public void CreateODataErrorFromExceptionArgsShouldCreateODataErrorWithCustomAnnotationsAndInstanceAnnotations()
{
DataServiceException dse = new DataServiceException(500, "500", "Test message", "en-US", null);
HandleExceptionArgs args = new HandleExceptionArgs(dse, responseWritten:false, contentType:"application/json",verboseResponse:true);
ODataError error = args.CreateODataError();
error.InstanceAnnotations.As<object>().Should().BeSameAs(args.InstanceAnnotations);
}
/// <summary>Method to handle a data service exception during processing.</summary>
/// <param name="args">Exception handling description.</param>
void IDataServiceHost.ProcessException(HandleExceptionArgs args)
{
// This would typically set headers on the host.
WebUtil.CheckArgumentNull(args, "args");
Debug.Assert(CommonUtil.IsCatchableExceptionType(args.Exception), "CommonUtil.IsCatchableExceptionType(args.Exception)");
this.responseStatusCode = args.ResponseStatusCode;
this.responseHeaders[HttpResponseHeader.ContentType] = args.ResponseContentType;
this.responseHeaders[HttpResponseHeader.Allow] = args.ResponseAllowHeader;
}
/// <summary>
/// Method to handle a data service exception during processing.
/// </summary>
/// <param name="args">Exception handling description.</param>
void IDataServiceHost.ProcessException(HandleExceptionArgs args)
{
WebUtil.CheckArgumentNull(args, "args");
Debug.Assert(this.operationContext != null, "this.operationContext != null");
this.errorFound = true;
if (!args.ResponseWritten)
{
((IDataServiceHost)this).ResponseStatusCode = args.ResponseStatusCode;
((IDataServiceHost)this).ResponseContentType = args.ResponseContentType;
if (args.ResponseAllowHeader != null)
{
this.operationContext.OutgoingResponse.Headers[HttpResponseHeader.Allow] = args.ResponseAllowHeader;
}
}
}
/// <summary>
/// Prevents a default instance of the <see cref="ErrorHandler"/> class from being created.
/// </summary>
/// <param name="exception">The exception to be written.</param>
/// <param name="verbose">if set to <c>true</c> indicates verbose errors should be written.</param>
/// <param name="responseVersion">The response version.</param>
/// <param name="acceptableContentTypes">The acceptable content types.</param>
/// <param name="requestAcceptCharsetHeader">The request accept charset header.</param>
private ErrorHandler(Exception exception, bool verbose, Version responseVersion, string acceptableContentTypes, string requestAcceptCharsetHeader)
{
this.contentType = GetErrorResponseContentType(acceptableContentTypes, responseVersion);
this.encoding = GetEncodingForError(requestAcceptCharsetHeader);
// [GQL Failure, ODataLib integration] Server does not write charset in content-type header on error responses
// [GQL Failure, Astoria-ODataLib Integration] ContentType provided to DataService.HandleException does not match final header value in $batch
// With the integration of ODataLib into the server-side , batch-parts which have top level error messages in them
// have the charset header value appended to the content-type of the response.
// To retain a consistent behavior between top level error messages in the batch and non-batch cases, we will append
// the charset header to the response content type before passing it to the HandleException method on the IDataServiceHost.
this.contentTypeWithCharset = string.Concat(this.contentType, ";", XmlConstants.HttpCharsetParameter, "=", this.encoding.WebName);
this.exceptionArgs = new HandleExceptionArgs(exception, false, this.contentTypeWithCharset, verbose);
Debug.Assert(responseVersion != null, "responseVersion != null");
this.responseVersion = responseVersion;
}
/// <summary>
/// Prevents a default instance of the <see cref="ErrorHandler"/> class from being created.
/// </summary>
/// <param name="exception">The exception to be written.</param>
/// <param name="verbose">if set to <c>true</c> indicates verbose errors should be written.</param>
/// <param name="responseVersion">The response version.</param>
/// <param name="acceptableContentTypes">The acceptable content types.</param>
/// <param name="requestAcceptCharsetHeader">The request accept charset header.</param>
private ErrorHandler(Exception exception, bool verbose, Version responseVersion, string acceptableContentTypes, string requestAcceptCharsetHeader)
{
this.contentType = GetErrorResponseContentType(acceptableContentTypes, responseVersion);
this.encoding = GetEncodingForError(requestAcceptCharsetHeader);
// [GQL Failure, ODataLib integration] Server does not write charset in content-type header on error responses
// [GQL Failure, Astoria-ODataLib Integration] ContentType provided to DataService.HandleException does not match final header value in $batch
// With the integration of ODataLib into the server-side , batch-parts which have top level error messages in them
// have the charset header value appended to the content-type of the response.
// To retain a consistent behavior between top level error messages in the batch and non-batch cases, we will append
// the charset header to the response content type before passing it to the HandleException method on the IDataServiceHost.
this.contentTypeWithCharset = string.Concat(this.contentType, ";", XmlConstants.HttpCharsetParameter, "=", this.encoding.WebName);
this.exceptionArgs = new HandleExceptionArgs(exception, false, this.contentTypeWithCharset, verbose);
Debug.Assert(responseVersion != null, "responseVersion != null");
this.responseVersion = responseVersion;
}
/// <summary>
/// Handles an exception that occurred while writing a response.
/// </summary>
/// <param name="service">Data service doing the processing.</param>
/// <param name="exception">The exception that was thrown.</param>
/// <param name="responseMessage">The response message.</param>
/// <param name="messageWriter">The message writer, if null this will fall back to writing a raw XML error to the stream.</param>
/// <param name="encoding">The encoding to while writing the error.</param>
/// <param name="responseStream">The response stream to write the error to.</param>
/// <param name="messageWriterBuilder">MessageWriterBuilder to use in case a new ODataMessageWriter needs to be constructed.</param>
internal static void HandleExceptionWhileWriting(IDataService service, Exception exception, IODataResponseMessage responseMessage, ODataMessageWriter messageWriter, Encoding encoding, Stream responseStream, MessageWriterBuilder messageWriterBuilder)
{
Debug.Assert(service != null, "service != null");
Debug.Assert(service.Configuration != null, "service.Configuration != null");
Debug.Assert(exception != null, "exception != null");
Debug.Assert(CommonUtil.IsCatchableExceptionType(exception), "CommonUtil.IsCatchableExceptionType(exception)");
Debug.Assert(responseMessage != null, "responseMessage != null");
string contentType = responseMessage.GetHeader(XmlConstants.HttpContentType);
HandleExceptionArgs args = new HandleExceptionArgs(exception, true, contentType, service.Configuration.UseVerboseErrors);
service.InternalHandleException(args);
service.OperationContext.RequestMessage.ProcessException(args);
ODataError error = args.CreateODataError();
WriteErrorWithFallbackForXml(messageWriter, encoding, responseStream, args, error, messageWriterBuilder);
}
/// <summary>Method to handle a data service exception during processing.</summary>
/// <param name="args">Exception handling description.</param>
public void ProcessException(HandleExceptionArgs args)
{
processExceptionCalled = true;
if (!args.ResponseWritten)
{
this.ResponseStatusCode = args.ResponseStatusCode;
this.ResponseContentType = args.ResponseContentType;
throw new Exception(args.Exception.Message);
}
}
/// <summary>Method to handle a data service exception during processing.</summary>
/// <param name="args">Exception handling description.</param>
internal void ProcessException(HandleExceptionArgs args)
{
this.host.ProcessException(args);
}
public void ProcessException(HandleExceptionArgs args)
{
if (this.ProcessExceptionCallBack != null)
{
this.ProcessExceptionCallBack(args);
}
else
{
throw new NotImplementedException();
}
}
public void ProcessException(HandleExceptionArgs args)
{
throw new NotImplementedException();
}
/// <summary>
/// Handles an exception that occurred while writing a response.
/// </summary>
/// <param name="service">Data service doing the processing.</param>
/// <param name="exception">The exception that was thrown.</param>
/// <param name="responseMessage">The response message.</param>
/// <param name="messageWriter">The message writer, if null this will fall back to writing a raw XML error to the stream.</param>
/// <param name="encoding">The encoding to while writing the error.</param>
/// <param name="responseStream">The response stream to write the error to.</param>
/// <param name="messageWriterBuilder">MessageWriterBuilder to use in case a new ODataMessageWriter needs to be constructed.</param>
internal static void HandleExceptionWhileWriting(IDataService service, Exception exception, IODataResponseMessage responseMessage, ODataMessageWriter messageWriter, Encoding encoding, Stream responseStream, MessageWriterBuilder messageWriterBuilder)
{
Debug.Assert(service != null, "service != null");
Debug.Assert(service.Configuration != null, "service.Configuration != null");
Debug.Assert(exception != null, "exception != null");
Debug.Assert(CommonUtil.IsCatchableExceptionType(exception), "CommonUtil.IsCatchableExceptionType(exception)");
Debug.Assert(responseMessage != null, "responseMessage != null");
string contentType = responseMessage.GetHeader(XmlConstants.HttpContentType);
HandleExceptionArgs args = new HandleExceptionArgs(exception, true, contentType, service.Configuration.UseVerboseErrors);
service.InternalHandleException(args);
service.OperationContext.RequestMessage.ProcessException(args);
ODataError error = args.CreateODataError();
WriteErrorWithFallbackForXml(messageWriter, encoding, responseStream, args, error, messageWriterBuilder);
}
public void InternalHandleException(HandleExceptionArgs args)
{
}
/// <summary>
/// Writes the error with fallback logic for XML cases where the writer is in an error state and a new writer must be created.
/// </summary>
/// <param name="messageWriter">The message writer.</param>
/// <param name="encoding">The encoding to use for the error if we have to fallback.</param>
/// <param name="responseStream">The response stream to write to in the fallback case.</param>
/// <param name="args">The args for the error.</param>
/// <param name="error">The error to write.</param>
/// <param name="messageWriterBuilder">MessageWriterBuilder to use if a new ODataMessageWriter needs to be constructed.</param>
private static void WriteErrorWithFallbackForXml(ODataMessageWriter messageWriter, Encoding encoding, Stream responseStream, HandleExceptionArgs args, ODataError error, MessageWriterBuilder messageWriterBuilder)
{
Debug.Assert(args != null, "args != null");
#if DEBUG
Debug.Assert(args.ProcessExceptionWasCalled, "ProcessException was not called by the time we tried to serialze this error message with ODataLib.");
#endif
if (messageWriter != null)
{
try
{
// If the XmlWriter inside the ODataMessageWriter had entered Error state, ODataMessageWriter.WriteError would throw an InvalidOperationException
// when we try to write to it. Note that XmlWriter doesn't always throw an XmlException when it enters Error state.
// The right thing to do is we don't write any more because at this point we don't know what's been written to the underlying
// stream. However we still should flush the writer to make sure that all the content that was written but is sitting in the buffers actually appears
// in the stream before writing the instream error. Otherwise the buffer will be flushed when disposing the writer later and we would end up with
// either content written after the instream error (this would also result in having the Xml declaration in the middle of the payload -
// [Astoria-ODataLib-Integration] In-stream errors due to XmlExceptions are written out backwards (error before partial valid payload)) or,
// hypothetically, the instream error in the middle of the other content that was already partially written. For example we can end up with a payload that
// looks like <element attr="val<m:error... The XmlReader would not be able to parse the error payload in this case. Disposing the writer will flush the buffer.
// It is fine to do it since the writer is not usable at this point anyways. Also note that the writer will be disposed more than once (e.g. in finally block
// in ResponseBodySerializer) but only the first call will have any effect.
// However since in the versions we shipped we always create a new XmlWriter to serialize the error payload when the existing
// one is in error state, we will continue to do the same to avoid introducing any breaking change here.
messageWriter.WriteError(error, args.UseVerboseErrors);
}
catch (ODataException e)
{
// Yikes, ODataLib threw while writing the error. This tends to happen if the service author did something invalid during custom
// error handling, such as add an custom instance annotation to the error payload. In this dire case, we treat it almost like
// an in-stream error, and abort the previous writing. We write out the new error. Note that this will produce an invalid payload like
// the situation noted above with XmlWriter errors.
WebUtil.Dispose(messageWriter);
messageWriterBuilder.SetMessageForErrorInError();
var newErrorWriter = messageWriterBuilder.CreateWriter();
ODataError errorWhileWritingOtherError = new ODataError()
{
ErrorCode = "500",
InnerError = new ODataInnerError(e),
Message = Strings.ErrorHandler_ErrorWhileWritingError
};
newErrorWriter.WriteError(errorWhileWritingOtherError, args.UseVerboseErrors);
}
catch (InvalidOperationException)
{
Debug.Assert(ContentTypeUtil.IsNotJson(args.ResponseContentType), "Should never get here for JSON responses");
WebUtil.Dispose(messageWriter);
// if either an InvalidOperationException was encountered (see comment above) or the message writer was null, write the error out manually.
Debug.Assert(responseStream != null, "responseStream != null");
using (XmlWriter xmlWriter = XmlWriter.Create(responseStream, XmlUtil.CreateXmlWriterSettings(encoding)))
{
ErrorUtils.WriteXmlError(xmlWriter, error, args.UseVerboseErrors, MaxInnerErrorDepth);
}
}
}
}
/// <summary>
/// Writes the error with fallback logic for XML cases where the writer is in an error state and a new writer must be created.
/// </summary>
/// <param name="messageWriter">The message writer.</param>
/// <param name="encoding">The encoding to use for the error if we have to fallback.</param>
/// <param name="responseStream">The response stream to write to in the fallback case.</param>
/// <param name="args">The args for the error.</param>
/// <param name="error">The error to write.</param>
/// <param name="messageWriterBuilder">MessageWriterBuilder to use if a new ODataMessageWriter needs to be constructed.</param>
private static void WriteErrorWithFallbackForXml(ODataMessageWriter messageWriter, Encoding encoding, Stream responseStream, HandleExceptionArgs args, ODataError error, MessageWriterBuilder messageWriterBuilder)
{
Debug.Assert(args != null, "args != null");
#if DEBUG
Debug.Assert(args.ProcessExceptionWasCalled, "ProcessException was not called by the time we tried to serialze this error message with ODataLib.");
#endif
if (messageWriter != null)
{
try
{
// If the XmlWriter inside the ODataMessageWriter had entered Error state, ODataMessageWriter.WriteError would throw an InvalidOperationException
// when we try to write to it. Note that XmlWriter doesn't always throw an XmlException when it enters Error state.
// The right thing to do is we don't write any more because at this point we don't know what's been written to the underlying
// stream. However we still should flush the writer to make sure that all the content that was written but is sitting in the buffers actually appears
// in the stream before writing the instream error. Otherwise the buffer will be flushed when disposing the writer later and we would end up with
// either content written after the instream error (this would also result in having the Xml declaration in the middle of the payload -
// [Astoria-ODataLib-Integration] In-stream errors due to XmlExceptions are written out backwards (error before partial valid payload)) or,
// hypothetically, the instream error in the middle of the other content that was already partially written. For example we can end up with a payload that
// looks like <element attr="val<m:error... The XmlReader would not be able to parse the error payload in this case. Disposing the writer will flush the buffer.
// It is fine to do it since the writer is not usable at this point anyways. Also note that the writer will be disposed more than once (e.g. in finally block
// in ResponseBodySerializer) but only the first call will have any effect.
// However since in the versions we shipped we always create a new XmlWriter to serialize the error payload when the existing
// one is in error state, we will continue to do the same to avoid introducing any breaking change here.
messageWriter.WriteError(error, args.UseVerboseErrors);
}
catch (ODataException e)
{
// Yikes, ODataLib threw while writing the error. This tends to happen if the service author did something invalid during custom
// error handling, such as add an custom instance annotation to the error payload. In this dire case, we treat it almost like
// an in-stream error, and abort the previous writing. We write out the new error. Note that this will produce an invalid payload like
// the situation noted above with XmlWriter errors.
WebUtil.Dispose(messageWriter);
messageWriterBuilder.SetMessageForErrorInError();
var newErrorWriter = messageWriterBuilder.CreateWriter();
ODataError errorWhileWritingOtherError = new ODataError()
{
ErrorCode = "500",
InnerError = new ODataInnerError(e),
Message = Strings.ErrorHandler_ErrorWhileWritingError
};
newErrorWriter.WriteError(errorWhileWritingOtherError, args.UseVerboseErrors);
}
catch (InvalidOperationException)
{
Debug.Assert(ContentTypeUtil.IsNotJson(args.ResponseContentType), "Should never get here for JSON responses");
WebUtil.Dispose(messageWriter);
// if either an InvalidOperationException was encountered (see comment above) or the message writer was null, write the error out manually.
Debug.Assert(responseStream != null, "responseStream != null");
using (XmlWriter xmlWriter = XmlWriter.Create(responseStream, XmlUtil.CreateXmlWriterSettings(encoding)))
{
ErrorUtils.WriteXmlError(xmlWriter, error, args.UseVerboseErrors, MaxInnerErrorDepth);
}
}
}
}
/// <summary>Method to handle a data service exception during processing.</summary>
/// <param name="args">Exception handling description.</param>
void IDataServiceHost.ProcessException(HandleExceptionArgs args)
{
// This would typically set headers on the host.
WebUtil.CheckArgumentNull(args, "args");
Debug.Assert(CommonUtil.IsCatchableExceptionType(args.Exception), "CommonUtil.IsCatchableExceptionType(args.Exception)");
this.responseStatusCode = args.ResponseStatusCode;
this.responseHeaders[HttpResponseHeader.ContentType] = args.ResponseContentType;
this.responseHeaders[HttpResponseHeader.Allow] = args.ResponseAllowHeader;
}
public void ProcessException(HandleExceptionArgs args)
{
this.plainException = args.Exception;
DataServiceException dse = args.Exception as DataServiceException;
if (dse != null)
{
if (dse.StatusCode == (int)HttpStatusCode.NotModified)
{
// 304 is not a failure, we let the server handle it.
return;
}
}
if (AllowServerToSerializeException.Value)
{
this.ResponseStatusCode = args.ResponseStatusCode;
this.ResponseContentType = args.ResponseContentType;
}
else
{
// set the right status code and content type
this.ResponseStatusCode = args.ResponseStatusCode;
this.ResponseContentType = "text/plain";
// write the error message in the payload
StreamWriter writer = new StreamWriter(this.responseStream);
writer.WriteLine("TestServiceHost.ProcessException special pre-writing handling:");
writer.Write(args.Exception.Message);
writer.Flush();
// Re-throw the exception. This makes things consistent for tests,
// which except an exception from HttpWebRequest.StatusCode <> 200 as well.
throw new WebException("WebException from TestServiceHost.ProcessException", args.Exception);
}
}
/// <summary>
/// Method to handle a data service exception during processing.
/// </summary>
/// <param name="args">Exception handling description.</param>
void IDataServiceHost.ProcessException(HandleExceptionArgs args)
{
WebUtil.CheckArgumentNull(args, "args");
Debug.Assert(this.operationContext != null, "this.operationContext != null");
this.errorFound = true;
if (!args.ResponseWritten)
{
((IDataServiceHost)this).ResponseStatusCode = args.ResponseStatusCode;
((IDataServiceHost)this).ResponseContentType = args.ResponseContentType;
if (args.ResponseAllowHeader != null)
{
this.operationContext.OutgoingResponse.Headers[HttpResponseHeader.Allow] = args.ResponseAllowHeader;
}
}
}
