(itemElement)
A Promise that is resolved after the content is scrolled to the target item and rejected if the item is nonexsistent or nested in a collapsed and disabled node.
It is a native Promise or a jQuery.Promise when you use jQuery.
scrollToItem(key)
A Promise that is resolved after the content is scrolled to the target item and rejected if the item is nonexsistent or nested in a collapsed and disabled node.
It is a native Promise or a jQuery.Promise when you use jQuery.
selectAll()
This method has the following specificities:
Only loaded nodes can be selected. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, only the nodes that satisfy the search condition can be selected.
See Also
selectItem(itemData)
This method has the following specificities:
Only loaded nodes can be selected. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, only the nodes that satisfy the search condition can be selected.
See Also
selectItem(itemElement)
This method has the following specificities:
Only loaded nodes can be selected. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, only the nodes that satisfy the search condition can be selected.
See Also
selectItem(key)
This method has the following specificities:
Only loaded nodes can be selected. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, only the nodes that satisfy the search condition can be selected.
See Also
unselectAll()
This method has the following specificities:
The selection of only loaded nodes can be canceled. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, this method cancels the selection of only those nodes that satisfy the search condition.
See Also
unselectItem(itemData)
This method has the following specificities:
The selection of only loaded nodes can be canceled. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, this method cancels the selection of only those nodes that satisfy the search condition.
See Also
unselectItem(itemElement)
This method has the following specificities:
The selection of only loaded nodes can be canceled. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, this method cancels the selection of only those nodes that satisfy the search condition.
See Also
unselectItem(key)
This method has the following specificities:
The selection of only loaded nodes can be canceled. Take this specificity into account if nodes are loaded on demand (for example, if you use the virtual mode or createChildren function).
If searching is applied, this method cancels the selection of only those nodes that satisfy the search condition.
See Also
updateDimensions()
A Promise that is resolved if the UI component 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.