/// <summary>
/// Negotiates the response based on the given result and context.
/// </summary>
/// <param name="routeResult">The route result.</param>
/// <param name="context">The context.</param>
/// <returns>A <see cref="Response" />.</returns>
public Response NegotiateResponse(dynamic routeResult, NancyContext context)
{
Response response;
if (TryCastResultToResponse(routeResult, out response))
{
context.WriteTraceLog(sb =>
sb.AppendLine("[DefaultResponseNegotiator] Processing as real response"));
return(response);
}
context.WriteTraceLog(sb =>
sb.AppendLine("[DefaultResponseNegotiator] Processing as negotiation"));
NegotiationContext negotiationContext = GetNegotiationContext(routeResult, context);
var coercedAcceptHeaders = this.GetCoercedAcceptHeaders(context).ToArray();
context.WriteTraceLog(sb => GetAccepHeaderTraceLog(context, negotiationContext, coercedAcceptHeaders, sb));
var compatibleHeaders = this.GetCompatibleHeaders(coercedAcceptHeaders, negotiationContext, context).ToArray();
if (!compatibleHeaders.Any())
{
context.WriteTraceLog(sb =>
sb.AppendLine("[DefaultResponseNegotiator] Unable to negotiate response - no headers compatible"));
return(new NotAcceptableResponse());
}
return(CreateResponse(compatibleHeaders, negotiationContext, context));
}
/// <summary>
/// Creates a response from the compatible headers.
/// </summary>
/// <param name="compatibleHeaders">The compatible headers.</param>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="context">The context.</param>
/// <returns>A <see cref="Response"/>.</returns>
private Response CreateResponse(IList <CompatibleHeader> compatibleHeaders,
NegotiationContext negotiationContext,
NancyContext context)
{
var response = NegotiateResponse(compatibleHeaders, negotiationContext, context);
if (response == null)
{
context.WriteTraceLog(sb =>
sb.AppendLine("[DefaultResponseNegotiator] Unable to negotiate response - no processors returned valid response"));
response = new NotAcceptableResponse();
}
response.WithHeader("Vary", "Accept");
this.AddLinkHeader(compatibleHeaders, response, context.Request.Url);
SetStatusCode(negotiationContext, response);
SetReasonPhrase(negotiationContext, response);
AddCookies(negotiationContext, response);
if (response is NotAcceptableResponse)
{
return(response);
}
AddContentTypeHeader(negotiationContext, response);
AddNegotiatedHeaders(negotiationContext, response);
return(response);
}
/// <summary>
/// Prioritizes the response processors and tries to negotiate a response.
/// </summary>
/// <param name="compatibleHeaders">The compatible headers.</param>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="context">The context.</param>
/// <returns>Response.</returns>
private static Response NegotiateResponse(
IEnumerable <CompatibleHeader> compatibleHeaders,
NegotiationContext negotiationContext,
NancyContext context)
{
foreach (var compatibleHeader in compatibleHeaders)
{
var prioritizedProcessors = compatibleHeader.Processors
.OrderByDescending(x => x.Item2.ModelResult)
.ThenByDescending(x => x.Item2.RequestedContentTypeResult);
foreach (var prioritizedProcessor in prioritizedProcessors)
{
var processorType = prioritizedProcessor.Item1.GetType();
context.WriteTraceLog(sb =>
sb.AppendFormat("[DefaultResponseNegotiator] Invoking processor: {0}\n", processorType));
var mediaRangeModel = negotiationContext.GetModelForMediaRange(compatibleHeader.MediaRange);
var response = prioritizedProcessor.Item1.Process(compatibleHeader.MediaRange, mediaRangeModel, context);
if (response != null)
{
return(response);
}
}
}
return(null);
}
/// <summary>
/// Adds the negotiated headers from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddNegotiatedHeaders(NegotiationContext negotiationContext, Response response)
{
foreach (var header in negotiationContext.Headers)
{
response.Headers[header.Key] = header.Value;
}
}
/// <summary>
/// Sets the status code from the <see cref="NegotiationContext"/> on the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void SetStatusCode(NegotiationContext negotiationContext, Response response)
{
if (negotiationContext.StatusCode.HasValue)
{
response.StatusCode = negotiationContext.StatusCode.Value;
}
}
/// <summary>
/// Sets the reason phrase from the <see cref="NegotiationContext"/> on the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void SetReasonPhrase(NegotiationContext negotiationContext, Response response)
{
if (negotiationContext.ReasonPhrase != null)
{
response.ReasonPhrase = negotiationContext.ReasonPhrase;
}
}
/// <summary>
/// Adds the cookies from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddCookies(NegotiationContext negotiationContext, Response response)
{
foreach (var cookie in negotiationContext.Cookies)
{
response.Cookies.Add(cookie);
}
}
/// <summary>
/// Adds the content type header from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddContentTypeHeader(NegotiationContext negotiationContext, Response response)
{
if (negotiationContext.Headers.ContainsKey("Content-Type"))
{
response.ContentType = negotiationContext.Headers["Content-Type"];
negotiationContext.Headers.Remove("Content-Type");
}
}
/// <summary>
/// Adds the content type header from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddContentTypeHeader(NegotiationContext negotiationContext, Response response)
{
if (negotiationContext.Headers.ContainsKey("Content-Type"))
{
response.ContentType = negotiationContext.Headers["Content-Type"];
negotiationContext.Headers.Remove("Content-Type");
}
}
/// <summary>
/// Adds the content type header from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddContentTypeHeader(NegotiationContext negotiationContext, Response response)
{
string contentType;
if (negotiationContext.Headers.TryGetValue("Content-Type", out contentType))
{
response.ContentType = contentType;
negotiationContext.Headers.Remove("Content-Type");
}
}
private static IEnumerable <Tuple <string, decimal> > GetCompatibleHeaders(
IEnumerable <Tuple <string, decimal> > coercedAcceptHeaders,
NegotiationContext negotiationContext)
{
var permissableMediaRanges = negotiationContext.PermissableMediaRanges;
if (permissableMediaRanges.Any(mr => mr.IsWildcard))
{
return(coercedAcceptHeaders.Where(header => header.Item2 > 0m));
}
return(coercedAcceptHeaders
.Where(header => header.Item2 > 0m)
.SelectMany(header => permissableMediaRanges
.Where(mr => mr.Matches(header.Item1))
.Select(mr => Tuple.Create(mr.ToString(), header.Item2))));
}
private IEnumerable <CompatibleHeader> GetCompatibleHeaders(
IEnumerable <Tuple <string, decimal> > coercedAcceptHeaders,
NegotiationContext negotiationContext,
NancyContext context)
{
var acceptHeaders = GetCompatibleHeaders(coercedAcceptHeaders, negotiationContext);
foreach (var header in acceptHeaders)
{
var mediaRangeModel = negotiationContext.GetModelForMediaRange(header.Item1);
IEnumerable <Tuple <IResponseProcessor, ProcessorMatch> > compatibleProcessors =
this.GetCompatibleProcessorsByHeader(header.Item1, mediaRangeModel, context);
if (compatibleProcessors.Any())
{
yield return(new CompatibleHeader(header.Item1, compatibleProcessors));
}
}
}
private static void GetAccepHeaderTraceLog(
NancyContext context,
NegotiationContext negotiationContext,
Tuple <string, decimal>[] coercedAcceptHeaders,
StringBuilder sb)
{
var allowableFormats = negotiationContext.PermissableMediaRanges
.Select(mr => mr.ToString())
.Aggregate((t1, t2) => t1 + ", " + t2);
var originalAccept = context.Request.Headers["accept"].Any()
? string.Join(", ", context.Request.Headers["accept"])
: "None";
var coercedAccept = coercedAcceptHeaders.Any()
? coercedAcceptHeaders.Select(h => h.Item1).Aggregate((t1, t2) => t1 + ", " + t2)
: "None";
sb.AppendFormat("[DefaultResponseNegotiator] Original accept header: {0}\n", originalAccept);
sb.AppendFormat("[DefaultResponseNegotiator] Coerced accept header: {0}\n", coercedAccept);
sb.AppendFormat("[DefaultResponseNegotiator] Acceptable media ranges: {0}\n", allowableFormats);
}
public void Should_reset_negotiation_context()
{
// Given
var context = new NancyContext();
var negotiationContext = new NegotiationContext { ViewName = "Index" };
context.NegotiationContext = negotiationContext;
// When
this.statusCodeHandler.Handle(HttpStatusCode.InternalServerError, context);
// Then
Assert.Equal(context.NegotiationContext.ViewName, null);
}
private static void GetAccepHeaderTraceLog(
NancyContext context,
NegotiationContext negotiationContext,
Tuple<string, decimal>[] coercedAcceptHeaders,
StringBuilder sb)
{
var allowableFormats = negotiationContext.PermissableMediaRanges
.Select(mr => mr.ToString())
.Aggregate((t1, t2) => t1 + ", " + t2);
var originalAccept = context.Request.Headers["accept"].Any()
? string.Join(", ", context.Request.Headers["accept"])
: "None";
var coercedAccept = coercedAcceptHeaders.Any()
? coercedAcceptHeaders.Select(h => h.Item1).Aggregate((t1, t2) => t1 + ", " + t2)
: "None";
sb.AppendFormat("[DefaultResponseNegotiator] Original accept header: {0}\n", originalAccept);
sb.AppendFormat("[DefaultResponseNegotiator] Coerced accept header: {0}\n", coercedAccept);
sb.AppendFormat("[DefaultResponseNegotiator] Acceptable media ranges: {0}\n", allowableFormats);
}
/// <summary>
/// Creates a response from the compatible headers.
/// </summary>
/// <param name="compatibleHeaders">The compatible headers.</param>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="context">The context.</param>
/// <returns>A <see cref="Response"/>.</returns>
private static Response CreateResponse(
IList<CompatibleHeader> compatibleHeaders,
NegotiationContext negotiationContext,
NancyContext context)
{
var response = NegotiateResponse(compatibleHeaders, negotiationContext, context);
if (response == null)
{
context.WriteTraceLog(sb =>
sb.AppendLine("[DefaultResponseNegotiator] Unable to negotiate response - no processors returned valid response"));
response = new NotAcceptableResponse();
}
response.WithHeader("Vary", "Accept");
AddLinkHeader(compatibleHeaders, response, context.Request.Url);
SetStatusCode(negotiationContext, response);
SetReasonPhrase(negotiationContext, response);
AddCookies(negotiationContext, response);
if (response is NotAcceptableResponse)
{
return response;
}
AddContentTypeHeader(negotiationContext, response);
AddNegotiatedHeaders(negotiationContext, response);
return response;
}
/// <summary>
/// Prioritizes the response processors and tries to negotiate a response.
/// </summary>
/// <param name="compatibleHeaders">The compatible headers.</param>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="context">The context.</param>
/// <returns>Response.</returns>
private static Response NegotiateResponse(
IEnumerable<CompatibleHeader> compatibleHeaders,
NegotiationContext negotiationContext,
NancyContext context)
{
foreach (var compatibleHeader in compatibleHeaders)
{
var prioritizedProcessors = compatibleHeader.Processors
.OrderByDescending(x => x.Item2.ModelResult)
.ThenByDescending(x => x.Item2.RequestedContentTypeResult);
foreach (var prioritizedProcessor in prioritizedProcessors)
{
var processorType = prioritizedProcessor.Item1.GetType();
context.WriteTraceLog(sb =>
sb.AppendFormat("[DefaultResponseNegotiator] Invoking processor: {0}\n", processorType));
var mediaRangeModel = negotiationContext.GetModelForMediaRange(compatibleHeader.MediaRange);
var response = prioritizedProcessor.Item1.Process(compatibleHeader.MediaRange, mediaRangeModel, context);
if (response != null)
{
return response;
}
}
}
return null;
}
private static IEnumerable<Tuple<string, decimal>> GetCompatibleHeaders(
IEnumerable<Tuple<string, decimal>> coercedAcceptHeaders,
NegotiationContext negotiationContext)
{
var permissableMediaRanges = negotiationContext.PermissableMediaRanges;
if (permissableMediaRanges.Any(mr => mr.IsWildcard))
{
return coercedAcceptHeaders.Where(header => header.Item2 > 0m);
}
return coercedAcceptHeaders
.Where(header => header.Item2 > 0m)
.SelectMany(header => permissableMediaRanges
.Where(mr => mr.Matches(header.Item1))
.Select(mr => Tuple.Create(mr.ToString(), header.Item2)));
}
/// <summary>
/// Sets the reason phrase from the <see cref="NegotiationContext"/> on the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void SetReasonPhrase(NegotiationContext negotiationContext, Response response)
{
if (negotiationContext.ReasonPhrase != null)
{
response.ReasonPhrase = negotiationContext.ReasonPhrase;
}
}
/// <summary>
/// Sets the status code from the <see cref="NegotiationContext"/> on the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void SetStatusCode(NegotiationContext negotiationContext, Response response)
{
if (negotiationContext.StatusCode.HasValue)
{
response.StatusCode = negotiationContext.StatusCode.Value;
}
}
private IEnumerable<CompatibleHeader> GetCompatibleHeaders(
IEnumerable<Tuple<string, decimal>> coercedAcceptHeaders,
NegotiationContext negotiationContext,
NancyContext context)
{
var acceptHeaders = GetCompatibleHeaders(coercedAcceptHeaders, negotiationContext);
foreach (var header in acceptHeaders)
{
var mediaRangeModel = negotiationContext.GetModelForMediaRange(header.Item1);
IEnumerable<Tuple<IResponseProcessor, ProcessorMatch>> compatibleProcessors =
this.GetCompatibleProcessorsByHeader(header.Item1, mediaRangeModel, context);
if (compatibleProcessors.Any())
{
yield return new CompatibleHeader(header.Item1, compatibleProcessors);
}
}
}
/// <summary>
/// Adds the cookies from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddCookies(NegotiationContext negotiationContext, Response response)
{
foreach (var cookie in negotiationContext.Cookies)
{
response.Cookies.Add(cookie);
}
}
/// <summary>
/// Adds the negotiated headers from the <see cref="NegotiationContext"/> to the <see cref="Response"/>.
/// </summary>
/// <param name="negotiationContext">The negotiation context.</param>
/// <param name="response">The response.</param>
private static void AddNegotiatedHeaders(NegotiationContext negotiationContext, Response response)
{
foreach (var header in negotiationContext.Headers)
{
response.Headers[header.Key] = header.Value;
}
}
