MongoDB Map class from nested elements in C#
<p>I've registered a class to pull addresses out of the a restaurants collection:</p>

<pre><code>BsonClassMap.RegisterClassMap&lt;RestaurantAddress&gt;(map =&gt;
{
    map.MapMember(c =&gt; c.Id).SetElementName(("_id"));
    map.MapMember(c =&gt; c.Building).SetElementName("address.building");
    map.MapMember(c =&gt; c.Street).SetElementName("address.street");
    map.MapMember(c =&gt; c.ZipCode).SetElementName("address.zipcode");
});
</code></pre>

<p>The Mongo document looks like:</p>

<pre><code>{
    "_id" : ObjectId("56bb82621ff72e0d9ba267cb"),
    "address" : {
        "building" : "6409",
        "coord" : [ 
            -74.005289, 
            40.628886
        ],
        "street" : "11 Avenue",
        "zipcode" : "11219"
    },
    "borough" : "Brooklyn",
    "cuisine" : "American ",
    "grades" : [ 
        {
            "date" : ISODate("2014-07-18T00:00:00.000Z"),
            "grade" : "A",
            "score" : 12
        }, 
        {
            "date" : ISODate("2013-07-30T00:00:00.000Z"),
            "grade" : "A",
            "score" : 12
        }
    ],
    "name" : "Regina Caterers",
    "restaurant_id" : "40356649"
}
</code></pre>

<p>When I get the document, the nested elements are all null though:</p>

<pre><code>[Test]
public void DeserializeToAddress()
{
    var collection = _database.GetCollection&lt;RestaurantAddress&gt;("grades");

    var address = collection.Find(a =&gt; a.Id == new ObjectId("56bb82621ff72e0d9ba267cb")).Limit(1).Single();

    Assert.That(address.Id, Is.Not.Null);
    Assert.That(address.Building, Is.Not.Null);
    Assert.That(address.Street, Is.Not.Null);
}
</code></pre>

<p>How should I be referencing nested elements?</p>

<p>The class to serialize into is:</p>

<pre><code>internal class RestaurantAddress
{
    public ObjectId Id { get; set; }
    public string Building { get; set; }
    public string Street { get; set; }
    public string ZipCode { get; set; }
    public Point CoordsPoint { get; set; }
}
</code></pre>

<p>Currenlty, I don't have anything for hyrating the <code>CoordsPoint</code> object.  That's for a later excercise.</p>