I need to access the HTTP response headers that are to be returned to the client from a WCF Service. Accessing the HTTPContext is easy(through HttpContext.Current.Response), but what is the event/extension/behavior that is executed lastly, when the StatusCode is already set (for ex. if the status is 500)?
EDIT: Message Inspectors don't seem to be a good solution here, because at the time they run, the status code isn't set yet. (At least in my trial that was the case)
You can access all headers on WebOperationContext.Current.IncomingRequest, like this:
IncomingWebRequestContext request = WebOperationContext.Current.IncomingRequest;
WebHeaderCollection headers = request.Headers;
Console.WriteLine("-------------------------------------------------------");
foreach (string headerName in headers.AllKeys)
{
Console.WriteLine(headerName + ": " + headers[headerName]);
}
Console.WriteLine("-------------------------------------------------------");
See here
Simplest way for having control on the Headers is to use Message contracts.
Use Message Inspectors to monitor the message right after receiving it at the Service end.
In an extreme case, where you are not satisfied with any other standard routes, you can go for POX (Plain Old XML) type operations where you would be dealing with raw XML message.
Related
This article, https://devblogs.microsoft.com/aspnet/improvements-in-net-core-3-0-for-troubleshooting-and-monitoring-distributed-apps/, tells me that the field TraceId is available as a correlation id, which is great!
info: Microsoft.AspNetCore.Routing.EndpointMiddleware[1]
=> ConnectionId:0HLR1BR0PL1CH
=> RequestPath:/weatherforecastproxy
RequestId:0HLR1BR0PL1CH:00000001,
SpanId:|363a800a-4cf070ad93fe3bd8.,
TraceId:363a800a-4cf070ad93fe3bd8,
ParentId: Executed endpoint 'FrontEndApp.Controllers.WeatherForecastProxyController.Get
(FrontEndApp)'
In fact, I can see that in our log sink this works as advertised: When web application A serves a request and in doing so invokes web application B, both of them write the same TraceId value to the log.
As far as I understand, any ASP.NET Core application that receives an incoming Request-Id header will attach the same header to outgoing requests, but if the header does not exist on the incoming request, an new value will be generated for the outgoing request.
We have been asked to add that value to the response from web application A, but it is (not surprisingly) not available on the incoming request.
I have been looking at the System.Diagnostics.Activity class, but accessing Activity.Current isn't giving me an instance with anything useful - the TraceID is just {} - i.e. empty.
My question is this: How can I access the TraceId value in the context of a web application?
-S
I had the same problem when I tried to add a header with TraceId value.
Doing some tests with ModelValidation, I saw then in this kind of error response the "traceId" value was correct, but I couldn't obtain this value from http context variable in any way.
Then I went to net core source code to see DefaultProblemDetailsFactory implementation and surprise! The "traceId" value is obtained doing this:
var traceId = Activity.Current?.Id ?? httpContext?.TraceIdentifier;
Yes, you can get THE traceId using Activity static variable.
You can get tracid and spanid in dictionary.
using var subject = _tracer.BuildSpan($"Operation").StartActive();
var spanContext = subject.Span.Context;
var dictionary = new Dictionary<string, string>();
_tracer.Inject(spanContext, BuiltinFormats.TextMap, new TextMapInjectAdapter(dictionary));
A parse server cloud function is defined via
Parse.Cloud.define("hello", function(request, response) {..});
on the response, I can call response.success(X) and response.error(Y), and that sets the http response code and the body of the response.
But how do I define a different code, like created (201)?
And how do I set the headers of the response?
thanks, Tim
You are allowed to return any valid JSON from response.success(). Therefore, you could create an object with fields such as code, message, and value, so you can set the code, give it a string descriptor, and pass back the value you normally would, if there is one. This seems to accomplish what you need, though you will have to keep track of those codes across your platforms. I recommend looking up standard http response codes and make sure you don't overlap with any standards.
Is there any way to use the response of a wcf service method request as an input for the next request in same orchestration and return the response of the first request as well as the response of the second request as out put in BizTalk?
Eg :
My first request gives a response as "a"
Give this response "a" as request to the 2nd request and gets the response as "b"
Return the response as "a" and "b".
Is this possible?
Yes. You could either create a map from Response 1 to Request 2, and also create a multiple input message map from Response 1 and Response 2 to your final output message.
If the messages involved don't have any repeating structures, it may be enough to distinguish the fields that you need to be concerned with and just use a ConstructMessage with an XmlDocument, i.e.
// construct shape code
varXmlDoc = new System.Xml.XmlDocument();
varXmlDoc.LoadXml("<webSvcRequest2 xmlns=''><ParamB>" + msgWebSvcResp1.ParamA + "</ParamB></webSvcRequest2>");
msgWebSvcReq2 = varXmlDoc;
And similar code for producing the final output message. If you go this route, I'd advice creating some C# utility methods to actually store the strings/message templates.
For reasons outlined here I need to review a set values from they querystring or formdata before each request (so I can perform some authentication). The keys are the same each time and should be present in each request, however they will be located in the querystring for GET requests, and in the formdata for POST and others
As this is for authentication purposes, this needs to run before the request; At the moment I am using a MessageHandler.
I can work out whether I should be reading the querystring or formdata based on the method, and when it's a GET I can read the querystring OK using Request.GetQueryNameValuePairs(); however the problem is reading the formdata when it's a POST.
I can get the formdata using Request.Content.ReadAsFormDataAsync(), however formdata can only be read once, and when I read it here it is no longer available for the request (i.e. my controller actions get null models)
What is the most appropriate way to consistently and non-intrusively read querystring and/or formdata from a request before it gets to the request logic?
Regarding your question of which place would be better, in this case i believe the AuthorizationFilters to be better than a message handler, but either way i see that the problem is related to reading the body multiple times.
After doing "Request.Content.ReadAsFormDataAsync()" in your message handler, Can you try doing the following?
Stream requestBufferedStream = Request.Content.ReadAsStreamAsync().Result;
requestBufferedStream.Position = 0; //resetting to 0 as ReadAsFormDataAsync might have read the entire stream and position would be at the end of the stream causing no bytes to be read during parameter binding and you are seeing null values.
note: The ability of a request's content to be read single time only or multiple times depends on the host's buffer policy. By default, the host's buffer policy is set as always Buffered. In this case, you will be able to reset the position back to 0. However, if you explicitly make the policy to be Streamed, then you cannot reset back to 0.
What about using ActionFilterAtrributes?
this code worked well for me
public HttpResponseMessage AddEditCheck(Check check)
{
var request= ((System.Web.HttpContextWrapper)Request.Properties.ToList<KeyValuePair<string, object>>().First().Value).Request;
var i = request.Form["txtCheckDate"];
return Request.CreateResponse(HttpStatusCode.Ok);
}
In the latest ASP.NET MVC4 beta, how would you support conditional GET support via ETags? The ActionFilter would need to be able to complete the request to generate the ETag for the returned resource in order to compare to the If-None-Match header in the request. And then, regardless of whether the incoming ETag in the If-None-Match header was the same as the generated ETag, add the generated ETag to the ETag response header. But with ASP.NET MVC4, I have no idea where to begin. Any suggestions?
Personally, I'm not a fan of "framework magic" and prefer plain old code in the web methods, else we end up with something more akin to WCF, yuk.
So, within your Get web method, manually create the response like so:
var response = this.Request.CreateResponse(HttpStatusCode.OK, obj);
string hash = obj.ModifiedDate.GetHashCode().ToString();
response.Headers.ETag =
new EntityTagHeaderValue(String.Concat("\"", hash, "\""), true);
return response;
Please note that the ETag produced from the hash code of the timestamp is purely illustrative of a weak entity tagging system. It also shows the additional quotes required.
There is a ETagMessageHandler in the WebApiContrib which does what you need.
UPDATE
I have implemented RFC 2616's server side caching in WebApiContrib. Look for CachingHandler.
More info here.
More Update
This will be actively developed and expanded upon under CacheCow. This will include both client and server components. NuGet packages to be published soon are published now.
WebApiContrib's CachingHandler will still be maintained so any bugs or problems please let me know.
Luke Puplett's answer got me on the right track (+1), but note that you also have to read the ETag on the server side to avoid sending all the data with each request:
string hash = obj.ModifiedDate.GetHashCode().ToString();
var etag = new EntityTagHeaderValue(String.Concat("\"", hash, "\""), true);
if (Request.Headers.IfNoneMatch.Any(h => h.Equals(etag)))
{
return new HttpResponseMessage(HttpStatusCode.NotModified);
}
var response = this.Request.CreateResponse(HttpStatusCode.OK, obj);
response.Headers.ETag = etag;
return response;
It would also be a good idea to respect the If-Modified-Since header. See RFC 2616.
It seems this is what you are looking for (see section "Support for ETags"):
http://blogs.msdn.com/b/webdev/archive/2014/03/13/getting-started-with-asp-net-web-api-2-2-for-odata-v4-0.aspx
In case your model is stored deeper in domain and you are not able to apply the [ConcurrencyCheck] attribute, you can do that using the ODataModelBuilder:
ODataModelBuilder builder = new ODataConventionModelBuilder();
var myEntity = builder.EntitySet<MyEntity>("MyEntities");
myEntity.EntityType.Property(l => l.Version).ConcurrencyToken = true;
this will make it to add the "#odata.etag" property to a response body.