When I try to pass a BehaviorSubject from my CacheService to a component @Input() that expects an array, I encounter an error stating that 'any[] | Type 'any[] | null' is not assignable to type 'any[]'. This occurs even though the BehaviorSubject is initialized with an empty array as the default value in the service. I'm puzzled by this issue and have provided a condensed version of my app below to demonstrate the problem. Any assistance would be greatly appreciated.
app.component.html
<app-custom-select [options]="this.items$ | async"></app-custom-select>
app.component.ts
import { Component } from '@angular/core';
import { FormControl, FormGroup } from '@angular/forms';
import { BehaviorSubject, ReplaySubject, Subject } from 'rxjs';
import { CacheService } from './services/cache.service';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: './app.component.scss'
})
export class AppComponent
{
items$ = this.cache.items.data$;
constructor(private cache: CacheService) {}
}
cache.service.ts
import { Injectable } from '@angular/core';
import { CacheArray } from '../models/CacheArray';
@Injectable({
providedIn: 'root'
})
export class CacheService
{
items = new CacheArray<any>();
}
cache.ts
import { BehaviorSubject, Observable } from "rxjs";
export class CacheArray<T>
{
data$ = new BehaviorSubject<T[]>([]);
load(obs: Observable<T[]>)
{
obs.subscribe((items: T[]) => {
this.data$.next(items);
});
}
}
custom-select.component.ts
import { Component, Input, OnInit } from '@angular/core';
@Component({
selector: 'app-custom-select',
templateUrl: './custom-select.component.html',
styleUrls: ['./custom-select.component.scss']
})
export class CustomSelectComponent
{
@Input()
options: any[] = [];
}
I did not anticipate encountering this error.