GlassMapper: Unpublishable items are null in preview

Question

When an item is set to unpublishable, all methods to get the item for a rendering with GlassMapper return null.

public class PageHeaderController : GlassController
{
    public override ActionResult Header()
    {
        BaseItem model = SitecoreContext.GetCurrentItem<BasePage>(); // null
        model = GetLayoutItem<BasePage>(); // null
        model = SitecoreContext.GetItem<BasePage>(RenderingContext.Current.Rendering.DataSource); // null
        return View(model);
    }
}

How can we get the item in that case to be able to provide a publishing preview for editors for items that are set to be published in the future?

The problem occurs whether we use the "Never Publish" setting or set the version to unpublishable or even when the version is set to be published in the future.

The preview is really running with the master database.

Answer 1

This is normal behavior for the Preview feature. The purpose of this feature is to show you what the page will look like once published. Therefore the behavior you're encountering sort of makes sense, considering the page would simply not be published. To be fair, a more graceful approach (e.g. warning message) would be appreciated.

There are a couple of ways to get around it.

(1) If it's just for a one-off preview, you can change the preview URL like so. If Sitecore generates:

http://mysite.local/?sc_itemid=%7BFC3FE8C5-FAE6-4C67-8F21-B3757D143D4A%7D&sc_mode=preview&sc_lang=en-US&sc_site=mysite

Change it to:

http://mysite.local/?sc_itemid=%7BFC3FE8C5-FAE6-4C67-8F21-B3757D143D4A%7D&sc_mode=normal&sc_lang=en-US&sc_site=mysite&sc_database=master

Note the sc_mode and sc_database parameters.

(2) In code, you could disable site filtering by setting Sitecore.Context.Site.DisableFiltering to true. More details in this answer here: https://stackoverflow.com/a/20390596/1327412