DynamicDataStoreTempDataProvider.cs

/// <summary>
/// Implementation that stores MVC TempData in DDS instead of through session
/// </summary>
class DynamicDataStoreTempDataProvider : ITempDataProvider
{
	private readonly ILog _logManager;

	public DynamicDataStoreTempDataProvider()
	{
		this._logManager = LogManager.GetLogger(typeof(DynamicDataStoreTempDataProvider));
	}

	private Guid GetUserId(HttpContextBase context)
	{
		//Get Anonymous ID if user isn't authenticated
		if (!context.User.Identity.IsAuthenticated)
		{
			if (AnonymousIdentificationModule.Enabled)
				return new Guid(context.Request.AnonymousID);
			else
				return Guid.NewGuid();
		}

		//Get the current users membership
		MembershipUser membership = Membership.GetUser();

		if (membership == null)
			return Guid.NewGuid();

		Guid guid;

		if (membership.ProviderUserKey == null)
			return Guid.NewGuid();

		//Let's check if its a guid we can use
		if (Guid.TryParse(membership.ProviderUserKey.ToString(), out guid))
			return guid;
	
		//Get a Guid if it is a int
		if (membership.ProviderUserKey is Int32)
		{
			byte[] bytes = new byte[16];
			
			int userId = (int) membership.ProviderUserKey;

			BitConverter.GetBytes(userId).CopyTo(bytes, 0);
			Guid membershipUserGuid = new Guid(bytes);
			return membershipUserGuid;
		}

		return Guid.NewGuid();
	}

	public void SaveTempData(ControllerContext controllerContext, IDictionary<string, object> values)
	{
		Guid userId = this.GetUserId(controllerContext.HttpContext);

		if (values == null || values.Count == 0)
		{
			TempDataStoreItem tempDataStoreItem = this.GetStoreItem(userId);
			
			//Remove the item from our store
			if (tempDataStoreItem != null)
				this.RemoveStoreItem(userId);
			
			return;
		}

		BinaryFormatter bf = new BinaryFormatter();
		
		using (MemoryStream ms = new MemoryStream())
		{
			try
			{
				//Serialize our data to store
				bf.Serialize(ms, values);
				byte[] raw = ms.ToArray();

				TempDataStoreItem tempDataStoreItem = new TempDataStoreItem();
				tempDataStoreItem.Id = Identity.NewIdentity(userId);
				tempDataStoreItem.RawTempData = raw;

				//Save it
				this.SaveStoreItem(tempDataStoreItem);
			}
			catch (SerializationException e)
			{
				this._logManager.Error("Failed to serialize values for TempData", e);
			}

		}
	}

	public IDictionary<string, object> LoadTempData(ControllerContext controllerContext)
	{
		Guid userId = this.GetUserId(controllerContext.HttpContext);

		//Get item for user
		TempDataStoreItem tempDataStoreItem = this.GetStoreItem(userId);

		if (tempDataStoreItem != null)
			this.RemoveStoreItem(userId);
		
		if (tempDataStoreItem == null || tempDataStoreItem.RawTempData == null)
			return null;
		
		BinaryFormatter bf = new BinaryFormatter();
		
		using (MemoryStream ms = new MemoryStream(tempDataStoreItem.RawTempData))
		{
			try
			{
				//Deserialize
				Dictionary<string, object> rawValues = bf.Deserialize(ms) as Dictionary<string, object>;
				return rawValues;
			}
			catch (SerializationException e)
			{
				this._logManager.Error("Failed to deserialize values for TempData", e);
				return null;
			}
		}
	}

	private TempDataStoreItem GetStoreItem(Guid userId)
	{
		using (DynamicDataStore store = DynamicDataStoreFactory.Instance.GetStore(typeof(TempDataStoreItem)) ?? DynamicDataStoreFactory.Instance.CreateStore(typeof(TempDataStoreItem)))
		{
			if (store == null)
				throw new InvalidOperationException("could not get datastore for tempDataStoreItem");

			TempDataStoreItem tempDataStoreItem = store.Load<TempDataStoreItem>(Identity.NewIdentity(userId));
			return tempDataStoreItem;
		}
	}

	public void RemoveStoreItem(Guid userId)
	{
		using (DynamicDataStore store = DynamicDataStoreFactory.Instance.GetStore(typeof(TempDataStoreItem)) ?? DynamicDataStoreFactory.Instance.CreateStore(typeof(TempDataStoreItem)))
		{
			if (store == null)
				throw new InvalidOperationException("Could not get datastore for TempDataStoreItem");

			store.Delete(Identity.NewIdentity(userId));
		}
	}

	public TempDataStoreItem SaveStoreItem(TempDataStoreItem tempDataStoreItem)
	{
		if (tempDataStoreItem == null)
			throw new ArgumentNullException("tempDataStoreItem");

		using (DynamicDataStore store = DynamicDataStoreFactory.Instance.GetStore(typeof(TempDataStoreItem)) ?? DynamicDataStoreFactory.Instance.CreateStore(typeof(TempDataStoreItem)))
		{
			if (store == null)
				throw new InvalidOperationException("Could not get datastore for TempDataStoreItem");

			store.Save(tempDataStoreItem);
		}

		return tempDataStoreItem;
	}
}

[EPiServerDataStore(AutomaticallyCreateStore = true, AutomaticallyRemapStore = true, StoreName = "TempData.DynamicDataStoreTempDataProvider")]
class TempDataStoreItem : IDynamicData
{
	public Identity Id { get; set; }
	public byte[] RawTempData { get; set; }
}