Rxjs get distinct values of property value in array

问题

I am trying to get distinct values of a property in an observable array.

  let pt$ = Observable.of([{planTypeID : 1, description : 'test 1'}, 
                                {planTypeID : 2, description : 'test 2'}]);
    let planTypeIDs$ = pt$
        .flatMap(a => a)
        .map(a => a.planTypeID).distinct().toArray();

Is this the right way to do it in rxjs, or is there a better way?

回答1:

1. You could use .from instead of .of, that should spare you the .flatMap
2. distinct will check the reference by default, so if you want to compare for contents you should create some kind of hash or make a custom comparer - but maybe that's not required here.

---

let pt$ = Observable.from([{planTypeID : 1, description : 'test 1'}, 
                            {planTypeID : 2, description : 'test 2'}]);
let planTypeIDs$ = pt$
    .map(a => a.planTypeID)
    .distinct()
    .toArray();

来源：https://stackoverflow.com/questions/41961982/rxjs-get-distinct-values-of-property-value-in-array