jQuery DropDownBox Methods

This section describes members used to manipulate data.

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

blur()

Removes focus from the input element.

See Also

clear()

Resets the value property to the default value.

close()

Closes the drop-down editor.

See Also

content()

Gets the popup window's content.

Return Value:

HTMLElement | jQuery

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

See Also

defaultOptions(rule)

Specifies the device-dependent default configuration properties for this component.

Parameters:
rule:

Object

The component's default device properties.

Object structure:
Name Type Description
device

Device

|

Function

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

options

Object

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 DropDownBox UI component in an application executed on the desktop.

jQuery
JavaScript
DevExpress.ui.dxDropDownBox.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the DropDownBox properties
    }
});
Angular
TypeScript
import DropDownBox, { Properties } from "devextreme/ui/drop_down_box";
// ...
export class AppComponent {
    constructor () {
        DropDownBox.defaultOptions<Properties>({
            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 dxDropDownBox from "devextreme/ui/drop_down_box";
import DropDownBox from "devextreme-react/drop-down-box";

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

export default function App() {
    return (
        <div>
            <DropDownBox id="dropDownBox1" />
            <DropDownBox id="dropDownBox2" />
        </div>
    )
}

You can also set rules for multiple device types:

jQuery
JavaScript
const devicesConfig = [
    { deviceType: 'desktop' },
    { deviceType: 'tablet' },
    { deviceType: 'phone' },
];

devicesConfig.forEach(deviceConfig => {
    DevExpress.ui.dxDropDownBox.defaultOptions({ 
        device: deviceConfig,
        options: {
            // Here go the DropDownBox properties
        }
    });
});
Angular
TypeScript
import DropDownBox, { Properties } from "devextreme/ui/drop_down_box";
// ...
export class AppComponent {
    constructor () {
        const devicesConfig = [
            { deviceType: 'desktop' },
            { deviceType: 'tablet' },
            { deviceType: 'phone' },
        ];

        devicesConfig.forEach(deviceConfig => {
            DropDownBox.defaultOptions<Properties>({
                device: deviceConfig,
                options: {
                    // Here go the DropDownBox properties
                }
            });
        });
    }
}
Vue
<template>
    <div>
        <DxDropDownBox />
    </div>
</template>
<script>
import DxDropDownBox from "devextreme-vue/drop-down-box";
import DropDownBox from "devextreme/ui/drop_down_box";

const devicesConfig = [
    { deviceType: 'desktop' },
    { deviceType: 'tablet' },
    { deviceType: 'phone' },
];

devicesConfig.forEach(deviceConfig => {
    DropDownBox.defaultOptions({
        device: deviceConfig,
        options: {
            // Here go the DropDownBox properties
        }
    });
});

export default {
    components: {
        DxDropDownBox
    }
}
</script>
React
import dxDropDownBox from "devextreme/ui/drop_down_box";
import DropDownBox from "devextreme-react/drop-down-box";

const devicesConfig = [
    { deviceType: 'desktop' },
    { deviceType: 'tablet' },
    { deviceType: 'phone' },
];

devicesConfig.forEach(deviceConfig => {
    dxDropDownBox.defaultOptions({
        device: deviceConfig,
        options: {
            // Here go the DropDownBox properties
        }
    });
});

export default function App() {
    return (
        <div>
            <DropDownBox />
        </div>
    )
}

dispose()

Disposes of all the resources allocated to the DropDownBox instance.

jQuery

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

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

Use conditional rendering instead of this method:

app.component.html
<dx-drop-down-box ...
    *ngIf="condition">
</dx-drop-down-box>
Vue

Use conditional rendering instead of this method:

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

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

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

Use conditional rendering instead of this method:

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 UI component element.

Return Value:

HTMLElement | jQuery

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

See Also

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

field()

Gets the UI component's <input> element.

Return Value:

HTMLElement | jQuery

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

See Also

focus()

Sets focus to the input element representing the UI component.

See Also

getButton(name)

Gets an instance of a custom action button.

Parameters:
name:

String

The button's name.

Return Value:

Button

| undefined

The Button UI component's instance.

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

jQuery
index.js
const 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.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.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 UI component's dataSource property was given a simple array.

View on GitHub

See Also

getInstance(element)

Gets the instance of a UI component found using its DOM node.

Parameters:
element:

Element

|

jQuery

The UI component's container.

Return Value:

Object

The UI component's instance.

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

instance()

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

Return Value:

DropDownBox

This UI component's instance.

See Also

off(eventName)

Detaches all event handlers from a single event.

Parameters:
eventName:

String

The event's name.

Return Value:

DropDownBox

The object for which this method is called.

See Also

off(eventName, eventHandler)

Detaches a particular event handler from a single event.

Parameters:
eventName:

String

The event's name.

eventHandler:

Function

The event's handler.

Return Value:

DropDownBox

The object for which this method is called.

See Also

on(eventName, eventHandler)

Subscribes to an event.

Parameters:
eventName:

String

The event's name.

eventHandler:

Function

The event's handler.

Return Value:

DropDownBox

The object for which this method is called.

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

See Also

on(events)

Subscribes to events.

Parameters:
events:

Object

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

Return Value:

DropDownBox

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.

See Also

open()

Opens the drop-down editor.

See Also

option()

Return Value:

Object

The UI component's properties.

option(optionName)

Gets the value of a single property.

Parameters:
optionName:

String

The property's name or full path.

Return Value: any

This property's value.

option(optionName, optionValue)

Updates the value of a single property.

Parameters:
optionName:

String

The property's name or full path.

optionValue: any

This property's new value.

option(options)

Updates the values of several properties.

Parameters:
options:

Object

Options with their new values.

registerKeyHandler(key, handler)

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

Parameters:
key:

String

A key.

handler:

Function

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.

View on GitHub

See Also

reset()

Resets the value property to the initial value.

This method sets the isDirty flag to false.

See Also

reset(value)

Resets the value property to the value passed as an argument.

Parameters:
value:

String

Specifies the new value.

This method sets the isDirty flag to false.

See Also

resetOption(optionName)

Resets a property to its default value.

Parameters:
optionName:

String

A property's name.

See Also