<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:set="http://www.sitecore.net/xmlconfig/set/" xmlns:role="http://www.sitecore.net/xmlconfig/role/">
    <sitecore>
        <pipelines>
            <renderField>
                <processor
                  patch:before="*[@type='Sitecore.Pipelines.RenderField.GetLinkFieldValue, Sitecore.Kernel']"
                  type="Supernatural.Foundation.SitecoreExtensions.Pipelines.RenderPhoneLink, Supernatural.Foundation.SitecoreExtensions" />
            </renderField>
        </pipelines>
        <controlSources>
            <source
              mode="on"
              namespace="Supernatural.Foundation.SitecoreExtensions.Commands"
              assembly="Supernatural.Foundation.SitecoreExtensions"
              prefix="content" />
        </controlSources>
        <commands>
            <command name="webedit:edittelephonelink" type="Supernatural.Foundation.SitecoreExtensions.Commands.TelephoneEditLink, Supernatural.Foundation.SitecoreExtensions" />
        </commands>
    </sitecore>
</configuration>

<?xml version="1.0"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:role="http://www.sitecore.net/xmlconfig/role/"  xmlns:env="http://www.sitecore.net/xmlconfig/env/">
    <sitecore role:require="Standalone or ContentManagement">
        <unicorn>
            <configurations>
                <configuration name="Foundation.SitecoreExtensions.GeneralLink"
                            description="GeneralLink Core Database">
                    <targetDataStore physicalRootPath="$(sourceFolder)\$(layer)\$(module)\serialization\GeneralLink" />
                    <syncConfiguration type="Unicorn.Loader.DefaultSyncConfiguration, Unicorn" singleInstance="true" updateLinkDatabase="false" updateSearchIndex="true" maxConcurrency="1" />
                    <predicate
                      type="Unicorn.Predicates.SerializationPresetPredicate, Unicorn"
                      singleInstance="true">
                        <!-- Core Database -->
                        <include
                          name="General Link"
                          database="core"
                          path="/sitecore/system/Field types/Link Types/General Link" />
                    </predicate>
                </configuration>
            </configurations>
        </unicorn>
    </sitecore>
</configuration>

using System.Collections.Specialized;
using Sitecore;
using Sitecore.Diagnostics;
using Sitecore.Shell.Applications.ContentEditor;
using Sitecore.Text;
using Sitecore.Web.UI.Sheer;
namespace Supernatural.Foundation.SitecoreExtensions.Commands
{
    public class TelephoneLink : Link
    {
        public TelephoneLink()
        {
            Class = "scContentControl";
            Activation = true;
        }
        // Handles the message.
        public override void HandleMessage(Message message)
        {
            Assert.ArgumentNotNull(message, "message");
            base.HandleMessage(message); //base handles other message requests
            if (message["id"] != ID)
                return;
            switch (message.Name)
            {
                case "contentlink:telephonelink":
                    {
                        var url = new UrlString(UIUtil.GetUri("control:TelephoneLinkForm"));
                        Insert(url.ToString(), new NameValueCollection
                    {
                        {
                            "height",
                            "425"
                        }
                    });
                        break;
                    }
                default:
                    {
                        return;
                    }
            }
        }
    }
}

using Sitecore;
using Sitecore.Collections;
using Sitecore.Data;
using Sitecore.Data.Fields;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;
using Sitecore.Shell.Applications.ContentEditor;
using Sitecore.Shell.Applications.WebEdit.Commands;
using Sitecore.Shell.Framework.Commands;
using Sitecore.Sites;
using Sitecore.Text;
using Sitecore.Web;
using Sitecore.Web.UI;
using Sitecore.Web.UI.Sheer;
using Sitecore.Web.UI.WebControls;
using Sitecore.Xml.Xsl;
using System;
using System.Collections;
using System.Net;
using System.Text.RegularExpressions;
namespace EH.Foundation.SitecoreExtensions.Commands
{
    public class TelephoneEditLink : WebEditLinkCommand
    {
        protected static void Run(ClientPipelineArgs args)
        {
           
            else
            {
                XmlValue value = new XmlValue(args.Parameters["fieldValue"], "link");
                UrlString urlString = new UrlString(Context.Site.XmlControlPage);
                urlString["xmlcontrol"] = "SupernaturalGeneralLink";
            }
        }
       
    }
    }

using Sitecore;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;
using Sitecore.Links.UrlBuilders;
using Sitecore.Resources.Media;
using Sitecore.Shell.Applications.Dialogs;
using Sitecore.Shell.Framework;
using Sitecore.StringExtensions;
using Sitecore.Utils;
using Sitecore.Web;
using Sitecore.Web.UI;
using Sitecore.Web.UI.HtmlControls;
using Sitecore.Web.UI.Sheer;
using Sitecore.Web.UI.WebControls;
using Sitecore.Xml;
using System;
using System.Text.RegularExpressions;
// ============================================================================
// SupernaturalGeneralLinkForm
//
// Based on Sitecore 10.2 GeneralLinkForm.
//
// Customizations:
//   - Added Telephone ("tel") link type support
//   - Added LinkTelephone control
//   - Added GetTelephone()
//   - Added SetTelephoneLinkAttributes()
//   - Added SetTelephoneLinkControls()
//   - Added "tel" support in OnOK()
//   - Added "tel" support in SetModeSpecificControls()
// ============================================================================
namespace Supernatural.Foundation.SitecoreExtensions.Dialogs
{
    public class SupernaturalGeneralLinkForm : LinkForm
    {
        
        protected Edit LinkTelephone;
        /// <summary>Gets or sets CurrentMode.</summary>
        /// <value>The current mode.</value>
        private string CurrentMode
        {
          ///see original class
        }
        [ProcessorMethod]
        protected void OnModeChange(string mode)
        {
          ///see original class
        }
        protected override void OnOK(object sender, EventArgs args)
        {
           ///see original class
                ///Added part to the Switch statement
                case "tel":
                    flag = SetTelephoneLinkAttributes(packet);
                    break;
                    ///End
          ///see original class
        }
        private bool SetTelephoneLinkAttributes(Packet packet)
        {
            ///see original class
            
            ///Test if the phone number is valid. I did not use a regex as the other examples have. 
            ///See TryNormalizeTelephone Class later in the blog
            if (!SitecoreHelper.Helper.TryNormalizeTelephone(LinkTelephone.Value, out telephone))
            {
                SheerResponse.Alert("The telephone number is invalid.");
                return false;
            }
            ///see original class
        }
        private void SetTelephoneLinkControls()
        {
            if (LinkType == "tel" && string.IsNullOrEmpty(LinkTelephone.Value))
                LinkTelephone.Value = LinkAttributes["url"].Replace("tel:", "");
            ShowContainingRow(LinkTelephone);
            SectionHeader.Text =
                Translate.Text("Specify the Telephone, e.g. 800-555-1212");
        }
               
        /// <summary>The set mode specific controls.</summary>
        /// <exception cref="T:System.ArgumentException">
        /// </exception>
        private void SetModeSpecificControls()
        {
            ///see original class
            switch (this.CurrentMode)
            {
                ///Added to the Switch
                case "tel":
                    SetTelephoneLinkControls();
                    break;
                ///End Add
  
            }
              ///see original class
        }
        /// <summary>Updates the preview.</summary>
        /// <param name="item">The item.</param>
        private void UpdateMediaPreview(Item item)
        {
            ///see original class
        }
    }
    }

using System;
using System.Text.RegularExpressions;
using Sitecore;
using Sitecore.Diagnostics;
using Sitecore.Shell.Applications.Dialogs;
using Sitecore.Web.UI.HtmlControls;
using Sitecore.Web.UI.Sheer;
using Sitecore.Xml;
namespace Supernatural.Foundation.SitecoreExtensions.Dialogs
{
    public class TelephoneLinkForm : LinkForm
    {
        protected Edit Class;
        protected Edit Text;
        protected Edit Title;
        protected Edit Url;
        protected override void OnLoad(EventArgs e)
        {
            Assert.ArgumentNotNull(e, "e");
            base.OnLoad(e);
            if (Context.ClientPage.IsEvent)
            {
                return;
            }
            var item = LinkAttributes["url"];
            if (LinkType != "tel")
            {
                item = string.Empty;
            }
            Text.Value = LinkAttributes["text"];
            Url.Value = item.Replace("tel:", "");
            Class.Value = LinkAttributes["class"];
            Title.Value = LinkAttributes["title"];
        }
        protected override void OnOK(object sender, EventArgs args)
        {
            Assert.ArgumentNotNull(sender, "sender");
            Assert.ArgumentNotNull(args, "args");
            
            string telephone;
            ///More about the validation class later in the blog.
            if (!SitecoreHelper.Helper.TryNormalizeTelephone(Url.Value, out telephone))
            {
                SheerResponse.Alert("The telephone number is invalid.");
                return;
            }
            var packet = new Packet("link");
            SetAttribute(packet, "text", Text);
            SetAttribute(packet, "linktype", "tel");
            SetAttribute(packet, "url", telephone);
            SetAttribute(packet, "anchor", string.Empty);
            SetAttribute(packet, "title", Title);
            SetAttribute(packet, "class", Class);
            SheerResponse.SetDialogValue(packet.OuterXml);
            base.OnOK(sender, args);
        }
    }
}

using Sitecore.Data.Fields;
namespace Supernatural.Foundation.SitecoreExtensions.Models
{
    public class LinkInfo
    {
        public string Url { get; set; }
        public string Text { get; set; }
        public string Title { get; set; }
        public string Anchor { get; set; }
        public string Target { get; set; }
        public LinkInfo() { }
        public LinkInfo(LinkField item)
        {
            switch (item.LinkType)
            {
                case "tel":
                    Url = item.Url;
                    break;
                default:
                    Url = item.GetFriendlyUrl();
                    break;
            }
            Text = item.Text;
            Title = item.Title;
            Anchor = item.Anchor;
            Target = item.Target;
        }
    }
}

namespace Supernatural.Foundation.SitecoreExtensions.Pipelines
{
    public class RenderPhoneLink
    {
        public void Process(Sitecore.Pipelines.RenderField.RenderFieldArgs args)
        {
            if (args != null && (args.FieldTypeKey == "link" || args.FieldTypeKey == "general link"))
            {
                var field = args.Item.Fields[args.FieldName];
                if (field != null)
                {
                    var linkField = new Sitecore.Data.Fields.LinkField(field);
                    if (!string.IsNullOrEmpty(linkField.Url) && linkField.LinkType == "tel")
                    {
                        args.Parameters["href"] = linkField.Url;
                    }
                }
            }
        }
    }
}

<?xml version="1.0" encoding="utf-8" ?>
<control xmlns:def="Definition" xmlns="http://schemas.sitecore.net/Visual-Studio-Intellisense">
  <SupernaturalGeneralLink>
    <Stylesheet Src="/sitecore/shell/Applications/Dialogs/GeneralLink/GeneralLink.css"></Stylesheet>
    /sitecore/shell/Applications/Dialogs/GeneralLink/GeneralLink.js
    <FormDialog Icon="Network/32x32/link.png" Header="Insert a link"
      Text="Select the link type and specify the appropriate properties."
      OKButton="OK">
      <CodeBeside Type="Supernatural.Foundation.SitecoreExtensions.Dialogs.SupernaturalGeneralLinkForm, Supernatural.Foundation.SitecoreExtensions" />
  
      <GridPanel Height="100%" Width="100%" VAlign="top" Fixed="true" Columns="3">
      
          <!--Telepehone link-->
          <Border ID="Telephone">
            <a href="#" class="mode" onclick="javascript:return scForm.invoke('OnModeChange','tel')" onfocus="this.blur()">
              <ThemedImage Class="mode-icon" Src="/~/icon/office/32x32/smartphone.png" />
              <div class="mode-text">
                <Literal Text="Telephone Link"/>
              </div>
            </a>
          </Border>
          
        <!--Center column-->
        <Space GridPanel.Width="8px" />
        <!--Right column-->
        <Border Class="right-column" Height="100%" GridPanel.Width="100%" GridPanel.Height="100%">
        
              <Literal Text="Telephone Number:" GridPanel.NoWrap="true"/>
              <Edit Width="100%" Class="scQuirksBoxModel" GridPanel.Row.ID="LinkTelephoneRow" ID="LinkTelephone"/>
            
              <Edit Width="100%" Class="scQuirksBoxModel" GridPanel.Row.ID="QuerystringRow" ID="Querystring"/>
            </GridPanel>
          </GridPanel>
        </Border>
      </GridPanel>
      <Button Header="Upload" ID="UploadMedia" def:placeholder="Buttons" Click="UploadImage"/>
    </FormDialog>
  </SupernaturalGeneralLink>
</control>

<?xml version="1.0" encoding="utf-8"?>
<control xmlns:def="Definition"
         xmlns="http://schemas.sitecore.net/Visual-Studio-Intellisense">
  <TelephoneLinkForm>
    <FormDialog
      Icon="Network/32x32/mail.png"
      Header="Insert a telephone link"
      Text="Please specify the telephone number address and any additional properties. When done, click OK."
      OKButton="OK">
      <CodeBeside Type="Supernatural.Foundation.SitecoreExtensions.Dialogs.TelephoneLinkForm,Supernatural.Foundation.SitecoreExtensions" />
      <a id="telephone"></a>
      <GridPanel
        Class="scFormTable"
        CellPadding="2"
        Columns="2"
        Width="100%">
        <Label For="Text" GridPanel.NoWrap="true">
          <Literal Text="Link description:" />
        </Label>
        <Edit ID="Text"
              Width="100%"
              GridPanel.Width="100%" />
        <Label For="Url" GridPanel.NoWrap="true">
          <Literal Text="Telephone Number:" />
        </Label>
        <Edit ID="Url"
              Width="100%" />
        <Label For="Class" GridPanel.NoWrap="true">
          <Literal Text="Style class:" />
        </Label>
        <Edit ID="Class"
              Width="100%" />
        <Label For="Title" GridPanel.NoWrap="true">
          <Literal Text="Alternate text:" />
        </Label>
        <Edit ID="Title"
              Width="100%" />
      </GridPanel>
    </FormDialog>
  </TelephoneLinkForm>
</control>