public override void Process(IODataRequestMessage requestMessage, IODataResponseMessage responseMessage)
{
// TODO: we will need to add server-driven paging for delta link
object queryResults = this.QueryContext.ResolveQuery(this.DataSource);
using (var messageWriter = this.CreateMessageWriter(responseMessage))
{
IEdmNavigationSource navigationSource = this.QueryContext.Target.NavigationSource;
IEnumerable iEnumerableResults = queryResults as IEnumerable;
if (this.QueryContext.Target.NavigationSource != null && this.QueryContext.Target.TypeKind == EdmTypeKind.Collection)
{
IEdmEntitySetBase entitySet = navigationSource as IEdmEntitySetBase;
IEdmEntityType entityType = this.QueryContext.Target.ElementType as IEdmEntityType;
if (entitySet == null || entityType == null)
{
throw new InvalidOperationException("Invalid target when query feed.");
}
GenerateDeltaItemsFromFeed(iEnumerableResults, entitySet, ODataVersion.V4, this.QueryContext.QuerySelectExpandClause);
Uri newDeltaLink = null;
if (this.PreferenceContext.TrackingChanges)
{
var newDeltaToken = DeltaContext.GenerateDeltaToken(this.QueryContext.QueryUri, iEnumerableResults, entitySet, this.QueryContext.QuerySelectExpandClause);
newDeltaLink = new Uri(string.Format("{0}?{1}={2}", this.ServiceRootUri, ServiceConstants.QueryOption_Delta, newDeltaToken));
responseMessage.AddPreferenceApplied(ServiceConstants.Preference_TrackChanging);
}
ODataDeltaWriter resultWriter = messageWriter.CreateODataDeltaWriter(entitySet, entityType);
ResponseWriter.WriteDeltaFeed(resultWriter, this.DeltaItems, this.QueryContext.CountOption, newDeltaLink);
resultWriter.Flush();
}
else
{
throw Utility.BuildException(HttpStatusCode.Gone);
}
}
}
