General Link (Insert media item) add custom property when click from Experience Editor

Question

We would like to add custom property when we click on General link from Experience Editor.

Would like to add custom property below "Alternate Text" and append custom property values in URL.

Answer 1

For adding a custom attribute to the media link you can follow the approach in this blog post https://sitecorejunkie.com/2015/10/10/add-a-custom-attribute-to-the-general-link-field-in-sitecore/, which describes the exact steps required for adding it for internal link and general links.

Based on your printscreen, if you would like to customize the media link dialog you have to change the custom form class and the dialog.

For the Sheer UI Custom form class you would need to look at the class Sitecore.Shell.Applications.Dialogs.MediaLink.MediaLinkForm from the dll Sitecore.Client.dll and have your custom one based on this. You would need to customize the Sheer UI dialog based on the \sitecore\shell\Applications\Dialogs\MediaLink\MediaLink.xml file instead.

Answer 2

1- Edit the file "...\sitecore\shell\Applications\Dialogs\MediaLink\MediaLink.xml"

2- Right below "alternate text", add:

<Literal Text="My text:" GridPanel.NoWrap="true"/>
          <Edit ID="MyText" Width="100%"/>
          

3- Comment out the line:

<CodeBeside Type="Sitecore.Shell.Applications.Dialogs.MediaLink.MediaLinkForm,Sitecore.Client"/>

and add

<CodeBeside Type="yournamespace.yourform,[yourassembly]"/>

4- Write your own class replacing the following, this time writing your property "MyText" and build your assembly (that you added above) and interpret it accordingly:

using System;
using System.Collections.Specialized;
using System.Web.UI.WebControls;```

namespace Sitecore.Shell.Applications.Dialogs.MediaLink
{
    /// <summary>
    /// Link of type media.
    /// </summary>
    public class MediaLinkForm : LinkForm
    {
        /// <summary>
        /// The anchor.
        /// </summary>
        protected Edit Anchor;

        /// <summary>
        /// The class.
        /// </summary>
        protected Edit Class;

        /// <summary>
        /// The custom label.
        /// </summary>
        protected Panel CustomLabel;

        /// <summary>
        /// The custom target.
        /// </summary>
        protected Edit CustomTarget;

        /// <summary>
        /// The media link data context.
        /// </summary>
        protected DataContext MediaLinkDataContext;

        /// <summary>
        /// The media link treeview.
        /// </summary>
        protected TreeviewEx MediaLinkTreeview;

        /// <summary>
        /// The preview.
        /// </summary>
        protected Border Preview;

        /// <summary>
        /// The target.
        /// </summary>
        protected Combobox Target;

        /// <summary>
        /// The text.
        /// </summary>
        protected Edit Text;

        /// <summary>
        /// The title.
        /// </summary>
        protected Edit Title;

        /// <summary> The upload button </summary>
        protected Button Upload;

        public MediaLinkForm()
        {
        }

        /// <summary>
        /// Handles the message.
        /// </summary>
        /// <param name="message">
        /// The message.
        /// </param>
        public override void HandleMessage(Message message)
        {
            Assert.ArgumentNotNull(message, "message");
            Item item = null;
            if (message.Arguments.Count > 0 && ID.IsID(message.Arguments["id"]))
            {
                IDataView dataView = this.MediaLinkTreeview.GetDataView();
                if (dataView != null)
                {
                    item = dataView.GetItem(message.Arguments["id"]);
                }
            }
            if (item == null)
            {
                item = this.MediaLinkTreeview.GetSelectionItem();
            }
            Dispatcher.Dispatch(message, item);
            base.HandleMessage(message);
        }

        /// <summary>
        /// Called when the listbox has changed.
        /// </summary>
        protected void OnListboxChanged()
        {
            if (this.Target.Value == "Custom")
            {
                this.CustomTarget.Disabled = false;
                this.CustomLabel.Disabled = false;
                return;
            }
            this.CustomTarget.Value = string.Empty;
            this.CustomTarget.Disabled = true;
            this.CustomLabel.Disabled = true;
        }

        /// <summary>
        /// Raises the load event.
        /// </summary>
        /// <param name="e">
        /// The <see cref="T:System.EventArgs" /> instance containing the event data.
        /// </param>
        /// <remarks>
        /// This method notifies the server control that it should perform actions common to each HTTP
        /// request for the page it is associated with, such as setting up a database query. At this
        /// stage in the page lifecycle, server controls in the hierarchy are created and initialized,
        /// view state is restored, and form controls reflect client-side data. Use the IsPostBack
        /// property to determine whether the page is being loaded in response to a client postback,
        /// or if it is being loaded and accessed for the first time.
        /// </remarks>
        protected override void OnLoad(EventArgs e)
        {
            string path;
            Assert.ArgumentNotNull(e, "e");
            base.OnLoad(e);
            if (Context.ClientPage.IsEvent)
            {
                return;
            }
            this.MediaLinkDataContext.GetFromQueryString();
            string item = base.LinkAttributes["target"];
            string empty = string.Empty;
            string linkTargetValue = LinkForm.GetLinkTargetValue(item);
            if (linkTargetValue == "Custom")
            {
                empty = item;
                this.CustomTarget.Disabled = false;
                this.CustomLabel.Disabled = false;
            }
            this.Text.Value = base.LinkAttributes["text"];
            this.Target.Value = linkTargetValue;
            this.CustomTarget.Value = empty;
            this.Class.Value = base.LinkAttributes["class"];
            this.Title.Value = base.LinkAttributes["title"];
            if (base.LinkType != "media")
            {
                path = "/sitecore/media library";
            }
            else
            {
                string str = base.LinkAttributes["id"];
                if (string.IsNullOrEmpty(str) || !ID.IsID(str))
                {
                    path = "/sitecore/media library";
                }
                else
                {
                    Item item1 = Client.ContentDatabase.GetItem(new ID(str));
                    if (item1 == null || !(item1.ID != ItemIDs.MediaLibraryRoot))
                    {
                        path = "/sitecore/media library";
                    }
                    else
                    {
                        path = item1.Paths.Path;
                        if (path.StartsWith("/sitecore/media library", StringComparison.InvariantCulture))
                        {
                            path = path.Substring("/sitecore/media library".Length);
                        }
                        if (this.MediaLinkTreeview.GetDataView() == null)
                        {
                            return;
                        }
                        if (item1.Parent != null)
                        {
                            this.MediaLinkDataContext.SetFolder(item1.Uri);
                        }
                    }
                }
            }
            this.MediaLinkDataContext.AddSelected(new DataUri(path));
            this.MediaLinkDataContext.Root = "/sitecore/media library";
            this.UpdatePreview(this.MediaLinkDataContext.GetFolder());
            this.Upload.ToolTip = Translate.Text("Upload a new media file to the Media Library");
        }

        /// <summary>
        /// Called when the new has folder.
        /// </summary>
        /// <param name="message">
        /// The message.
        /// </param>
        [HandleMessage("medialink:newfolder")]
        protected void OnNewFolder(Message message)
        {
            Assert.ArgumentNotNull(message, "message");
            Item folder = this.MediaLinkDataContext.GetFolder();
            if (folder != null)
            {
                Items.NewFolder(folder);
            }
        }

        /// <summary>
        /// Handles a click on the OK button.
        /// </summary>
        /// <param name="sender">
        /// </param>
        /// <param name="args">
        /// </param>
        /// <remarks>
        /// When the user clicks OK, the dialog is closed by calling
        /// the <see cref="M:Sitecore.Web.UI.Sheer.ClientResponse.CloseWindow">CloseWindow</see> method.
        /// </remarks>
        protected override void OnOK(object sender, EventArgs args)
        {
            Assert.ArgumentNotNull(sender, "sender");
            Assert.ArgumentNotNull(args, "args");
            Item selectionItem = this.MediaLinkTreeview.GetSelectionItem();
            if (selectionItem == null)
            {
                Context.ClientPage.ClientResponse.Alert("Select a media item.");
                return;
            }
            string mediaPath = selectionItem.Paths.MediaPath;
            string linkTargetAttributeFromValue = LinkForm.GetLinkTargetAttributeFromValue(this.Target.Value, this.CustomTarget.Value);
            Packet packet = new Packet("link", Array.Empty<string>());
            LinkForm.SetAttribute(packet, "text", this.Text);
            LinkForm.SetAttribute(packet, "linktype", "media");
            LinkForm.SetAttribute(packet, "title", this.Title);
            LinkForm.SetAttribute(packet, "class", this.Class);
            LinkForm.SetAttribute(packet, "target", linkTargetAttributeFromValue);
            LinkForm.SetAttribute(packet, "id", selectionItem.ID.ToString());
            SheerResponse.SetDialogValue(packet.OuterXml);
            base.OnOK(sender, args);
        }

        /// <summary>
        /// Called when this instance has open.
        /// </summary>
        protected void OnOpen()
        {
            Item selectionItem = this.MediaLinkTreeview.GetSelectionItem();
            if (selectionItem != null && selectionItem.HasChildren)
            {
                this.MediaLinkDataContext.SetFolder(selectionItem.Uri);
            }
        }

        /// <summary>
        /// Selects the tree node.
        /// </summary>
        protected void SelectTreeNode()
        {
            Item selectionItem = this.MediaLinkTreeview.GetSelectionItem();
            if (selectionItem == null)
            {
                return;
            }
            this.UpdatePreview(selectionItem);
        }

        /// <summary>
        /// Updates the preview.
        /// </summary>
        /// <param name="item">
        /// The item.
        /// </param>
        private void UpdatePreview(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            MediaUrlBuilderOptions thumbnailOptions = MediaUrlBuilderOptions.GetThumbnailOptions(item);
            thumbnailOptions.UseDefaultIcon = new bool?(true);
            thumbnailOptions.Width = new int?(96);
            thumbnailOptions.Height = new int?(96);
            thumbnailOptions.Language = item.Language;
            thumbnailOptions.AllowStretch = new bool?(false);
            string mediaUrl = MediaManager.GetMediaUrl(item, thumbnailOptions);
            this.Preview.InnerHtml = string.Concat("<img src=\"", mediaUrl, "\" width=\"96\" height=\"96\" border=\"0\" alt=\"\" />");
        }

        /// <summary>
        /// Uploads the image.
        /// </summary>
        protected void UploadImage()
        {
            Item selectionItem = this.MediaLinkTreeview.GetSelectionItem();
            if (selectionItem != null)
            {
                if (!selectionItem.Access.CanCreate())
                {
                    SheerResponse.Alert("You do not have permission to create a new item here.", Array.Empty<string>());
                    return;
                }
                Context.ClientPage.SendMessage(this, "media:upload(edit=1,load=1)");
            }
        }
    }
}