How to iterate over a firebase2 list observable?

Question

I have a list observable of objects that I am trying to iterate over to compare a list object property to a local variable.

I can loop over the objects in the list in a template but can't see how to in the component logic.

How can I do this outside of the template?

This is the closest I have gotten to a working iterator so far.

constructor(af: AngularFire) {
    this.competitors = af.database.list('/competitors');
}
this.competitors.forEach(competitor) {
    console.log(competitor);
}

I'm sorry if this is a question is poorly constructed, I am still quite new to Angular2 and Firebase.

Answer 1

You're working with Observables and not plain collections here. This means that you have to use the Observable primitives and simple looping over this.competitors will not work.

This this:

this.competitors.subscribe(competitor => console.log(competitor));

And by the way, there is a naming convention to name Observables with a $ at the end, so it would look the following way:

this.competitors$ = af.database.list('/competitors');

and:

this.competitors$.subscribe(competitor => console.log(competitor));

This will log the entire array of competitors. If you want to iterate over the elements, do something like the following:

this.competitors.subscribe(
    competitors => {
        competitors.map(competitor =>
            console.log(competitor)
        )
    });