I am still trying to find a good solution, but for now I have this code

private GuidUdi GetUdi(int id)
{
    var node = ApplicationContext.Services.ContentService.GetById(id);
            return node?.GetUdi();
 }

Hi Enrico,

I would urge you not to use contentservice for retreiving data. The content service hits the database and bypasses the memory cache. This can be performance issue

Dave

Thanks Dave,

I will give it a try

This new Udi property is giving me headache.

Do you know if it's possible modify the way the Rich Text Editor inserts links?

I tried with https://our.umbraco.org/documentation/implementation/Rest-Api/

But a lot of feature are missing. So I started to write my own Implementation.

This is the code of my controller

public class MyContentController : UmbracoApiController
    {
        private readonly IExtendedContentService _content;

        public MyContentController() : this(new ExtendedContentService())
        {
        }

        public MyContentController(IExtendedContentService content)
        {
            this._content = content;
        }

        /// <summary>
        ///     Return a tree structure of the pages of the website
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public HttpResponseMessage GetNavigationTree()
        {
            HttpResponseMessage response;

            var menuItems = _content.GetNavigationTree();

            if (menuItems == null)
            {
                response = Request.CreateResponse(HttpStatusCode.NotFound);
            }
            else
            {
                response = Request.CreateResponse(HttpStatusCode.OK, menuItems, new AngularJsonMediaTypeFormatter());
            }

            response.Headers.Add("Access-Control-Allow-Origin", "*");
            return response;
        }

        /// <summary>
        ///     Return a simple list of web pages
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public HttpResponseMessage GetNavigation()
        {
            HttpResponseMessage response;

            var linkItems = _content.GetNavigationList();

            if (linkItems == null)
            {
                response = Request.CreateResponse(HttpStatusCode.NotFound);

            }
            else
            {
                response = Request.CreateResponse(HttpStatusCode.OK, linkItems, new AngularJsonMediaTypeFormatter());
            }

            response.Headers.Add("Access-Control-Allow-Origin", "*");
            return response;
        }

        /// <summary>
        ///     Returns a node or page of the website
        /// </summary>
        /// <param name="id"></param>
        /// <param name="contentRequest"></param>
        /// <returns></returns>
        [HttpPost]
        public HttpResponseMessage GetNode([FromUri] int id, [FromBody] ContentRequest contentRequest)
        {
            HttpResponseMessage response;

            var node = _content.GetNode(id, contentRequest);

            if (node == null)
            {
                response = Request.CreateResponse(HttpStatusCode.NotFound);
            }
            else
            {
                response = Request.CreateResponse(HttpStatusCode.OK, node, new AngularJsonMediaTypeFormatter());
            }

            response.Headers.Add("Access-Control-Allow-Origin", "*");
            response.Headers.Add("Access-Control-Allow-Headers", "*");
            response.Headers.Add("Access-Control-Allow-Methods", "*");
            return response;
        }
    }

This is the code of my ExtendedContentService

 public class ExtendedContentService : UmbracoApiControllerBase, IExtendedContentService
    {
        /// <summary>
        ///     Return a simple list of web pages
        /// </summary>
        /// <returns></returns>
        public List<LinkItem> GetNavigationList()
        {
            var linkItems = new List<LinkItem>();
            var homepage = Umbraco.ContentAtRoot().First();

            linkItems.Add(new LinkItem
            {
                Id = homepage.Id,
                Name = homepage.Name,
                ParentId = 0,
                Url = homepage.Url,
                NodeUdi = GetUdi(homepage.Id).ToString()
            });

            foreach (var item in homepage.Children.Where("Visible"))
            {
                linkItems.AddRange(GetChildLinks(item));
            }

            return linkItems;
        }

        /// <summary>
        ///     Return a tree structure of the pages of the website
        /// </summary>
        /// <returns></returns>
        public List<MenuItem> GetNavigationTree()
        {
            var menuItems = new List<MenuItem>();
            var homepage = Umbraco.ContentAtRoot().First();

            // menuItems.Add(new MenuItem { name = homepage.Name, link = homepage.id,  url = homepage.Url, subtree = null});

            foreach (var item in homepage.Children.Where("Visible"))
            {
                menuItems.AddRange(GetTreeLinks(item));
            }

            return menuItems;
        }

        /// <summary>
        ///     Returns a node or page of the website
        /// </summary>
        /// <param name="id"></param>
        /// <param name="contentRequest"></param>
        /// <returns></returns>
        public IContent GetNode(int id, ContentRequest contentRequest)
        {
            if (id > 0)
            {
                var node = ApplicationContext.Services.ContentService.GetById(id);

                if (!string.IsNullOrEmpty(contentRequest.BaseUrl))
                {
                    foreach (var prop in node.Properties)
                    {
                        prop.Value = ReplaceImages(prop.Value, contentRequest.BaseUrl);
                        prop.Value = ReplaceLinks(prop.Value, contentRequest.HrefAttribute);
                    }
                }

                return node;
            }

            return null;
        }

        /// <summary>
        ///     Recursive function to create a simple list structure
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        private List<LinkItem> GetChildLinks(dynamic item)
        {
            var newItems = new List<LinkItem>();

            newItems.Add(new LinkItem
            {
                Id = item.Id,
                Name = item.Name,
                ParentId = item.ParentId,
                Url = item.Url,
                NodeUdi = GetUdi(item.Id).ToString()
            });


            foreach (var sub in item.Children.Where("Visible"))
            {
                newItems.AddRange(GetChildLinks(sub));
            }

            return newItems;
        }

        /// <summary>
        ///     Get Umbraco UDI code
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        private GuidUdi GetUdi(int id)
        {
            var node = ApplicationContext.Services.ContentService.GetById(id);
            return node?.GetUdi();
        }

        /// <summary>
        ///     Recursive function to create tree structure of the website pages
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        private List<MenuItem> GetTreeLinks(dynamic item)
        {
            var newItems = new List<MenuItem>();
            var tempItems = new List<MenuItem>();

            foreach (var sub in item.Children.Where("Visible"))
            {
                tempItems.AddRange(GetTreeLinks(sub));
            }

            newItems.Add(new MenuItem
            {
                name = item.Name,
                link = tempItems.Any() ? "#" : item.id.ToString(),
                url = item.Url,
                subtree = tempItems.Any() ? tempItems : null
            });

            return newItems;
        }

        /// <summary>
        ///     Replace Umbraco Media Images
        /// </summary>
        /// <param name="value"></param>
        /// <param name="baseUrl"></param>
        /// <returns></returns>
        private object ReplaceImages(object value, string baseUrl)
        {
            if (value != null)
            {
                var tempReplace = RemoveUdi(value.ToString());

                Regex removeId = new Regex("id=\"([^\"]*)\"", RegexOptions.IgnoreCase | RegexOptions.Singleline);
                tempReplace = removeId.Replace(tempReplace, "");

                Regex replaceImage = new Regex("/media/([^\"]*)", RegexOptions.IgnoreCase | RegexOptions.Singleline);
                tempReplace = replaceImage.Replace(tempReplace, baseUrl + "${0}");

                return (object) tempReplace;
            }

            return null;
        }

        /// <summary>
        ///     Remove Umbraco Udi code
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        private static string RemoveUdi(string value)
        {
            if (!string.IsNullOrEmpty(value))
            {
                Regex regexUdi = new Regex("data-udi=\"([^\"]*)\"", RegexOptions.IgnoreCase | RegexOptions.Singleline);

                return regexUdi.Replace(value, "");
            }

            return null;
        }

        /// <summary>
        ///     Replace Umbraco links
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        private object ReplaceLinks(object value, string hrefAttribute = "")
        {
            if (value != null)
            {

                string output = RemoveUdi(value.ToString());
                var links = GetNavigationList();

                string exp = "<a.*?href=[\"']/{localLink:(?<url>.*?)}[\"'].*?>";
                Regex regexp = new Regex(exp,
                    RegexOptions.IgnoreCase | RegexOptions.Compiled | RegexOptions.Singleline);

                if (links != null)
                {
                    for (Match match = regexp.Match(value.ToString()); match.Success; match = match.NextMatch())
                    {
                        for (int i = 0; i < links.Count; i++)
                        {

                            if (match.Groups[1].Value.IndexOf(links[i].NodeUdi, StringComparison.CurrentCultureIgnoreCase) > -1)
                            {
                                if (string.IsNullOrEmpty(hrefAttribute))
                                {
                                    output = output.Replace(match.ToString(), "<a href=\"" + links[i].Url + "\">");
                                }
                                else
                                {
                                    output = output.Replace(match.ToString(), "<a href=\"#!" + links[i].Url + "\">");
                                }


                            }
                        }
                    }
                }

                return (object) output;
            }

            return null;
        }
    }

This is the best solution I got at the moment. It's not perfect because scraping html strings to replace udi with absoulte path is not that easy.

Thanks Dave.

I will have a try and I let you know