/// <summary>
/// Replace the inner HTTP response stream with substituteStream using reflection.
///
/// The stream needs to be substituted because the request body needs to be translated before passed on to the base deserialization classes
/// to take advantage of OData V4 model validation. Unfortunately, although it is guaranteed to exist, the message field is marked private
/// in the ODataMessageWriter, so reflection must be used to modify it.
/// </summary>
/// <param name="writer">ODataMessageWriter which has not written yet.</param>
/// <param name="substituteStream">Replacement stream.</param>
/// <returns>The created stream.</returns>
public static Stream SubstituteResponseStream(this ODataMessageWriter writer, Stream substituteStream)
{
FieldInfo messageField = writer.GetType().GetField("message", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
object message = messageField.GetValue(writer);
// Throw an exception if the message field does not exist in ODataMessageReader class anymore.
if (message == null)
{
throw new Exception("The response body cannot be translated because the 'message' field does not exist in ODataMessageReader.");
}
FieldInfo requestMessageField = message.GetType().GetField("responseMessage", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
var responseMessage = requestMessageField.GetValue(message) as ODataMigrationMessageWrapper;
// Throw an exception if the responseMessage field does not exist in ODataRequestMessage class anymore.
if (responseMessage == null)
{
throw new Exception("The response body cannot be translated because the 'responseMessage' field does not exist in ODataResponseMessage or it cannot be cast to ODataMigrationMessageWrapper.");
}
Stream originalStream = responseMessage.Stream;
responseMessage.Stream = substituteStream;
return(originalStream);
}
/// <summary>
/// Replace the inner HTTP response stream with substituteStream using reflection.
///
/// The stream needs to be substituted because the request body needs to be translated before passed on to the base deserialization classes
/// to take advantage of OData V4 model validation. Unfortunately, although it is guaranteed to exist, the stream is marked private
/// in the ODataMessageReader, so reflection must be used to modify it.
/// </summary>
/// <param name="writer">ODataMessageWriter which has not written yet.</param>
/// <param name="substituteStream">Replacement stream.</param>
public static Stream SubstituteResponseStream(this ODataMessageWriter writer, Stream substituteStream)
{
FieldInfo messageField = writer.GetType().GetField("message", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
object message = messageField.GetValue(writer);
FieldInfo requestMessageField = message.GetType().GetField("responseMessage", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
object requestMessage = requestMessageField.GetValue(message);
FieldInfo streamField = requestMessage.GetType().GetField("_stream", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
Stream originalStream = (Stream)streamField.GetValue(requestMessage);
streamField.SetValue(requestMessage, substituteStream);
return(originalStream);
}
