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
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 Draggable UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxDraggable.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Draggable properties } });
Angular
import Draggable, { Properties } from "devextreme/ui/draggable"; // ... export class AppComponent { constructor () { Draggable.defaultOptions<Properties>({ device: { deviceType: "desktop" }, options: { // Here go the Draggable properties } }); } }
Vue
<template> <div> <DxDraggable id="draggable1" /> <DxDraggable id="draggable2" /> </div> </template> <script> import DxDraggable from "devextreme-vue/draggable"; import Draggable from "devextreme/ui/draggable"; Draggable.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Draggable properties } }); export default { components: { DxDraggable } } </script>
React
import dxDraggable from "devextreme/ui/draggable"; import Draggable from "devextreme-react/draggable"; dxDraggable.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Draggable properties } }); export default function App() { return ( <div> <Draggable id="draggable1" /> <Draggable id="draggable2" /> </div> ) }
You can also set rules for multiple device types:
jQuery
const devicesConfig = [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ]; devicesConfig.forEach(deviceConfig => { DevExpress.ui.dxDraggable.defaultOptions({ device: deviceConfig, options: { // Here go the Draggable properties } }); });
Angular
import Draggable, { Properties } from "devextreme/ui/draggable"; // ... export class AppComponent { constructor () { const devicesConfig = [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ]; devicesConfig.forEach(deviceConfig => { Draggable.defaultOptions<Properties>({ device: deviceConfig, options: { // Here go the Draggable properties } }); }); } }
Vue
<template> <div> <DxDraggable /> </div> </template> <script> import DxDraggable from "devextreme-vue/draggable"; import Draggable from "devextreme/ui/draggable"; const devicesConfig = [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ]; devicesConfig.forEach(deviceConfig => { Draggable.defaultOptions({ device: deviceConfig, options: { // Here go the Draggable properties } }); }); export default { components: { DxDraggable } } </script>
React
import dxDraggable from "devextreme/ui/draggable"; import Draggable from "devextreme-react/draggable"; const devicesConfig = [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ]; devicesConfig.forEach(deviceConfig => { dxDraggable.defaultOptions({ device: deviceConfig, options: { // Here go the Draggable properties } }); }); export default function App() { return ( <div> <Draggable /> </div> ) }
dispose()
jQuery
After calling this method, remove the DOM element associated with the UI component:
$("#myDraggable").dxDraggable("dispose"); $("#myDraggable").remove();
Angular
Use conditional rendering instead of this method:
<dx-draggable ... *ngIf="condition"> </dx-draggable>
Vue
Use conditional rendering instead of this method:
<template> <DxDraggable ... v-if="condition"> </DxDraggable> </template> <script> import DxDraggable from 'devextreme-vue/draggable'; export default { components: { DxDraggable } } </script>
React
Use conditional rendering instead of this method:
import React from 'react'; import Draggable from 'devextreme-react/draggable'; function DxDraggable(props) { if (!props.shouldRender) { return null; } return ( <Draggable ... > </Draggable> ); } class App extends React.Component { render() { return ( <DxDraggable 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
getInstance(element)
getInstance is a static method that the UI component class supports. The following code demonstrates how to get the Draggable instance found in an element with the myDraggable
ID:
// Modular approach import Draggable from "devextreme/ui/draggable"; ... let element = document.getElementById("myDraggable"); let instance = Draggable.getInstance(element) as Draggable; // Non-modular approach let element = document.getElementById("myDraggable"); let instance = DevExpress.ui.dxDraggable.getInstance(element);
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.