Sitecore 8 throwing null exception when Datasource item does not exist

Question

I am facing the below problem and can't find out how to get around to it.

1. I have a rendering and its datasource is pointing to an item in the tree.
2. I publish the rendering but I don't publish the referenced item.
3. While viewing the page I get an error. [attached is the screen shot of the error i am getting]

I am using glass mapper.

Thanks in advance for your help.

Answer 1

To elaborate jammykam's answer, you can do something like the code below which I have found in this blog

Config Patch:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <pipelines>
      <mvc .getrenderer="">
        <processor patch:instead="processor[@type='Sitecore.Mvc.Pipelines.Response.GetRenderer.GetViewRenderer, Sitecore.Mvc']" type="Namespace.To.Sitecore.Pipelines.Response.GetRenderer.GetViewRendererWithItemValidation, Library">
        </processor>
      </mvc>
    </pipelines>
  </sitecore>
</configuration>

Code:

public class GetViewRendererWithItemValidation : GetViewRenderer
{        `
    protected override Renderer GetRenderer(Rendering rendering, GetRendererArgs args)
    {           
        var viewRenderer = base.GetRenderer(rendering, args) as ViewRenderer;
        if (viewRenderer == null)
            return null;

        // Ignore item check when in page editor
        // Also this will break if the item for the datasource has been deleted without removing the link.
        if (Context.PageMode.IsPageEditor || Context.PageMode.IsPageEditorEditing)
            return viewRenderer;

        // Override renderer to null when there is an unpublished item refererenced by underlying view
        return viewRenderer.Rendering.Item != null && viewRenderer.Rendering.RenderingItem.InnerItem != null
            ? viewRenderer
            : null;
    }
}