We have begun using a great control called Pivotviewer. We see this as a control that can be used in many situations. http://www.silverlight.net/learn/pivotviewer/ - http://www.silverlight.net/learn/pivotviewer/

We use Silverlight DevForce, with a login manager, in a PRISM environment.

One of the challenges we encountered was that we had to develop some HttpHelpers that generate just-in-time collections to the Pivotviewer The Pivotviewer loads the collection from a .cxml file which is given by an url. The file does not exist in our case so the HttpHelper generates it on-the-fly and returns the collection. This code runs server side and so we had problems creating an Entity manager server side:

var m_entityManager = new C2NetDomainModelEntityManager();

Reason is that the login manager lacks credentials – a user is logged in client side thou.

Our workaround was to add some code to the login manager. We put the logged in userId in the Tag property on the default manager when a user logs in:

EntityManager.DefaultManager.Tag = user.p_userID; // so I can see how is logged in later.

On our server, when generating the collection, we use the default manager. But this does not give us our EntityModel – so we have to type cast everything:

var m_entityManager = EntityManager.DefaultManager;

var query = new EntityQuery<EntImage>()

                    .Include("p_imageAlbums")

                    .Include("p_imageAlbums.p_imageAlbumType");

query.QueryStrategy = new QueryStrategy(FetchStrategy.DataSourceOnly, MergeStrategy.OverwriteChanges);

var images = m_entityManager.ExecuteQuery<EntImage>(query);

And then we use the Tag property of the default manager to do some access management:

if (album.p_usersWithAccess.Where(user => user.p_userID == (string) m_entityManager.Tag).Count() > 0)

hasAccessToImage = true;

Is this the right way doing it, when working server side?

Or is there a better way?

Our HttpHandlers run in our webproject. They handle requests for any .cxml files.

When handling the request, we want to know you is logged in to the silverlight application, that is sending the request.

When handling the request, we need to run queries against our entitymodel to generate some data for the .cxml file.

When the user logs into to the silverlight application, I set:

EntityManager.DefaultManager.Tag = user;

, within the login manager.

When a request comes in, I create the manager this way:

var m_entityManager = EntityManager.DefaultManager;

And get the user this way:

var user = m_entityManager.Tag;

This is probably not good enough because I have NOT tested this:

User A logs in and requests HIS collection.

User B logs in and requests HIS collection.

User A makes another request to get HIS collection.

I am not sure about the ASP.Net security stuff – I will look into that.

Thanks DenisK & smi-mark,

I have some reading to do. But in the mean while I ended doing something like this and it works:

When making the request, I attach this to the url:

„MyCollection.cxml?user=“ + someUserId;

And when handling the request I do like this:

// create a entitymanager

var m_entityManager = new C2NetDomainModelEntityManager(EntityManager.DefaultManager);

// retrieve the user from the querystring

var userid = context.Query["user"];

// check if there is a user

if(string.IsNullOrEmpty(userid))

throw new Exception("No access!");

....

.....

..

Smi-mark,

Thank you so very much!!!

This is very helpful!!! J