import { Component , OnDestroy } from '@angular/core' ; import { NbThemeService } from '@nebular/theme' ; @ Component ( { selector : 'ngx-kitten' , styleUrls : [ './kitten.component.scss' ] , templateUrl : './kitten.component.html' , } ) export class KittenComponent implements OnDestroy { currentTheme : string ; themeSubscription : any ; constructor ( private themeService ) { this . themeSubscription = this . themeService . getJsTheme ( ) . subscribe ( theme => { this . currentTheme = theme . name ; } ) ; } ngOnDestroy ( ) { this . themeSubscription . unsubscribe ( ) ; } }