Type Ahead

By adamlubek

This recipe demonstrates the creation of type ahead client side code.

Ultimate RxJS

Example Code

( StackBlitz )

Typeahead
// RxJS v6+
import { fromEvent, of } from 'rxjs';
import {
debounceTime,
distinctUntilChanged,
map,
switchMap,
tap
} from 'rxjs/operators';
const getContinents = keys =>
[
'africa',
'antarctica',
'asia',
'australia',
'europe',
'north america',
'south america'
].filter(e => e.indexOf(keys.toLowerCase()) > -1);
const fakeContinentsRequest = keys =>
of(getContinents(keys)).pipe(
tap(_ => console.log(`API CALL at ${new Date()}`))
);
fromEvent(document.getElementById('type-ahead'), 'keyup')
.pipe(
debounceTime(200),
map((e: any) => e.target.value),
distinctUntilChanged(),
switchMap(fakeContinentsRequest),
tap(c => (document.getElementById('output').innerText = c.join('\n')))
)
.subscribe();

html

Get continents
<input id="type-ahead" />
<hr />
<div id="output"></div>

Operators Used