scan
RxJS 5 scan
by Brian Troncone
HTML
<script src="https://npmcdn.com/@reactivex/[email protected]/dist/global/Rx.umd.js"></script>
JavaScript
const subject = new Rx.Subject();
//scan example building an object over time
const example = subject.scan((acc, curr) => Object.assign({}, acc, curr), {});
//log accumulated values
const subscribe = example.subscribe(val => console.log('Accumulated object:', val));
//next values into subject, adding properties to object
subject.next({name: 'Joe'}); // {name: 'Joe'}
subject.next({age: 30}); // {name: 'Joe', age: 30}
subject.next({favoriteLanguage: 'JavaScript'}); // {name: 'Joe', age: 30, favoriteLanguage: 'JavaScript'}