Angular Lookup - Keyboard Support

An end user can use the following keys to interact with the UI component.

Key Action
Alt + ↓ Opens the drop-down menu.
Enter or Space If the drop-down menu is closed, opens it; otherwise selects the current item.
Esc Closes the drop-down menu.
↑ / ↓ If the drop-down menu is opened, moves focus to the previous/next item.
Tab / Shift + Tab If the drop-down menu is opened, moves focus to the list / search field.
Page Up / Page Down Moves focus to the first/last menu item on the page.
Home / End Moves focus to the first/last menu item.

You can implement a custom handler for a key using the registerKeyHandler(key, handler) method.

jQuery
JavaScript
function registerKeyHandlers () {
    const lookup = $("#lookupContainer").dxLookup("instance");
    lookup.registerKeyHandler("backspace", function(e) {
        // The argument "e" contains information on the event
    });
    lookup.registerKeyHandler("space", function(e) {
        // ...
    });
}
Angular
TypeScript
import { ..., ViewChild, AfterViewInit } from '@angular/core';
import { DxLookupModule, DxLookupComponent } from 'devextreme-angular';
// ...
export class AppComponent implements AfterViewInit {
    @ViewChild(DxLookupComponent, { static: false }) lookup: DxLookupComponent;
    // Prior to Angular 8
    // @ViewChild(DxLookupComponent) lookup: DxLookupComponent;

    ngAfterViewInit () {
        this.lookup.instance.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.lookup.instance.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})
Vue
<template>
    <DxLookup :ref="myLookupRef" />
</template>
<script>
import 'devextreme/dist/css/dx.light.css';

import DxLookup from 'devextreme-vue/lookup';

const myLookupRef = 'my-lookup';

export default {
    components: {
        DxLookup
    },
    data() {
        return {
            myLookupRef
        }
    },
    computed: {
        lookup: function() {
            return this.$refs[myLookupRef].instance;
        }
    },
    mounted: function() {
        this.lookup.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.lookup.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}
</script>
React
App.js
import React from 'react';
import 'devextreme/dist/css/dx.light.css';

import { Lookup } from 'devextreme-react/lookup';

class App extends React.Component {
    constructor(props) {
        super(props);

        this.lookupRef = React.createRef();
    }

    render() {
        return (
            <Lookup ref={this.lookupRef} />
        );
    }

    get lookup() {
        return this.lookupRef.current.instance;
    }

    componentDidMount() {
        this.lookup.registerKeyHandler('backspace', function(e) {
            // The argument "e" contains information on the event
        });
        this.lookup.registerKeyHandler('space', function(e) {
            // ...
        });
    }
}

export default App;
See Also