import { Injectable } from '@angular/core'; import { BehaviorSubject } from 'rxjs'; export interface IDropdownState { visible?: boolean | 'toggle'; dropdown?: any; } @Injectable() export class DropdownService { private dropdownState = new BehaviorSubject({}); dropdownState$ = this.dropdownState.asObservable(); constructor() { } toggle(state: IDropdownState): void { this.dropdownState.next(state); } }