SF_13.1, SF_13.2, SF_13.3, SF_14.0, SF_14.1, SF_14.2, SF_14.3 - https://www.progress.com/documentation/sitefinity-cms/for-developers-add-a-translation-to-a-localized-page

TranslateSplitPageSnippet2.cs

using System;
using System.Globalization;
using System.Linq;
using System.Text.RegularExpressions;
using Telerik.Sitefinity.Localization;
using Telerik.Sitefinity.Modules.Pages;
using Telerik.Sitefinity.Pages.Model;
using Telerik.Sitefinity.Services;

namespace Telerik.Sitefinity.Documentation.CodeSnippets.DevGuide.SitefinityEssentials.Multilingual
{
    public partial class MultilingualSnippets
    {
        public static void TranslateSplitPage(Guid pageNodeId, string targetCulture, string pageName, bool copyContents, string sourceCulture)
        {
            // Get the PageNode
            PageManager manager = PageManager.GetManager();
            PageNode pageNode = manager.GetPageNodes().FirstOrDefault(x => x.Id == pageNodeId);

            if (pageNode == null)
            {
                return; // PageNode not found
            }

            CultureInfo targetCultureInfo = SystemManager.CurrentContext.AppSettings.GetCultureByName(targetCulture);

            // Set values for PageNode properties
            pageNode.Title.SetString(targetCultureInfo, pageName);
            pageNode.Description.SetString(targetCultureInfo, pageName);
            pageNode.UrlName.SetString(targetCultureInfo, Regex.Replace(pageName.ToLower(), @"[^\w\-\!\$\'\(\)\=\@\d_]+", "-"));

            PageData pageData = null;

            if (pageNode.LocalizationStrategy != LocalizationStrategy.Split)
            {
                // Set the pageNode LocalizationStrategy for the first method call
                manager.InitializePageLocalizationStrategy(pageNode, LocalizationStrategy.Split, false);
            }
            else
            {
                // For subsequent method calls create an empty page data 
                pageData = manager.CreatePageData();
                pageData.Culture = targetCultureInfo.Name;
                pageData.NavigationNode = pageNode;
            }

            if (copyContents)
            {
                // Copy page contents from source culture
                CultureInfo sourceCultureInfo = SystemManager.CurrentContext.AppSettings.GetCultureByName(sourceCulture);
                manager.InitializeSplitPage(pageNode, sourceCultureInfo, targetCultureInfo);
            }

            // Retreive the page data of the page node
            pageData = pageNode.GetPageData(targetCultureInfo);

            // Set values for PageData properties
            pageData.HtmlTitle.SetString(targetCultureInfo, pageName);
            pageData.Description.SetString(targetCultureInfo, pageName);
            pageData.Keywords.SetString(targetCultureInfo, pageName);

            // Publish draft page
            var page = manager.EditPage(pageData.Id, targetCultureInfo);
            manager.PublishPageDraft(page, targetCultureInfo);
            // Publish the page 
            pageNode.ApprovalWorkflowState.SetString(targetCultureInfo, "Published");
            manager.SaveChanges();
        }
    }
}