static public DataServiceState Save(DataServiceContext context, Dictionary <string, object> collections)
{
List <Type> knownTypes = GetKnownTypes(context);
Dictionary <EntityDescriptor, Guid> entityDescriptorToId;
ContextState contextState = context.SaveState(out entityDescriptorToId);
string contextAsString = SerializeContextToString(contextState, knownTypes);
var collectionsState = new Dictionary <string, CollectionState>();
if (collections != null)
{
foreach (KeyValuePair <string, object> kvp in collections)
{
IDataServiceCollection collection = (IDataServiceCollection)kvp.Value;
CollectionState collectionState = collection.SaveState(context, entityDescriptorToId);
collectionsState.Add(kvp.Key, collectionState);
}
}
DataServiceState state = new DataServiceState()
{
CollectionsState = collectionsState,
ContextAsString = contextAsString,
ContextTypeName = context.GetType().AssemblyQualifiedName,
KnownTypeNames = knownTypes.Select(t => t.AssemblyQualifiedName).ToList()
};
return(state);
}
CollectionState IDataServiceCollection.SaveState(
DataServiceContext context, Dictionary <EntityDescriptor, Guid> entityDescriptorToId)
{
if (this.observer == null)
{
throw new InvalidOperationException(Strings.DataServiceCollection_OperationForTrackedOnly);
}
if (this.observer.Context != context)
{
throw new InvalidOperationException(Strings.DataServiceState_CollectionNotInContext);
}
var state = new CollectionState();
state.EntitySetName = this.entitySetName;
state.EntityTypeName = typeof(T).AssemblyQualifiedName;
state.RootCollection = this.rootCollection;
state.DescriptorIds = new List <Guid>(this.Count);
foreach (object entity in this)
{
EntityDescriptor entityDescriptor = context.GetEntityDescriptor(entity);
Guid id = entityDescriptorToId[entityDescriptor];
state.DescriptorIds.Add(id);
}
return(state);
}
internal static DataServiceCollection <T> RestoreState(
CollectionState state, DataServiceContext context, Dictionary <Guid, EntityDescriptor> idToEntityDescriptor)
{
var items = new List <T>(state.DescriptorIds.Count);
foreach (Guid id in state.DescriptorIds)
{
EntityDescriptor entityDescriptor = idToEntityDescriptor[id];
items.Add((T)entityDescriptor.Entity);
}
DataServiceCollection <T> collection = new DataServiceCollection <T>(
context, items, TrackingMode.AutoChangeTracking, state.EntitySetName, null, null);
collection.rootCollection = state.RootCollection;
return(collection);
}
Dictionary <string, object> RestoreCollections(DataServiceContext context, Dictionary <Guid, EntityDescriptor> idToEntityDescriptor)
{
var collections = new Dictionary <string, object>(this.CollectionsState.Count);
foreach (KeyValuePair <string, CollectionState> kvp in this.CollectionsState)
{
CollectionState collectionState = kvp.Value;
Type entityType = Type.GetType(collectionState.EntityTypeName);
Type collectionType = typeof(DataServiceCollection <>).MakeGenericType(new Type[] { entityType });
MethodInfo restoreMethod = collectionType.GetMethod(
"RestoreState", BindingFlags.NonPublic | BindingFlags.Static);
Debug.Assert(restoreMethod != null);
object collection = restoreMethod.Invoke(null, new object[] { collectionState, context, idToEntityDescriptor });
collections.Add(kvp.Key, collection);
}
return(collections);
}
