beginUpdate()
Prevents the UI component from refreshing until the endUpdate() method is called.
The beginUpdate() and endUpdate() methods prevent the UI component from excessive updates when you are changing multiple UI component settings at once. After the beginUpdate() method is called, the UI component does not update its UI until the endUpdate() method is called.
See Also
defaultOptions(rule)
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 DropDownBox UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxDropDownBox.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownBox properties
}
});Angular
import DropDownBox from "devextreme/ui/drop_down_box";
// ...
export class AppComponent {
constructor () {
DropDownBox.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownBox properties
}
});
}
}Vue
<template>
<div>
<DxDropDownBox id="dropDownBox1" />
<DxDropDownBox id="dropDownBox2" />
</div>
</template>
<script>
import DxDropDownBox from "devextreme-vue/drop-down-box";
import DropDownBox from "devextreme/ui/drop_down_box";
DropDownBox.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownBox properties
}
});
export default {
components: {
DxDropDownBox
}
}
</script>React
import React, {useEffect} from "react";
import dxDropDownBox from "devextreme/ui/drop_down_box";
import DropDownBox from "devextreme-react/drop-down-box";
export default function App() {
useEffect(() => {
dxDropDownBox.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownBox properties
}
})
});
return (
<div>
<DropDownBox id="dropDownBox1" />
<DropDownBox id="dropDownBox2" />
</div>
)
}dispose()
After calling this method, remove the DOM element associated with the UI component:
$("#myDropDownBox").dxDropDownBox("dispose");
$("#myDropDownBox").remove();Use this method only if the UI component was created with jQuery or pure JavaScript. In Angular, Vue, and React, use conditional rendering:
Angular
<dx-drop-down-box ...
*ngIf="condition">
</dx-drop-down-box>Vue
<template>
<DxDropDownBox ...
v-if="condition">
</DxDropDownBox>
</template>
<script>
import DxDropDownBox from 'devextreme-vue/drop-down-box';
export default {
components: {
DxDropDownBox
}
}
</script>React
import React from 'react';
import DropDownBox from 'devextreme-react/drop-down-box';
function DxDropDownBox(props) {
if (!props.shouldRender) {
return null;
}
return (
<DropDownBox ... >
</DropDownBox>
);
}
class App extends React.Component {
render() {
return (
<DxDropDownBox shouldRender="condition" />
);
}
}
export default App;See Also
getButton(name)
Gets an instance of a custom action button.
Use the returned button instance to call the Button UI component's methods, for example, focus():
jQuery
const myCustomButton = $("#dropDownBoxContainer").dxDropDownBox("getButton", "myCustomButton");
myCustomButton.focus();Angular
import { Component, ViewChild } from '@angular/core';
import { DxDropDownBoxComponent } from 'devextreme-angular';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
@ViewChild('dropDownBoxRef', { static: false }) dropDownBox: DxDropDownBoxComponent;
// Prior to Angular 8
// @ViewChild('dropDownBoxRef') dropDownBox: DxDropDownBoxComponent;
setFocus() {
this.dropDownBox.instance.getButton('myCustomButton').focus();
}
}<dx-drop-down-box #dropDownBoxRef ... > </dx-drop-down-box>
Vue
<template>
<DxDropDownBox ...
:ref="dropDownBoxRef">
</DxDropDownBox>
</template>
<script>
import 'devextreme/dist/css/dx.light.css';
import DxDropDownBox from 'devextreme-vue/drop-down-box';
export default {
components: {
DxDropDownBox
},
data() {
return {
dropDownBoxRef
}
},
methods: {
setFocus() {
this.dropDownBox.getButton('myCustomButton').focus();
}
},
computed: {
dropDownBox: function() {
return this.$refs[dropDownBoxRef].instance;
}
}
}
</script>React
import React from 'react';
import 'devextreme/dist/css/dx.light.css';
import DropDownBox from 'devextreme-react/drop-down-box';
class App extends React.Component {
constructor(props) {
super(props);
this.dropDownBoxRef = React.createRef();
this.setFocus = () => {
this.dropDownBox.getButton('myCustomButton').focus();
};
}
get dropDownBox() {
return this.dropDownBoxRef.current.instance;
}
render() {
return (
<DropDownBox ...
ref={this.dropDownBoxRef}>
</DropDownBox>
);
}
}
export default App;getDataSource()
Gets the DataSource instance.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout
- Data Layer - Overview
- Data Layer - DataSource Examples
getInstance(element)
getInstance is a static method that the UI component class supports. The following code demonstrates how to get the DropDownBox instance found in an element with the myDropDownBox ID:
// Modular approach
import DropDownBox from "devextreme/ui/drop_down_box";
...
let element = document.getElementById("myDropDownBox");
let instance = DropDownBox.getInstance(element) as DropDownBox;
// Non-modular approach
let element = document.getElementById("myDropDownBox");
let instance = DevExpress.ui.dxDropDownBox.getInstance(element);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.