Reactive end-points design - reactive-programming

Question

Im learning WebFlux.
Wiki says that reactive programming is:
For example, in an imperative programming setting, a:=b+c would mean that a is being assigned the result of b+c in the instant the expression is evaluated, and later, the values of b and/or c can be changed with no effect on the value of a.
However, in reactive programming, the value of a is
automatically updated whenever the values of b and/or c change; without the program having to re-execute the sentence
a:=b+c to determine the presently assigned value of a.
Ok. When Im reproducing example like:
#RestController
public class PersonController {
private final PersonRepository repository;
public PersonController(PersonRepository repository) {
this.repository = repository;
}
#PostMapping("/person")
Mono<Void> create(#RequestBody Publisher<Person> personStream) {
return this.repository.save(personStream).then();
}
#GetMapping("/person")
Flux<Person> list() {
return this.repository.findAll();
}
#GetMapping("/person/{id}")
Mono<Person> findById(#PathVariable String id) {
return this.repository.findOne(id);
}
}
I'm Posting 2 persons. (on the chrome page 1)
Then getting list of all persons (on the chrome page 2)
Then adding one more person (on the chrome page 3)
Then I'm getting back to the page 2 (with no refreshing), I dont see updated list of persons, should I?
Also, how should work UPDATE/DELETE operations here?

Answer 1

I guess you're referring to the reactive programming wikipedia page and maybe reading too much into that example.
This example (and the famous spreadsheet one) usually point to UI rich applications that are listening to user events and publishing application events to update the UI.
Reactive programming and Reactive Streams by themselves aren't enough to set up such an infrastructure.
In your Controller, operations are performed and values are published in a reactive way: with backpressure support and access to a reactive API to compose them. Once the JSON response is rendered, the client doesn't receive new elements from the server.
You can create such a system though, by publishing events and having a persistent connection (SSE, for example) between server and browser.