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POEF 4.1 POCO Accessing navigation properties after Db.Entry()
 

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    <h1>The Problem</h1> <p>Not sure what the right way to do this is... I have a simple class:</p> <pre><code>public partial class Event { public int Id { get; set; } public string Description { get; set; } public int? PreviousEventId { get; set; } public virtual Event PreviousEvent { get; set; } } </code></pre> <p>In my MVC 3 project, I have a form that is used to edit event description and (optionally) select a previous event from a drop down list. Form is submitted to an action and, as usual with MVC 3, automagically mapped to an <code>Event</code>:</p> <pre><code>[HttpPost] public ActionResult SaveEvent(Event myEvent) { if (ModelState.IsValid) { Db.Entry(myEvent).State = EntityState.Modified; // do some additional checks Db.SaveChanges(); } } </code></pre> <p>I'd like to do some additional validation that needs access to <code>PreviousEvent</code> before I save my entity. However, the navigation property is always <code>null</code> when I access it in the code above. This makes sense - the form is mapped directly to my POCO class, <code>Event</code>, and not to its proxy created by EF.</p> <h1>The Question</h1> <p>Is there any way to swap my modified <code>Event</code> for its proxy so that EF can help out with loading its navigation properties? I could do:</p> <pre><code>Db.Entry(myEvent).Reference(e =&gt; e.PreviousEvent).Load(); // do some checking on myEvent.PreviousEvent </code></pre> <p>...but loading all navigation properties this way seems mundane (there's a lot more to this class than shown), and I'm hoping EF has a better way of doing this. Does it indeed?</p>
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