Course Notes ngjs

Subjects

Implment a Store Service

src/app/common/store.service.ts make the service injectable
should contain a courses$ Observable from a Subject
init store via app.component.ts -> onInit()
use Store from home.compontent
test it
add new select...() methods in the store , and refactor home.comp to use it

implment save operation

course dialoge: save button
save it to in-memory , emit new value to all subscribers, then asynchronouse save to backend
make the Store.save() method also a Observable (fromPromise(fetch())), so the subscription in course-dialoge can close the dialogue or show an error in the console
copy the in-memory courses and replace the new data,
call backend
refactor course.compoent to use the store