Disable editing on rendering in pipeline

Question

I created a composite components control for Web Forms. I accomplished it by overriding the RenderLayout pipeline processor Sitecore.Pipelines.RenderLayout.InsertRenderings. The issue I have is that I want the renderings (sublayouts) editing be disabled. In the pipeline, the Editing property of the rendering item is "read only" at run time.

Does any know of a way to programmatically disable the editing ability of the renderings in my composite placeholder?

public class RenderLayout : RenderLayoutProcessor
{
    public override void Process(RenderLayoutArgs args)
    {
        Assert.ArgumentNotNull(args, "args");
        if (Context.Item == null)
        {
            return;
        }

        using (new ProfileSection("Insert renderings into page."))
        {
            InsertRenderingsArgs insertRenderingsArgs = new InsertRenderingsArgs();
            CorePipeline.Run("insertRenderings", insertRenderingsArgs);

            foreach (RenderingReference current in insertRenderingsArgs.Renderings)
            {
                current.RenderingItem.Editable = false; <----HERE
                Context.Page.AddRendering(current);
            }
        }
    }
}

Answer 1

Problem

The property doesn't easily let itself override. I was going to suggest forcing the value with reflection, but that won't work. The property is declared like this:

public virtual bool Editable
{
  get
  {
    return this.InnerItem["Editable"] == "1";
  }
}

Workaround

On the bright side, the RenderingItem class follows a well established CustomItem pattern, so a bit of code will go a long way. Declare a new class, NonEditableRenderingItem - like this:

public class NonEditableRenderingItem : RenderingItem
{
    public NonEditableRenderingItem(Item item) : base(item) {}

    public override bool Editable => false;
}

And then your loop like this. A slight bit of reflection necessary to compensate the shortcomings in Sitecore standard libraries ;-)

    foreach (RenderingReference current in insertRenderingsArgs.Renderings)
    {
        var neRenderingItem = new NonEditableRenderingItem(current.RenderingItem.InnerItem);
        current.GetType().GetField("renderingItem", BindingFlags.Instance | BindingFlags.NonPublic).SetValue(current, neRenderingItem);
        Context.Page.AddRendering(current);
    }

Disclaimer. I don't have a Webforms based solution up and running locally, nor the setup required to fully test your issue. But the above should work, in my opinion.