@angular/core#Optional TypeScript Examples

constructor(
    @Host() @Self() @Optional() private readonly matPag: MatPaginator,
    private readonly ViewContainer: ViewContainerRef,
    private readonly renderer: Renderer2
  ) {
    this.currentPage = 1;
    this.pageGapTxt = ['•••', '---'];
    this.showTotalPages = 3;
    this.checkPage = [0, 0, 0];
    // Display custom range label text
    this.matPag._intl.getRangeLabel = (page: number, pageSize: number, length: number): string => {
      const startIndex = page * pageSize;
      const endIndex = startIndex < length ?
        Math.min(startIndex + pageSize, length) :
        startIndex + pageSize;
      return length > 0 ? 'Showing ' + (startIndex + 1) + ' – ' + endIndex + ' of ' + length + ' records' : 'Showing 0 – 0 of 0 records';
    };
    // Subscribe to rerender buttons when next page and last page button is used
    this.matPag.page.subscribe((paginator: PageEvent) => {
      this.currentPage = paginator.pageIndex;
      this.matPag.pageIndex = paginator.pageIndex;
      this.initPageRange();
    });
  }

constructor(
    @Optional() @SkipSelf() @Inject(LG_ACCORDION) public accordion: LgAccordionComponent,
    private selectionDispatcher: UniqueSelectionDispatcher,
    private cdr: ChangeDetectorRef,
  ) {
    this._removeSingleItemSelectionListener = selectionDispatcher.listen(
      (id: string, accordionId: string) => {
        if (
          accordion &&
          !accordion.multi &&
          accordion.id === accordionId &&
          this._id !== id
        ) {
          this.isActive = false;
          this.accordionPanelHeading.isActive = false;

          this.closed.emit();
          this.cdr.markForCheck();
        }
      },
    );
  }

constructor(
    @Optional() @Inject(DYNAMICHOOKS_GLOBALSETTINGS) private globalSettings: DynamicHooksGlobalSettings,
    private parserEntryResolver: ParserEntryResolver,
    private optionsResolver: OptionsResolver,
    private hooksReplacer: HooksReplacer,
    private componentCreator: ComponentCreator,
    private rendererFactory: RendererFactory2,
    private injector: Injector
  ) {
    this.renderer = rendererFactory.createRenderer(null, null);
  }

constructor(protected httpClient: HttpClient, @Optional()@Inject(BASE_PATH) basePath: string, @Optional() configuration: Configuration) {
        if (basePath) {
            this.basePath = basePath;
        }
        if (configuration) {
            this.configuration = configuration;
            this.basePath = basePath || configuration.basePath || this.basePath;
        }
    }

constructor(
    @Inject(DOCUMENT) private document: Document,
    // eslint-disable-next-line @typescript-eslint/ban-types
    @Inject(PLATFORM_ID) private platformId: Object,
    @Inject(REQUEST) @Optional() private request: Request,
    @Inject(RESPONSE) @Optional() private response: Response,
  ) {
    this.isBrowser = isPlatformBrowser(platformId)
  }

constructor(
    @Optional() private _config: DynamicBrowserTitleConfig,
    private _router: Router,
    @Inject(DOCUMENT) private document: any,
    private _titleService: Title
  ) {
    this._document = this.document as Document;
    this.init();
    const titleElem: HTMLElement = this._document.querySelector('title');
    this._defaultTitle = titleElem?.innerText || '';
  }

constructor(
    overlay: Overlay,
    viewContainerRef: ViewContainerRef,
    elRef: ElementRef<HTMLInputElement>,
    renderer: Renderer2,
    cdr: ChangeDetectorRef,
    ngZone: NgZone,
    @Optional()
    @Host()
    private readonly ngControl: NgControl,
  ) {
    super(overlay, viewContainerRef, elRef, renderer, cdr, ngZone);
    this.type = TooltipType.Plain;
    this.trigger = TooltipTrigger.Manual;
    this.position = 'bottom start';
    this.hideOnClick = true;
  }

constructor(
    public element: ElementRef,
    public router: Router,
    public renderer: Renderer2,
    @Optional()
    @Inject(LINK_ACTIVE_OPTIONS)
    private defaultActiveOptions: LinkActiveOptions,
    @Optional() private link: LinkTo
  ) {}

constructor(protected httpClient: HttpClient, @Optional()@Inject(BASE_PATH) basePath: string, @Optional() configuration: Configuration) {
        if (configuration) {
            this.configuration = configuration;
        }
        if (typeof this.configuration.basePath !== 'string') {
            if (typeof basePath !== 'string') {
                basePath = this.basePath;
            }
            this.configuration.basePath = basePath;
        }
        this.encoder = this.configuration.encoder || new CustomHttpParameterCodec();
    }

constructor(
        private readonly router: Router,
        private setup: SetupService,
        @Inject(DOCUMENT) private readonly document: any,
        @Optional() @Inject(APP_TITLE) private readonly appTitle: any) {

        if (!TitleService.singletonInstance) {
            this.initialize();
            TitleService.singletonInstance = this;
        }

        return TitleService.singletonInstance;
    }

constructor(
    private utils: CssUtils,
    private cdRef: ChangeDetectorRef,
    @Optional() public bgProviderService?: BackgroundProviderService
  ) {
    this.bgProviderService.$changeColor.subscribe((value) => {
      if (value === "dark") {
        this.lightBackground = false;
        this.darkBackground = true;
      } else if (value === "light") {
        this.lightBackground = true;
        this.darkBackground = false;
      }
      this.className = `${this.getDynamicStyle(this.defaultInputs.getValue())}`;
    });
  }

constructor(@Optional() @Inject(DOCUMENT) document: any) {
    this.supportsSvg = !!(
      document &&
      document.createElementNS &&
      document.createElementNS('http://www.w3.org/2000/svg', 'svg').createSVGRect
    );

    this.base = document && document.head.querySelector('base');
    this.hasPerf =
      typeof window !== 'undefined' &&
      window.performance &&
      window.performance.now &&
      typeof window.performance.now() === 'number';
  }

constructor(
        private readonly router: Router,
        @Inject(DOCUMENT) private readonly document: any,
        @Optional() @Inject(APP_TITLE) private readonly appTitle: any) {

        if (!TitleService.singletonInstance) {
            this.initialize();
            TitleService.singletonInstance = this;
        }

        return TitleService.singletonInstance;
    }

constructor(
    protected httpClient: HttpClient,
    @Optional() @Inject(BASE_PATH) basePath: string,
    @Optional() configuration: Configuration
  ) {
    if (configuration) {
      this.configuration = configuration
    }
    if (typeof this.configuration.basePath !== 'string') {
      if (typeof basePath !== 'string') {
        basePath = this.basePath
      }
      this.configuration.basePath = basePath
    }
    this.encoder = this.configuration.encoder || new CustomHttpParameterCodec()
  }