JavaScript/jQuery DropDownBox Methods

The component's default device options.

Object structure:

Name	Type	Description
device	Device \| Array<Device> \| Function	Device parameters. When specifying a function, get information about the current device from the argument. Return true if the options should be applied to the device.
options	Object	Options to be applied.

Name

Type

Description

device

Device

|

Array<Device>

|

Device parameters.
When specifying a function, get information about the current device from the argument. Return true if the options should be applied to the device.

options

Options to be applied.

defaultOptions is a static method that the widget class supports. The following code demonstrates how to specify default options for all instances of the DropDownBox widget in an application executed on the desktop.

jQuery

JavaScript

DevExpress.ui.dxDropDownBox.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the DropDownBox options
    }
});

Angular

TypeScript

import DropDownBox from "devextreme/ui/drop_down_box";
// ...
export class AppComponent {
    constructor () {
        DropDownBox.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the DropDownBox options
            }
        });
    }
}

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 options
    }
});

export default {
    components: {
        DxDropDownBox
    }
}
</script>

React

import React from "react";
import dxDropDownBox from "devextreme/ui/drop_down_box";
import DropDownBox from "devextreme-react/drop-down-box";

class App extends React.Component {
    render () {
        dxDropDownBox.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the DropDownBox options
            }
        })
        return (
            <div>
                <DropDownBox id="dropDownBox1" />
                <DropDownBox id="dropDownBox2" />
            </div>
        )
    }
}

export default App;

dispose()

Disposes of all the resources allocated to the DropDownBox instance.

After calling this method, remove the DOM element associated with the widget:

JavaScript

$("#myDropDownBox").dxDropDownBox("dispose");
$("#myDropDownBox").remove();

Use this method only if the widget was created with jQuery or pure JavaScript. In Angular, Vue, and React, use conditional rendering:

Angular

app.component.html

<dx-drop-down-box ...
    *ngIf="condition">
</dx-drop-down-box>

Vue

App.vue

<template>
    <DxDropDownBox ...
        v-if="condition">
    </DxDropDownBox>
</template>

<script>
import DxDropDownBox from 'devextreme-vue/drop-down-box';

export default {
    components: {
        DxDropDownBox
    }
}
</script>

React

App.js

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;

element()

Gets the root widget element.

Return Value:

HTMLElement | jQuery

An HTML element or a jQuery element when you use jQuery.

endUpdate()

Refreshes the widget after a call of the beginUpdate() method.

Main article: beginUpdate()

field()

Gets the widget's <input> element.

Return Value:

HTMLElement | jQuery

An HTML element or a jQuery element when you use jQuery.

focus()

Sets focus to the input element representing the widget.

getButton(name)

Gets an instance of a custom action button.

Parameters:

name:

The button's name.

Return Value:

Button

| undefined

The Button widget's instance.

Use the returned button instance to call the Button widget's methods, for example, focus():

jQuery

index.js

var myCustomButton = $("#dropDownBoxContainer").dxDropDownBox("getButton", "myCustomButton");
myCustomButton.focus();

Angular

app.component.ts

app.component.html

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

App.vue

<template>
    <DxDropDownBox ...
        :ref="dropDownBoxRef">
    </DxDropDownBox>
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
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

App.js

import React from 'react';

import 'devextreme/dist/css/dx.common.css';
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.

Return Value:

DataSource

The DataSource instance.

NOTE

This method returns the DataSource instance even if the widget's dataSource option was given a simple array.

getInstance(element)

Gets the instance of a widget found using its DOM node.

Parameters:

element:

Element

|

jQuery

The widget's container.

Return Value:

The widget's instance.

getInstance is a static method that the widget 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);

instance()

Gets the widget's instance. Use it to access other methods of the widget.

Return Value:

This widget's instance.

off(eventName)

Detaches all event handlers from a single event.

Parameters:

eventName:

The event's name.

Return Value:

The object for which this method is called.

off(eventName, eventHandler)

Detaches a particular event handler from a single event.

Parameters:

eventName:

The event's name.

eventHandler:

The event's handler.

Return Value:

The object for which this method is called.

on(eventName, eventHandler)

Subscribes to an event.

Parameters:

eventName:

The event's name.

eventHandler:

The event's handler.

Return Value:

The object for which this method is called.

Use this method to subscribe to one of the events listed in the Events section.

on(events)

Subscribes to events.

Parameters:

events:

Events with their handlers: { "eventName1": handler1, "eventName2": handler2, ...}

Return Value:

The object for which this method is called.

Use this method to subscribe to several events with one method call. Available events are listed in the Events section.

open()

Opens the drop-down editor.

option()

Gets all widget options.

Return Value:

The widget's options.

option(optionName)

Gets the value of a single option.

Parameters:

optionName:

The option's name or full path.

Return Value: any

This option's value.

option(optionName, optionValue)

Updates the value of a single option.

Parameters:

optionName:

The option's name or full path.

optionValue: any

This option's new value.

option(options)

Updates the values of several options.

Parameters:

options:

Options with their new values.

registerKeyHandler(key, handler)

Registers a handler to be executed when a user presses a specific key.

Parameters:

key:

A key.

handler:

A handler. Accepts the keydown event as the argument. It is a dxEvent 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.

repaint()

Repaints the widget without reloading data. Call it to update the widget's markup.

reset()

Resets the value option to the default value.

resetOption(optionName)

Resets an option to its default value.

Parameters:

optionName: