Glass BeginEditFrame to edit children of a referenced DropLink field

Question

I am looking for some help in figuring out an appropriate approach to this setup.
I have a Sitecore tree that looks something like this:

• content
  • settings
  • home
    • potato
      • spud1
      • spud2

The settings node has a droplink field that points to the potato item. I have a POCO model that roughly looks like this:

[SitecoreType( AutoMap=true, TemplateId="1234..." )]
public class ModelA {
   public virtual Guid Id { get; set;}
   public virtual String Name { get; set; }
   public virtual ModelB Potato { get; set; }
}

[SitecoreType( AutoMap=true, TemplateId="1235..." )]
public class ModelB {
   public virtual Guid Id { get; set;}
   public virtual IEnumerable<Spud> Children { get; set; }
}

While the general rendering behaviour of this setup seems fine, we're having some issues trying to get an edit frame where we can add a new spud3 to the list of spuds.

The current setup has been centered around:

@using( BeginEditFrame( Model, "Title", m => m.Potato ) ) {}

but this isn't really doing what we want (haven't got exactly what it's not doing at hand as I'm posting on behalf of someone, but will update in 12hrs time with additional detail).

Assuming what we're trying to do is reasonable, can anyone spot the issue in the setup above?

We've also noticed a (probably known) bug where if the last 2 (supposedly optional) arguments of the BeginEditFrame() method are omitted a NullReferenceException is thrown from Sitecore's WebControl::GetItem().
[Note please @MikeEdwards if you're reading this ;)]

Answer 1

Can you change this to use datasources? If you did that then the rendering would point to potato as its datasource. You would add the Insert web edit button to your rendering's Experience Editor Buttons field.

If it isn't possible then try changing your edit frame code to pass in the insert button. You should create a custom folder under /sitecore/content/Applications/WebEdit/Edit Frame Buttons in core and duplicate the insert button into it (the insert button is located at /sitecore/content/Applications/WebEdit/Edit Frame Buttons/Default/Insert). Then you would pass in your datasource item and the button folder's id to the edit frame:

@using(Html.BeginEditFrame(Model.Potato.Id, {Your_Custom_Button_Folder}) ) {}