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 Button UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxButton.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Button properties } });
Angular
import Button, { Properties } from "devextreme/ui/button"; // ... export class AppComponent { constructor () { Button.defaultOptions<Properties>({ device: { deviceType: "desktop" }, options: { // Here go the Button properties } }); } }
Vue
<template> <div> <DxButton id="button1" /> <DxButton id="button2" /> </div> </template> <script> import DxButton from "devextreme-vue/button"; import Button from "devextreme/ui/button"; Button.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Button properties } }); export default { components: { DxButton } } </script>
React
import dxButton from "devextreme/ui/button"; import Button from "devextreme-react/button"; dxButton.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Button properties } }); export default function App() { return ( <div> <Button id="button1" /> <Button id="button2" /> </div> ) }
You can also set rules for multiple device types:
jQuery
DevExpress.ui.dxButton.defaultOptions({ device: [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ], options: { // Here go the Button properties } });
Angular
import Button, { Properties } from "devextreme/ui/button"; // ... export class AppComponent { constructor () { Button.defaultOptions<Properties>({ device: [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ], options: { // Here go the Button properties } }); } }
Vue
<template> <div> <DxButton id="button1" /> <DxButton id="button2" /> </div> </template> <script> import DxButton from "devextreme-vue/button"; import Button from "devextreme/ui/button"; Button.defaultOptions({ device: [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ], options: { // Here go the Button properties } }); export default { components: { DxButton } } </script>
React
import dxButton from "devextreme/ui/button"; import Button from "devextreme-react/button"; dxButton.defaultOptions({ device: [ { deviceType: 'desktop' }, { deviceType: 'tablet' }, { deviceType: 'phone' }, ], options: { // Here go the Button properties } }); export default function App() { return ( <div> <Button id="button1" /> <Button id="button2" /> </div> ) }
dispose()
jQuery
After calling this method, remove the DOM element associated with the UI component:
$("#myButton").dxButton("dispose"); $("#myButton").remove();
Angular
Use conditional rendering instead of this method:
<dx-button ... *ngIf="condition"> </dx-button>
Vue
Use conditional rendering instead of this method:
<template> <DxButton ... v-if="condition"> </DxButton> </template> <script> import DxButton from 'devextreme-vue/button'; export default { components: { DxButton } } </script>
React
Use conditional rendering instead of this method:
import React from 'react'; import Button from 'devextreme-react/button'; function DxButton(props) { if (!props.shouldRender) { return null; } return ( <Button ... > </Button> ); } class App extends React.Component { render() { return ( <DxButton 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 Button instance found in an element with the myButton
ID:
// Modular approach import Button from "devextreme/ui/button"; ... let element = document.getElementById("myButton"); let instance = Button.getInstance(element) as Button; // Non-modular approach let element = document.getElementById("myButton"); let instance = DevExpress.ui.dxButton.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.
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
If you have technical questions, please create a support ticket in the DevExpress Support Center.