private void WriteExpandedNavigationProperty(
KeyValuePair <IEdmNavigationProperty, SelectExpandClause> navigationPropertyToExpand,
EntityInstanceContext entityInstanceContext,
ODataWriter writer)
{
Contract.Assert(entityInstanceContext != null);
Contract.Assert(writer != null);
IEdmNavigationProperty navigationProperty = navigationPropertyToExpand.Key;
SelectExpandClause selectExpandClause = navigationPropertyToExpand.Value;
object propertyValue = entityInstanceContext.GetPropertyValue(navigationProperty.Name);
if (propertyValue != null)
{
// create the serializer context for the expanded item.
ODataSerializerContext nestedWriteContext = new ODataSerializerContext(entityInstanceContext, selectExpandClause, navigationProperty);
// write object.
ODataEdmTypeSerializer serializer = SerializerProvider.GetEdmTypeSerializer(navigationProperty.Type);
if (serializer == null)
{
throw new SerializationException(
Error.Format(SRResources.TypeCannotBeSerialized, navigationProperty.Type.ToTraceString(), typeof(ODataMediaTypeFormatter).Name));
}
serializer.WriteObjectInline(propertyValue, navigationProperty.Type, writer, nestedWriteContext);
}
}
private void WriteFeed(IEnumerable enumerable, IEdmTypeReference feedType, ODataWriter writer,
ODataSerializerContext writeContext)
{
Contract.Assert(writer != null);
Contract.Assert(writeContext != null);
Contract.Assert(enumerable != null);
Contract.Assert(feedType != null);
IEdmEntityTypeReference elementType = GetEntityType(feedType);
ODataFeed feed = CreateODataFeed(enumerable, feedType.AsCollection(), writeContext);
if (feed == null)
{
throw new SerializationException(Error.Format(SRResources.CannotSerializerNull, Feed));
}
ODataEdmTypeSerializer entrySerializer = SerializerProvider.GetEdmTypeSerializer(elementType);
if (entrySerializer == null)
{
throw new SerializationException(
Error.Format(SRResources.TypeCannotBeSerialized, elementType.FullName(), typeof(ODataMediaTypeFormatter).Name));
}
// save this for later to support JSON lite streaming.
Uri nextPageLink = feed.NextPageLink;
feed.NextPageLink = null;
writer.WriteStart(feed);
foreach (object entry in enumerable)
{
if (entry == null)
{
throw new SerializationException(SRResources.NullElementInCollection);
}
entrySerializer.WriteObjectInline(entry, elementType, writer, writeContext);
}
// Subtle and suprising behavior: If the NextPageLink property is set before calling WriteStart(feed),
// the next page link will be written early in a manner not compatible with streaming=true. Instead, if
// the next page link is not set when calling WriteStart(feed) but is instead set later on that feed
// object before calling WriteEnd(), the next page link will be written at the end, as required for
// streaming=true support.
if (nextPageLink != null)
{
feed.NextPageLink = nextPageLink;
}
writer.WriteEnd();
}
private void WriteExpandedNavigationProperty(
KeyValuePair <IEdmNavigationProperty, SelectExpandClause> navigationPropertyToExpand,
EntityInstanceContext entityInstanceContext,
ODataWriter writer)
{
Contract.Assert(entityInstanceContext != null);
Contract.Assert(writer != null);
IEdmNavigationProperty navigationProperty = navigationPropertyToExpand.Key;
SelectExpandClause selectExpandClause = navigationPropertyToExpand.Value;
object propertyValue = entityInstanceContext.GetPropertyValue(navigationProperty.Name);
if (propertyValue == null)
{
if (navigationProperty.Type.IsCollection())
{
// A navigation property whose Type attribute specifies a collection, the collection always exists,
// it may just be empty.
// If a collection of entities can be related, it is represented as a JSON array. An empty
// collection of entities (one that contains no entities) is represented as an empty JSON array.
writer.WriteStart(new ODataFeed());
}
else
{
// If at most one entity can be related, the value is null if no entity is currently related.
writer.WriteStart(entry: null);
}
writer.WriteEnd();
}
else
{
// create the serializer context for the expanded item.
ODataSerializerContext nestedWriteContext = new ODataSerializerContext(entityInstanceContext, selectExpandClause, navigationProperty);
// write object.
ODataEdmTypeSerializer serializer = SerializerProvider.GetEdmTypeSerializer(navigationProperty.Type);
if (serializer == null)
{
throw new SerializationException(
Error.Format(SRResources.TypeCannotBeSerialized, navigationProperty.Type.ToTraceString(), typeof(ODataMediaTypeFormatter).Name));
}
serializer.WriteObjectInline(propertyValue, navigationProperty.Type, writer, nestedWriteContext);
}
}