Update view for NgIf Else Directive

update_view_method.ts

private _updateView() {
    if (this._context.$implicit) {
      if (!this._thenViewRef) {
        this._viewContainer.clear();
        this._elseViewRef = null;
        if (this._thenTemplateRef) {
          this._thenViewRef =
              this._viewContainer.createEmbeddedView(this._thenTemplateRef, this._context);
        }
      }
    } else {
      if (!this._elseViewRef) {
        this._viewContainer.clear();
        this._thenViewRef = null;
        if (this._elseTemplateRef) {
          this._elseViewRef =
              this._viewContainer.createEmbeddedView(this._elseTemplateRef, this._context);
        }
      }
    }
  }