Develop Reference

Occasional response headers in C# HTTP Request

Request:
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
String responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
Console.WriteLine(responseString);
Response:
{"code":"SUCCESS","details":
{"created_time":"","id":"xxxx"},
"message":"uploaded",
"status":"success"}
HTTP/1.1 200 OK
Date: Wed, 18 Dec 2019 11:42:26 IST
Last-Modified: Wed, 18 Dec 2019 11:42:25 IST
Content-Type: application/json
Connection: Keep-Alive
Server: AWServer
Pragma: no-cache
Cache-Control: no-cache
Expires: 1
Whenever the above-mentioned C# request is executed, the response occasionally contains headers(HTTP/1.1 200 OK...), When I'm only trying to get the body part({"code"....} alone(response.GetResponseStream()). Is this the intended behavior?

Take a look at the basic article on http headers
HTTP headers let the client and the server pass additional information with an HTTP request or response. An HTTP header consists of its case-insensitive name followed by a colon (:), then by its value. Whitespace before the value is ignored.
Headers are additional information. I guess that since you left out the url and the whole creation of the Request and the url, this means that some responses have Headers and some not. That depends on the additional non-body information the api or web server wants to respond with.
It's in the control of the responder and not the receiver.
Don't ignore them: Some times interesting metadata come from Headers. It should not be data but information about it, like encoding, CORS info etc.
last modified header link
date header link

Is Dot Net HttpClient Unexpectedly Caching Responses?

I'm attempting to write a curl-like tool that demonstrates the effect of various HTTP caching headers on dot net's HttpClient class.
In my initial attempt I'm pointing the tool at one of my internal web services that does not specify any caching information in the response and examining the header of the response.
I expect to see that the request is re-sent each time and executed on the server, returning a new but identical set of content each time (for the purpose of this test, the content is static on the server). But, instead, each request after the first returns much more quickly than the first and includes a new header Age that was not present in the very first response. This indicates to me that the HttpClient in my command-line tool is returning the response from cache, not placing a new request.
Here is the first request with the response headers:
HTTP:>GET http://myserver:8058/path1/path2
Status 200 OK (OK in 00:00:00.3235905):
Date = Sat, 08 Jul 2017 15:55:22 GMT
Server = Microsoft-HTTPAPI/2.0
Content-Length = 150867
Content-Type = application/json; charset=utf-8
and here is the request from the same session of my curl tool, a little while later:
HTTP:>GET http://myserver:8058/path1/path2
Status 200 OK (OK in 00:00:00.0188433):
Date = Sat, 08 Jul 2017 15:55:22 GMT
Server = Microsoft-HTTPAPI/2.0
Age = 312
Content-Length = 150867
Content-Type = application/json; charset=utf-8
and finally, after I stop and start my program, here's another request from the new instance:
HTTP:>GET http://myserver:8058/path1/path2
Status 200 OK (OK in 00:00:00.0517271):
Date = Sat, 08 Jul 2017 15:55:22 GMT
Server = Microsoft-HTTPAPI/2.0
Age = 528
Content-Length = 150867
Content-Type = application/json; charset=utf-8
The last one I find even more difficult to understand as I was under the impression (from reading this: https://aspnetmonsters.com/2016/08/2016-08-27-httpclientwrong/) that caching is maintained per instance of HttpClient.
This seems to continue forever with Age increasing each request. The only way to get back to the original response is to use Internet Explorer and delete temporary internet files.
[Additional Info] After leaving my command line application open for a couple of hours I repeated the request and received a response identical to the original, without the Age header. So it appears that, if HttpClient was caching the response, that cache expired after a couple of hours.
Can anyone tell me if I'm correct that HttpClient is performing internal caching in this case, and if so, why it's doing so in the absence of any caching-related response headers and what policy it's using?

Microsoft Emotions API Get Recognition in Video Operation Result

How do I return the status and results from a video I posted to the emotions api using Get Recognition in Video Operation Result?
I can successfully run the Get Recognition in Video Operation Result using an operation id of a video I uploaded, but the response does not show the status of the video and the results from the emotions API but only shows the following:
StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.StreamContent,
Headers:{
Pragma: no-cache
apim-request-id: 010962c0-f907-4ba3-a7fd-564ddff7f97d
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
Cache-Control: no-cache
Date: Wed, 02 Nov 2016 02:33:16 GMT
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Content-Length: 16048
Content-Type: application/json; charset=utf-8 Expires: -1 }
I've tried using the same oid in the open api testing console
(https://dev.projectoxford.ai/docs/services/5639d931ca73072154c1ce89/operations/56f8d4471984551ec0a0984f/console)
and the response returns the status and the results from the emotions api.
I'm using the following code from the API reference:
var client = new HttpClient();
var queryString = HttpUtility.ParseQueryString(string.Empty);
// Request headers
client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", "{subscription key}");
var uri = "https://api.projectoxford.ai/emotion/v1.0/operations/{oid}?" + queryString;
var response = await client.GetAsync(uri);

Based on what you've pasted, it looks like you do have a response, 16048 bytes of JSON.
Since you're using C#, I think you'll save a lot of effort by using the client library, authored by members of the Cognitive Services team. If you use Visual Studio, you can simply pull down the NuGet package.
If you don't want to use the prebuilt library, you'll need to parse out the JSON yourself. The JSON will be in response.Content.

C# MVC RouteBase routing too many redirects

I have this custom routing system where i will get the paths, controllers, views and areas from my DB and set them according to the requested path.
My problem right now is that when i try to access one page it gives me the too many redirects response.
What happens in this area is:
User access page and fill a form;
Form is posted using AJAX and then a redirect is made from jquery;
User makes an appointment or generate a voucher;
If the user tries to return to the previous page by typing it on the browser( i don't have any button to that link ) he gets the too many redirects problem.
Since the code is kind of big i'm going to post it here: http://pastebin.com/yTdWKMp4
I only left out my DB logic.
What could be doing this ? I only could see the problem in this area but i don't know for sure it isn't happening in other areas.
EDIT
These are the headers from the requests
HTTP/1.1 302 Found
Cache-Control: private, no-store, max-age=1
Content-Type: text/html; charset=utf-8
Content-Encoding: gzip
Expires: Wed, 25 Nov 2015 19:01:23 GMT
Last-Modified: Wed, 25 Nov 2015 19:01:22 GMT
Etag: ""
Location: /teste-lp
Server: Microsoft-IIS/8.0
X-AspNetMvc-Version: 3.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
X-UA-Compatible: IE=Edge,chrome=1
Date: Wed, 25 Nov 2015 19:01:22 GMT
Content-Length: 115
HTTP/1.1 200 OK
Cache-Control: private, no-store, max-age=1
Content-Type: text/html; charset=utf-8
Content-Encoding: gzip
Expires: Wed, 25 Nov 2015 19:02:10 GMT
Last-Modified: Wed, 25 Nov 2015 19:02:09 GMT
Etag: ""
Server: Microsoft-IIS/8.0
X-AspNetMvc-Version: 3.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
X-UA-Compatible: IE=Edge,chrome=1
Date: Wed, 25 Nov 2015 19:02:12 GMT
Content-Length: 6852
EDIT 2
After much debugging and logging i found the beginning of the problem, it's related to a redirect i have when a certain session is null:
if (TempData["LeadID"] == null || Session["UnidadeCE"] == null)
{
Response.Redirect( HelperMethods.CreateLink( Request.RawUrl.TrimStart( '/' ).Split( '/' )[0] ) );
Response.End();
return null;
}
I have this verification at the appointment and voucher, if he tries to reload the page he is redirected to the form page. Now what is weird is, when he changes URL the RouteBase executes and tries to fetch the PageInfo( VirtualPath, Controller and View ) for that new URL and at the moment of my search for some reason i'm getting the page of appointment instead of the form one so i get back at the same page and the looping starts.
I have updated my pastebin with the filtering and DB Search, there are no repeated records in my DB. It looks like some sort of freaking cache but the var is local and there's no sharing.
EDIT 3
After some var watching ( i have nearly 6k routes ) i found that the problem lies between my route checking on the pastebin file on line 128, that pageList parameter is my list of all routes from the cache, i do a url search based and then i take the route that i need, on line 167 is where my problem is located. At that moment i have copied the content of the route i want into my freakingPage var (not so cool, i know) and then i change the values of Action and Controller but what also happens is the value changes on the pageList var and also at the Cache, line 203.
What could be causing this ?

After some research I found that my problem was related to the fact that I wasn't using Clone on the values that were coming from the cache. Since the .NET cache keeps a reference value when you get its value, it's necessary to implement ICloneable on the object you are getting from it.
Since I was only "putting" the value on another var and later editing this var I was in fact changing the original value on the cache... and with that I was getting a wrong return when I would hit the cache again.
In my case I was getting a redirect because of some Session verification that I was doing on my Controller, on the first time (freshly made cache) I would hit the correct page. But after I would try to re-enter the same page, I would get a different value from it.
To correct it I implemented ICloneable on my Model. I have also changed my example with the new approach if anyone also have this problem.
http://pastebin.com/yTdWKMp4

Would like to get http response results like Fiddler

I'm trying to get the same type of results that Fiddler gets when I launch a webpage from my app.
Below is the code I'm using and the results I'm getting. I've used google.com only as an example.
What do I need to modify in my code to get the results I want or do I need an entirely different approach?
Thanks for your help.
My code:
// create the HttpWebRequest object
HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create("http://www.google.com");
// get the response object which has the header info, using the GetResponse method
var objResults = objRequest.GetResponse();
// get the header count
int intCount = objResults.Headers.Count;
// loop through the results object
for (int i = 0; i < intCount; i++)
{
string strKey = objResults.Headers.GetKey(i);
string strValue = objResults.Headers.Get(i);
lblResults.Text += strKey + "<br />" + strValue + "</br /><br />";
}
My results:
Cache-Control
private, max-age=0
Content-Type
text/html; charset=ISO-8859-1
Date
Tue, 05 Jun 2012 17:40:38 GMT
Expires
-1
Set-Cookie
PREF=ID=526197b0260fd361:FF=0:TM=1338918038:LM=1338918038:S=gefqgwkuzuPJlO3G; expires=Thu, 05-Jun-2014 17:40:38 GMT; path=/; domain=.google.com,NID=60=CJbpzMe6uTKf58ty7rysqUFTW6GnsQHZ-Uat_cFf1AuayffFtJoFQSIwT5oSQKqQp5PSIYoYtBf_8oSGh_Xsk1YtE7Z834Qwn0A4Sw3ruVCA9v3f_UDYH4b4fAloFJbW; expires=Wed, 05-Dec-2012 17:40:38 GMT; path=/; domain=.google.com; HttpOnly
P3P
CP="This is not a P3P policy! See http://www.google.com/support/accounts/bin/answer.py?hl=en&answer=151657 for more info."
Server
gws
X-XSS-Protection
1; mode=block
X-Frame-Options
SAMEORIGIN
Transfer-Encoding
chunked
=========================
Fiddler results:
Result Protocol Host URL Body Caching Content-Type Process Comments Custom
1 304 HTTP www.rolandgarros.com /images/misc/weather/P8.gif 0 max-age=700 Expires: Tue, 05 Jun 2012 17:53:40 GMT image/gif firefox:5456
2 200 HTTP www.google.com / 23,697 private, max-age=0 Expires: -1 text/html; charset=UTF-8 chrome:2324
3 304 HTTP www.rolandgarros.com /images/misc/weather/P9.gif 0 max-age=700 Expires: Tue, 05 Jun 2012 17:53:57 GMT image/gif firefox:5456
4 200 HTTP Tunnel to translate.googleapis.com:443 0 chrome:2324
5 200 HTTP www.google.com

The difference is Fiddler is actually recording an entire session, not just a single HTTP request.
If a user loads Google.com, the response is typically an HTML document which contains images, script files, CSS files, etc. Your browser will then initiate a new HTTP request for each one of those resources. With Fiddler running, it tracks each of those HTTP requests and spits out the result code and other information about the session.
With your C# code above, you're only initiating a single HTTP request, thus you only have information about a single result.
You'd probably be better off writing a browser plugin. Otherwise, you'd have to parse the HTML response and load other resources from that document as well.
If you do need to do this with C# code, you could probably parse the document with the HTML Agility Pack and then look for other resources within the HTML to simulate a browser. There's also embedded browsers, such as Awesomium, that might be helpful.

You are not asking for the same information that Fiddler is displaying. Fiddler shows the HTTP Status code, the host and URI and (it appears, from your example) the Content Length, Content Type and Cache status.
For many of these you will have to peek in to the response headers.