JavaScript/jQuery Draggable Methods

Methods of the DomComponent object.

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.

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.

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 Draggable UI component in an application executed on the desktop.

jQuery

JavaScript

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

Angular

TypeScript

import Draggable, { Properties } from "devextreme/ui/draggable";
// ...
export class AppComponent {
    constructor () {
        Draggable.defaultOptions<Properties>({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Draggable properties
            }
        });
    }
}

Vue

<template>
    <div>
        <DxDraggable id="draggable1" />
        <DxDraggable id="draggable2" />
    </div>
</template>
<script>
import DxDraggable from "devextreme-vue/draggable";
import Draggable from "devextreme/ui/draggable";

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

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

React

import dxDraggable from "devextreme/ui/draggable";
import Draggable from "devextreme-react/draggable";

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

export default function App() {
    return (
        <div>
            <Draggable id="draggable1" />
            <Draggable id="draggable2" />
        </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.dxDraggable.defaultOptions({ 
        device: deviceConfig,
        options: {
            // Here go the Draggable properties
        }
    });
});

Angular

TypeScript

import Draggable, { Properties } from "devextreme/ui/draggable";
// ...
export class AppComponent {
    constructor () {
        const devicesConfig = [
            { deviceType: 'desktop' },
            { deviceType: 'tablet' },
            { deviceType: 'phone' },
        ];

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

Vue

<template>
    <div>
        <DxDraggable />
    </div>
</template>
<script>
import DxDraggable from "devextreme-vue/draggable";
import Draggable from "devextreme/ui/draggable";

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

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

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

React

import dxDraggable from "devextreme/ui/draggable";
import Draggable from "devextreme-react/draggable";

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

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

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

dispose()

Disposes of all the resources allocated to the Draggable instance.

jQuery

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

JavaScript

$("#myDraggable").dxDraggable("dispose");
$("#myDraggable").remove();

Angular

Use conditional rendering instead of this method:

app.component.html

<dx-draggable ...
    *ngIf="condition">
</dx-draggable>

Vue

Use conditional rendering instead of this method:

App.vue

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

<script>
import DxDraggable from 'devextreme-vue/draggable';

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

React

Use conditional rendering instead of this method:

App.js

import React from 'react';

import Draggable from 'devextreme-react/draggable';

function DxDraggable(props) {
    if (!props.shouldRender) {
        return null;
    }

    return (
        <Draggable ... >    
        </Draggable>
    );
}

class App extends React.Component {
    render() {
        return (
            <DxDraggable 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.

jQuery

Call Methods

Angular

Call Methods

Vue

Call Methods

React

Call Methods

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.

jQuery

Call Methods

Angular

Call Methods

Vue

Call Methods

React

Call Methods

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 Draggable instance found in an element with the myDraggable ID:

// Modular approach
import Draggable from "devextreme/ui/draggable";
...
let element = document.getElementById("myDraggable");
let instance = Draggable.getInstance(element) as Draggable;

// Non-modular approach
let element = document.getElementById("myDraggable");
let instance = DevExpress.ui.dxDraggable.getInstance(element);