Carrotware.CMS.UI.Controls.ContentPageNext.OnPreRender C# (CSharp) Method

        protected override void OnPreRender(EventArgs e)
        {
            string sFieldValue = string.Empty;

            ContentPage cp = cu.GetContainerContentPage(this);
            SiteNav navNext = new SiteNav();
            if (NavigationDirection != NavDirection.Unknown) {
                using (ISiteNavHelper navHelper = SiteNavFactory.GetSiteNavHelper()) {
                    if (NavigationDirection == NavDirection.Prev) {
                        navNext = navHelper.GetPrevPost(SiteData.CurrentSiteID, cp.Root_ContentID, !SecurityData.IsAuthEditor);
                    }
                    if (NavigationDirection == NavDirection.Next) {
                        navNext = navHelper.GetNextPost(SiteData.CurrentSiteID, cp.Root_ContentID, !SecurityData.IsAuthEditor);
                    }

                    if (navNext != null) {
                        if (UseDefaultText) {
                            string sField = this.CaptionDataField.ToString();

                            object objData = ReflectionUtilities.GetPropertyValue(navNext, sField);
                            if (objData != null) {
                                sFieldValue = String.Format("{0}", objData);
                            }

                            this.Text = sFieldValue;
                        }

                        this.NavigateUrl = navNext.FileName;
                    } else {
                        this.Visible = false;
                    }
                }
            } else {
                this.Visible = false;
            }

            base.OnPreRender(e);
        }