RxJS Waiting for nested observable to filter array data

Question

Having two Observables : foo and bar .

foo will return an array of objects as such [{ id: 1 }, { id: 2 }, ...] (It will return the entire array (using AngularFire .list here))

bar has a stored value for each item returned from foo . The value is stored as an object as such: { id: 2, status: false } .

What needs to be done here is to call foo initially, and in it's map function, I'd like to take out { id: 2 } from the subscribe() method if its matching value in bar 's response is false .

In other terms

1. Watch stream from foo
2. .map objects and check each object status from bar
3. bar returns an observable with the value of true or false
4. . filter foo to take out any object with status as false

I've tried combineLatest , zip and other RxJS methods but not sure that I am doing this correctly. Could someone please show me the correct way or at least point our which methods I should be exploring?

Appreciate the help!

Thanks.

//

.... foo
....... itemId1
....... itemId2

.... bar
....... itemId1: true
....... itemId2: false

Upon subscribing to foo , the array it returns must be filtered to return itemId1 only, because its bar value is true (Both are observables, foo and bar ofc)

Answer 1

Here's a piece of code that gets the job done:

foo = Rx.Observable.of([
  {id: 1, data: 'foo1'}, 
  {id: 2, data: 'foo2'}, 
  {id: 3, data: 'foo3'}, 
  {id: 4, data: 'foo4'}, 
  {id: 5, data: 'foo5'}, 
  {id: 6, data: 'foo6'}
]);

bar = Rx.Observable.of([
  {id: 1, status: false}, 
  {id: 2, status: true}, 
  {id: 3, status: true}, 
  {id: 4, status: false}, 
  {id: 5, status: true}, 
  {id: 6, status: false}
]).flatMap(obj => obj);

Rx.Observable.combineLatest(foo, bar)
    .filter(([foo, bar]) => bar.status)
    .map(([foo, bar]) => foo.find(obj => obj.id === bar.id))
  .subscribe(data => {
    console.log(data)
  });