Accessibility Features Overview
| Accessibility Requirement | Support Level | 
|---|---|
| Right-to-Left Support | |
| Keyboard Navigation Support | |
| Screen Reader Support | |
| Contrast Color Theme | |
| Mobile Device Support | |
| Lighthouse Accessibility Validation | |
| Axe Accessibility Validation | |
| WAVE Accessibility Validation | |
| Section 508 Support | |
| WCAG 2.x Support | 
- - All component features meet the requirement
- - Some component features may not meet the requirement
- - Accessibility requirement is not supported
Accessibility Standards Compliance
The NumberBox component meets a variety of Section 508 and WCAG 2.x compliance standards. Known exceptions:
| Section 508 criteria | WCAG 2.x criteria | Exception description | 
|---|---|---|
| 501 (Web)(Software) 504.2 (Authoring Tool) 602.3 (Support Docs) | 1.4.3 Contrast (Minimum) (Level AA) 1.4.11 Non-text Contrast (Level AA 2.1 and 2.2) | NumberBox does not support Windows High Contrast themes. | 
| - | 2.5.8 Target Size (Minimum) (Level AA 2.2 only) | A spin button. | 
Keyboard Navigation
A user can use the following keys to interact with the NumberBox component:
| Key | Action | 
|---|---|
| ↑ or mouse wheel up | Increases the UI component value by a step. | 
| ↓ or mouse wheel down | Decreases the UI component value by a step. | 
Use the registerKeyHandler(key, handler) method to implement a custom handler for a key.
jQuery
function registerKeyHandlers () {
    const numberBox = $("#numberBoxContainer").dxNumberBox("instance");
    numberBox.registerKeyHandler("backspace", function(e) {
        // The argument "e" contains information on the event
    });
    numberBox.registerKeyHandler("space", function(e) {
        // ...
    });
}Angular
import { ..., ViewChild, AfterViewInit } from '@angular/core';
import { DxNumberBoxModule, DxNumberBoxComponent } from 'devextreme-angular';
// ...
export class AppComponent implements AfterViewInit {
    @ViewChild(DxNumberBoxComponent, { static: false }) numberBox: DxNumberBoxComponent;
    // Prior to Angular 8
    // @ViewChild(DxNumberBoxComponent) numberBox: DxNumberBoxComponent;
    ngAfterViewInit () {
        this.numberBox.instance.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.numberBox.instance.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxNumberBoxModule
    ],
    // ...
})Vue
<template>
    <DxNumberBox :ref="myNumberBoxRef" />
</template>
<script>
import 'devextreme/dist/css/dx.light.css';
import DxNumberBox from 'devextreme-vue/number-box';
const myNumberBoxRef = 'my-number-box';
export default {
    components: {
        DxNumberBox
    },
    data() {
        return {
            myNumberBoxRef
        }
    },
    computed: {
        numberBox: function() {
            return this.$refs[myNumberBoxRef].instance;
        }
    },
    mounted: function() {
        this.numberBox.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.numberBox.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
</script>React
import React from 'react';
import 'devextreme/dist/css/dx.light.css';
import { NumberBox } from 'devextreme-react/number-box';
class App extends React.Component {
    constructor(props) {
        super(props);
        this.numberBoxRef = React.createRef();
    }
    render() {
        return (
            <NumberBox ref={this.numberBoxRef} />
        );
    }
    get numberBox() {
        return this.numberBoxRef.current.instance();
    }
    componentDidMount() {
        this.numberBox.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.numberBox.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
export default App;Screen Reader Support
The NumberBox component supports screen readers and complies to WAI-ARIA standards.
To improve accessibility, use the inputAttr property to specify aria-label for the component. You do not need to specify aria-label if you use the label option.
If you have technical questions, please create a support ticket in the DevExpress Support Center.