JavaScript/jQuery DropDownButton 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
close()
A Promise that is resolved when the drop-down menu is closed. 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 DropDownButton UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxDropDownButton.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownButton properties
}
});Angular
import DropDownButton, { Properties } from "devextreme/ui/drop_down_button";
// ...
export class AppComponent {
constructor () {
DropDownButton.defaultOptions<Properties>({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownButton properties
}
});
}
}Vue
<template>
<div>
<DxDropDownButton id="dropDownButton1" />
<DxDropDownButton id="dropDownButton2" />
</div>
</template>
<script>
import DxDropDownButton from "devextreme-vue/drop-down-button";
import DropDownButton from "devextreme/ui/drop_down_button";
DropDownButton.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownButton properties
}
});
export default {
components: {
DxDropDownButton
}
}
</script>React
import dxDropDownButton from "devextreme/ui/drop_down_button";
import DropDownButton from "devextreme-react/drop-down-button";
dxDropDownButton.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the DropDownButton properties
}
});
export default function App() {
return (
<div>
<DropDownButton id="dropDownButton1" />
<DropDownButton id="dropDownButton2" />
</div>
)
}You can also set rules for multiple device types:
jQuery
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
DevExpress.ui.dxDropDownButton.defaultOptions({
device: deviceConfig,
options: {
// Here go the DropDownButton properties
}
});
});Angular
import DropDownButton, { Properties } from "devextreme/ui/drop_down_button";
// ...
export class AppComponent {
constructor () {
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
DropDownButton.defaultOptions<Properties>({
device: deviceConfig,
options: {
// Here go the DropDownButton properties
}
});
});
}
}Vue
<template>
<div>
<DxDropDownButton />
</div>
</template>
<script>
import DxDropDownButton from "devextreme-vue/drop-down-button";
import DropDownButton from "devextreme/ui/drop_down_button";
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
DropDownButton.defaultOptions({
device: deviceConfig,
options: {
// Here go the DropDownButton properties
}
});
});
export default {
components: {
DxDropDownButton
}
}
</script>React
import dxDropDownButton from "devextreme/ui/drop_down_button";
import DropDownButton from "devextreme-react/drop-down-button";
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
dxDropDownButton.defaultOptions({
device: deviceConfig,
options: {
// Here go the DropDownButton properties
}
});
});
export default function App() {
return (
<div>
<DropDownButton />
</div>
)
}dispose()
jQuery
After calling this method, remove the DOM element associated with the UI component:
$("#myDropDownButton").dxDropDownButton("dispose");
$("#myDropDownButton").remove();Angular
Use conditional rendering instead of this method:
<dx-drop-down-button ...
*ngIf="condition">
</dx-drop-down-button>Vue
Use conditional rendering instead of this method:
<template>
<DxDropDownButton ...
v-if="condition">
</DxDropDownButton>
</template>
<script>
import DxDropDownButton from 'devextreme-vue/drop-down-button';
export default {
components: {
DxDropDownButton
}
}
</script>React
Use conditional rendering instead of this method:
import React from 'react';
import DropDownButton from 'devextreme-react/drop-down-button';
function DxDropDownButton(props) {
if (!props.shouldRender) {
return null;
}
return (
<DropDownButton ... >
</DropDownButton>
);
}
class App extends React.Component {
render() {
return (
<DxDropDownButton 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
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 DropDownButton instance found in an element with the myDropDownButton ID:
// Modular approach
import DropDownButton from "devextreme/ui/drop_down_button";
...
let element = document.getElementById("myDropDownButton");
let instance = DropDownButton.getInstance(element) as DropDownButton;
// Non-modular approach
let element = document.getElementById("myDropDownButton");
let instance = DevExpress.ui.dxDropDownButton.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
open()
A Promise that is resolved when the drop-down menu is opened. It is a native Promise or a jQuery.Promise when you use jQuery.
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()
Renders the component again without reloading data. Use the method to update the component's markup and appearance dynamically.
The repaint() method re-initializes the component with new settings, resetting its state and history.
See Also
- reload() in DataSource | List
- refresh() in DataGrid | TreeList
toggle()
A Promise that is resolved when the drop-down menu is opened or closed. It is a native Promise or a jQuery.Promise when you use jQuery.
toggle(visibility)
A Promise that is resolved when the drop-down menu is opened or closed. It is a native Promise or a jQuery.Promise when you use jQuery.