/// <summary>
/// Replace the inner HTTP request 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="reader">ODataMessageReader which has not read yet.</param>
/// <param name="substituteStream">Replacement stream.</param>
public static void SubstituteRequestStream(this ODataMessageReader reader, Stream substituteStream)
{
FieldInfo messageField = reader.GetType().GetField("message", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
object message = messageField.GetValue(reader);
FieldInfo requestMessageField = message.GetType().GetField("requestMessage", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
object requestMessage = requestMessageField.GetValue(message);
FieldInfo streamField = requestMessage.GetType().GetField("_stream", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
streamField.SetValue(requestMessage, substituteStream);
}
/// <summary>
/// Replace the inner HTTP request 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 ODataMessageReader, so reflection must be used to modify it.
/// </summary>
/// <param name="reader">ODataMessageReader which has not read yet.</param>
/// <param name="substituteStream">Replacement stream.</param>
public static void SubstituteRequestStream(this ODataMessageReader reader, Stream substituteStream)
{
FieldInfo messageField = reader.GetType().GetField("message", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
object message = messageField.GetValue(reader);
// Throw an exception if the message field does not exist in ODataMessageReader class anymore.
if (message == null)
{
throw new Exception("The request body cannot be translated because the 'message' field does not exist in ODataMessageReader.");
}
FieldInfo requestMessageField = message.GetType().GetField("requestMessage", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy);
var requestMessage = requestMessageField.GetValue(message) as ODataMigrationMessageWrapper;
// Throw an exception if the requestMessage field does not exist in ODataRequestMessage class anymore.
if (requestMessage == null)
{
throw new Exception("The request body cannot be translated because the 'requestMessage' field does not exist in ODataRequestMessage or it cannot be cast to ODataMigrationMessageWrapper.");
}
requestMessage.Stream = substituteStream;
}
