Hello everyone,

I am currently trying to make changes during the "ContentSavingNotification" event.

This is working so far.

I have a Multi Node Tree Picker and a Tags Property in my Document Type.

When I change something in the MNTP, the names of the selected nodes should automatically be saved in the tags property in the correct language.

This also works. But my problem is, when I select a node in the MNTP, save/publish and then navigate to another page, I get the message that there are unsaved changes. If I discard them and navigate to another page anyway and go back, the changes are apparently all saved.

If I save/publish the page twice, I don't get the message.

What could be the reason for this? Do I somehow need to say that the tags property is "dirty" or something?

Here is my handler (just code for testing): "tags" is my MNTP, umbTags is the actual "Tags" property

public class MultiLanguageTagHandler(
    ILocalizationService localizationService,
    IUmbracoContextAccessor umbracoContextAccessor) : INotificationHandler<ContentSavingNotification>
{
    public void Handle(ContentSavingNotification notification)
    {
        foreach (IContent content in notification.SavedEntities)
        {
            foreach (string language in content.AvailableCultures)
            {
                IUmbracoContext umbracoContext = umbracoContextAccessor.GetRequiredUmbracoContext();

                if (content.HasProperty("tags") && content.GetValue("tags", language) is string nodeIds)
                {
                    IEnumerable<string?> tags = nodeIds
                        .Split(',')
                        .Select(x => umbracoContext.Content!.GetById(UdiParser.Parse(x))?.Name(language))
                        .Where(x => !string.IsNullOrWhiteSpace(x));

                    if (tags.Count() != nodeIds.Split(',').Length)
                    {
                        notification.Messages.Add(new EventMessage("Error while saving",
                            "Some tags have not been published in the given culture.", EventMessageType.Error));

                        notification.Cancel = true;

                        continue;
                    }

                    content.SetValue("umbTags", string.Join(",", tags), language);
                }
            }
        }
    }
}