Hi have 2 observables ,

1. this.resolveActifsFromStore() // return Observable
2. this.store.select(fromActifSelector.DoSelector.selectAllActifs) // return Observable<IActifModel[]>

I need to execute by order, so I use the concatWith like this

actifs$!: Observable<IActifModel[]>;

ngOnInit(){
    this.resolveActifsFromStore()
    .pipe(        
        concatWith(this.store.select(fromActifSelector.DoSelector.selectAllActifs)),
    )        
    .subscribe((val)=>{ 
              //error first return is boolean , the second is  IActifModel[]
              //HERE IS I DON´T KNOW HOW TO DO 
              if(val) { 
                        actifs$ = of(val);
                      } 
}

The problem is the val will have the return boolean, and also IActifModel[]. How can I identify the type of each return, because I want to do this, if the first observables is true then I want to assign the value of the second observable to actifs$

CodePudding user response：

You can use Array.isArray. It inferes the type correctly and knows within the if block, that the type of val is an array.(https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray)

.subscribe((val: boolean | IActifModel[])=>{ 
    if(Array.isArray(val)) {
      // code for IActifModel[]
    } else {
      // code for boolean
    }

CodePudding user response：

You could use concatMap to wait for the first observable to complete and then proceed to the second one:

this.resolveActifsFromStore().pipe(
  withLatestFrom(this.store.select(fromActifSelector.DoSelector.selectAllActifs),
  concatMap(([myBoolean, myIActifModel]: [boolean, IActifModel[]]) => {
    //....
    return of({
       theBoolean: myBoolean,
       theOtherOne: myIActifModel
    });
  })
).subscribe(console.log);