React Menu Methods

This section describes members used to manipulate the widget.

beginUpdate()

Prevents the widget from refreshing until the endUpdate() method is called.

The beginUpdate() and endUpdate() methods prevent the widget from excessive updates when you are changing multiple widget settings at once. After the beginUpdate() method is called, the widget does not update its UI until the endUpdate() method is called.

See Also

defaultOptions(rule)

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

Parameters:
rule:

Object

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.

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

jQuery
JavaScript
DevExpress.ui.dxMenu.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the Menu options
    }
});
Angular
TypeScript
import Menu from 'devextreme/ui/menu';
// ...
export class AppComponent {
    constructor () {
        Menu.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Menu options
            }
        });
    }
}

dispose()

Disposes of all the resources allocated to the Menu instance.

The following code disposes of an Menu instance that corresponds to the element ID (or reference variable in Angular) and removes the element from the DOM:

jQuery
JavaScript
$("#myMenu").dxMenu("dispose");
$("#myMenu").remove();
Angular
HTML
<dx-menu #menuVar id="myMenu"></dx-menu>
TypeScript
import { ..., ViewChild } from "@angular/core";
import { DxMenuComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild("menuVar") menu: DxMenuComponent;

    removeMenu (e) {
        this.menu.instance.dispose();
        document.getElementById("myMenu").remove();
    }
}

element()

Gets the root widget element.

Return Value:

HTMLElement | jQuery

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

See Also

endUpdate()

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

Main article: beginUpdate()

See Also

focus()

Sets focus on the widget.

See Also

getDataSource()

Gets the DataSource instance.

Return Value:

DataSource

See Also

getInstance(element)

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

Parameters:
element:

DOM Node

|

jQuery

The widget's container.

Return Value:

Object

The widget's instance.

getInstance is a static method that the widget class supports. The following code demonstrates how to get the Menu instance found in an element with the myMenu ID:

// Modular approach
import Menu from 'devextreme/ui/menu';
...
let element = document.getElementById("myMenu");
let instance = Menu.getInstance(element) as Menu;

// Non-modular approach
let element = document.getElementById("myMenu");
let instance = DevExpress.ui.dxMenu.getInstance(element);
See Also

instance()

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

Return Value:

Object

This widget's instance.

See Also

off(eventName)

Detaches all event handlers from a single event.

Parameters:
eventName:

String

The event's name.

Return Value:

Object

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:

Object

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:

Object

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:

Object

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

option()

Gets all widget options.

Return Value:

Object

The widget's options.

option(optionName)

Gets the value of a single option.

Parameters:
optionName:

String

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:

String

The option's name or full path.

optionValue: any

This option's new value.

option(options)

Updates the values of several options.

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

The key.

handler:

Function

The handler.

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()

Repaints the widget. Call it if you made modifications that changed the widget's state to invalid.

See Also

selectItem(itemElement)

Selects an item found using its DOM node.

Parameters:
itemElement:

DOM Node

The item's DOM node.

See Also

unselectItem(itemElement)

Cancels the selection of an item found using its DOM node.

Parameters:
itemElement:

DOM Node

The item's DOM node.

See Also