Rock.Model.PageService.CanDelete C# (CSharp) Method

        public bool CanDelete( Page item, out string errorMessage, bool includeSecondLvl )
        {
            errorMessage = string.Empty;

            bool canDelete = CanDelete( item, out errorMessage );

            var site = new Service<Site>( this.Context ).Queryable().Where( s => ( s.DefaultPageId == item.Id || s.LoginPageId == item.Id
                || s.RegistrationPageId == item.Id || s.PageNotFoundPageId == item.Id ) ).FirstOrDefault();
            if ( canDelete && includeSecondLvl && site != null )
            {
                errorMessage = string.Format( "This {0} is used by a special page on the {1} {2}.", Page.FriendlyTypeName, site.Name, Site.FriendlyTypeName );
                canDelete = false;
            }

            return canDelete;
        }

        /// <summary>
        /// Handles the Delete event of the gPages control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="RowEventArgs" /> instance containing the event data.</param>
        protected void gPages_Delete( object sender, RowEventArgs e )
        {
            var rockContext = new RockContext();
            PageService pageService = new PageService( rockContext );
            var pageViewService = new PageViewService(rockContext);
            var siteService = new SiteService(rockContext);

            Rock.Model.Page page = pageService.Get( new Guid( e.RowKeyValue.ToString() ) );
            if ( page != null )
            {
                string errorMessage;
                if ( !pageService.CanDelete( page, out errorMessage, includeSecondLvl: true ) )
                {
                    mdGridWarning.Show( errorMessage, ModalAlertType.Alert );
                    return;
                }

                foreach (var site in siteService.Queryable())
                {
                    if (site.DefaultPageId == page.Id)
                    {
                        site.DefaultPageId = null;
                        site.DefaultPageRouteId = null;
                    }
                    if (site.LoginPageId == page.Id)
                    {
                        site.LoginPageId = null;
                        site.LoginPageRouteId = null;
                    }
                    if (site.RegistrationPageId == page.Id)
                    {
                        site.RegistrationPageId = null;
                        site.RegistrationPageRouteId = null;
                    }
                }

                foreach (var pageView in pageViewService.GetByPageId(page.Id))
                {
                    pageView.Page = null;
                    pageView.PageId = null;
                }

                pageService.Delete( page );

                rockContext.SaveChanges();

                PageCache.Flush( page.Id );
            }

            BindPagesGrid();
        }