I have a Web Api service that retrieves data from another service, which returns Json. I don't want to do anything to the response, I just want to return it directly to the client.
Since the response is a string, if I simply return the response, it contains escape characters and messy formatting. If I convert the response in to an object, the WebApi will use Json.Net to automatically format the response correctly.
public IHttpActionResult GetServices()
{
var data = _dataService.Get(); //retrieves data from a service
var result = JsonConvert.DeserializeObject(data); //convert to object
return Ok(result);
}
What I would like is to either A: Be able to return the exact string response from the service, without any of the escape characters and with the proper formatting, or B: Set a global settings that will automatically Deserialize the response so that the Web Api can handle it the way I am doing it already.
On Startup I am setting some values that describe how formatting should be handled, but apparently these aren't correct for what im trying to do.
HttpConfiguration configuration = new HttpConfiguration();
var settings = configuration.Formatters.JsonFormatter.SerializerSettings;
settings.Formatting = Formatting.Indented;
settings.ContractResolver = new DefaultContractResolver();
Do I need to create a custom ContractResolver or something? Is there one that already handles this for me?
Thanks
If you want to just pass through the json (Option A), you can do this
public IHttpActionResult GetServices() {
var json = _dataService.Get(); //retrieves data from a service
HttpContent content = new System.Net.Http.StringContent(json, Encoding.UTF8, "application/json");
var response = Request.CreateResponse(HttpStatusCode.OK);
response.Content = content;
return ResponseMessage(response);
}
Related
I need to create a Web API "wrapper" that is consumed by a client, but in this Web API Service, I actually need to create a POST request to a different REST API service that is running on the same IIS server that does some work and returns StringContent that I pass back to the client via a JSON HttpResponse. Is this possible? Instead of the client making direct calls to the actual REST API and returning data they don't need/want, they would call my Web API service and I would only return them the required data. I know this was done in the old SOAP WSDL model.
If I need the client to pass in a couple parameters that are required for my POST request, would I be having the client use a GET or POST request?
This is an sample code i used call API inside another API using POST method.
using (var client = new HttpClient())
{
string query;
using (var content = new FormUrlEncodedContent(new Dictionary<string, string>()
{
{"username", username},
{"password", password}
}))
{
query = content.ReadAsStringAsync().Result;
}
var model = new{
username = txtUsername.Text,
password = txtPassword.Text
};
var json = JsonConvert.SerializeObject(model);
var user = new StringContent(json, Encoding.UTF8, "application/json");
using (var response = await client.PostAsync(#"http://localhost/dataagent/api/user/authenticate", user))
{
if (response.IsSuccessStatusCode)
{
var result = await response.Content.ReadAsStringAsync();
// handle result here
}
}
}
I have an endpoint that needs to accept a file upload and also some other information from the client request. With the following code I can upload the file successfully but can't seem to figure out how to read the other info.
I make a test request from Postman with the following form data:
image -- myimage.jpg -- of type File
email -- a#b.com -- of type Text
The backend code looks like this:
[HttpPost]
public async Task<HttpResponseMessage> SharePhoto()
{
try
{
var provider = new MultipartMemoryStreamProvider();
var data = await Request.Content.ReadAsMultipartAsync(provider);
// this is how I get the image which I am succesfully passing to EmailService
var item = (StreamContent)provider.Contents[0];
using (var stream = new MemoryStream())
{
await item.CopyToAsync(stream);
String emailAddress;
EmailService.SendSharedPhoto(emailAddress, stream);
return Request.CreateResponse();
}
}
catch
{
// do stuff
}
}
In this example I am able to access provider.Contents[1] but can't seem to be able to get the value from it into emailAddress. I'm thinking it may be possible to use the same trick as the await item.CopyToASync(stream) from the image upload, but I'm hoping I can get a simpler solution to that. Any ideas?
I just barely answered a very similar question to this yesterday. See my answer here complete with sample controller code.
The method I ended up using is:
If the form elements are strings (and it worked for me since the mobiel frontend took responsability for input data) you can do this:
var streamContent = (StreamContent)provider.Contents[1];
var memStream = new MemoryStream();
await streamContent.CopyToAsync(memStream);
var actualString = Encoding.UTF8.GetString(x.ToArray());
If however the field needs to represent a collection of items, like for example the email list: ["a#b.com", "x#c.com"], etc a JavaScriptSerializer can be user, like so:
var streamContent = (StreamContent)provider.Contents[1];
var emailAddresses = await str.ReadAsStringAsync();
var jsSerializer = new JavaScriptSerializer();
var deserializedData = jsSerializer.Deserialize<string[]>(emailAddresses);
Note that this is nowhere near safe, though it is few lines of code and happens to work.
I have an http module where I'm adding a response filter below for compression. This works for all API calls except for 1, the call to MetaData. If I remove the [BreezeController] decoration it works fine. I think it has to do with action filter attribute that converts the string return type into an HttpResponse return type with string content.
The error I'm getting is " Exception message: The stream state of the underlying compression routine is inconsistent."
I've done some testing where a method thats defined to return an HttpResponse works fine. So I think its the scenario where the method is defined to return string, and then the action filter changes it to HttpResponse at runtime.
Any ideas how I can get this to work?
Here's the response filter being added in BeginRequest:
HttpApplication app = (HttpApplication)sender;
// Check the header to see if it can accept compressed output
string encodings = app.Request.Headers.Get("Accept-Encoding");
if (encodings == null)
return;
Stream s = app.Response.Filter;
encodings = encodings.ToLower();
if (encodings.Contains("gzip"))
{
app.Response.Filter = new GZipStream(s, CompressionMode.Compress);
app.Response.AppendHeader("Content-Encoding", "gzip");
}
Don't know the specifics of what you're doing but I know that the [BreezeController] attribute strips out filters and adds back just the ones that breeze wants.
One approach might be to define a separate controller (ModelMetadataController) that only serves the metadata. This controller doesn't have the [BreezeController] attribute; it's a plain old Web API controller.
Then you create a "Breeze controller" (ModelController) with all of the usual methods except the Metadata method.
You call the metadata controller from the client during app launch via MetadataStore.fetchMetadata just to get metadata.
Once you have populated a metadataStore in this fashion, you use it in your EntityManager which sends query and save requests to the "real" Web API data controller.
The client code might look something like this:
var ds = new breeze.DataService({
serviceName: 'breeze/Model' // the breeze query & save controller
});
var ms = new MetadataStore({
namingConvention: breeze.NamingConvention.camelCase, // assuming that's what you want
});
ms.addDataService(ds); // associate the metadata-to-come with the "real" dataService
var manager = new breeze.EntityManager({
dataService: ds,
metadataStore: ms
});
// the fun bit: fetch the metadata from a different controller
var promise = ms.fetchMetadata('breeze/ModelMetadata') // the metadata-only controller!
return promise; // wait on it appropriately
I want to do an integration test for the below action.
How can I pass my requestDto object in the integration test?
Neither the GetAsync nor SendAsync method has an overload parameter to pass a custom object to the server.
[Route("{startDate:datetime}")]
[HttpGet]
public HttpResponseMessage Get(DateTime startDate, [FromBody]LessonplannerGetRequest request)
{
request.StartDate = startDate;
var lessonplannerResponse = _service.GetPeriodsByWeekStartDate(request);
return Request.CreateResponse<LessonplannerResponse>(HttpStatusCode.OK, lessonplannerResponse);
}
[Test]
public void Get_Lessons_By_Date()
{
// Arrange
var request = new HttpRequestMessage(HttpMethod.Get, _server.BaseAddress + "/api/lessonplanner/2014-01-14");
var myRequestDto = new LessonplannerGetRequest();
// Act => QUESTION: HOW do I pass the myRequestDto ???
var response = _client.SendAsync(request, new CancellationToken()).Result;
// Assert
Assert.That(response.StatusCode == HttpStatusCode.OK);
}
UPDATE
As Darrel Miller said:"Technically HTTP says you can send a body, it just says the body doesn't mean anything and cannot be used. HttpClient won't let you send one."
I post here my integration test with HttpClient doing a Get request with complex type + FromBody:
// Arrange
var request = new HttpRequestMessage(HttpMethod.Get, _server.BaseAddress + "/api/lessonplanner/2014-01-14");
var myRequestDto = new LessonplannerGetRequest{ FirstDayOfWeek = DayOfWeek.Sunday, SchoolyearId = 1, StartDate = DateTime.Today};
request.Content = new ObjectContent<LessonplannerGetRequest>(myRequestDto, new JsonMediaTypeFormatter());
request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
_client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
// Act
var response = _client.SendAsync(request, new CancellationToken()).Result;
// Assert
Assert.That(response.StatusCode == HttpStatusCode.OK);
Of course is this is not the Http way some might consider doing it differentlly sending complex type via FromUri/query string.
HTML specifications says you cannot send a GET with a body.
HTTP specs allows it.
WebAPI allows it, because it is a service/REST and implements HTTP but not HTML, but many clients and browser won't allow it because they implement both specs and try to be strict.
As for the specifications (RFC1866, page 46; HTML 4.x section 17.13.3) itself, it states:
If the method is "get" and the action is an HTTP URI, the user agent takes the value of action, appends a `?' to it, then appends the form data set, encoded using the "application/x-www-form-urlencoded" content type.
(e.g. if you do a <form> with GET, it will parse all the form params and set them in the query string ?a=b).
In term of pure HTTP and in the context of REST services, nothing prevents that behavior, but not all clients will be able to handle it. It's mostly a best-practice advise when it comes to REST/WebAPI to not handle body data from HttpGet, only URI data (the opposite, POST /action?filter=all is usually tolerated for metadata/action qualifiers, but that's another discussion).
So yeah, it's at your own risk, even if used only internally. As not all clients handle it (e.g. HttpRequestMessage), so you might run into trouble like you have.
You should NOT pass a GET body with HTTPClient.
I created some web apis and when an error happens the api returns HttpResponseMessage that is created with CreateErrorResponse message. Something like this:
return Request.CreateErrorResponse(
HttpStatusCode.NotFound, "Failed to find customer.");
My problem is that I cannot figure out how to retrieve the message (in this case "Failed to find customer.") in consumer application.
Here's a sample of the consumer:
private static void GetCustomer()
{
var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
string data =
"{\"LastName\": \"Test\", \"FirstName\": \"Test\"";
var content = new StringContent(data, Encoding.UTF8, "application/json");
var httpResponseMessage =
client.PostAsync(
new Uri("http://localhost:55202/api/Customer/Find"),
content).Result;
if (httpResponseMessage.IsSuccessStatusCode)
{
var cust = httpResponseMessage.Content.
ReadAsAsync<IEnumerable<CustomerMobil>>().Result;
}
}
Any help is greatly appreciated.
Make sure you set the accept and or content type appropriately (possible source of 500 errors on parsing the request content):
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
content.Headers.ContentType = new MediaTypeWithQualityHeaderValue("application/json");
Then you could just do:
var errorMessage = response.Content.ReadAsStringAsync().Result;
That's all on the client of course. WebApi should handle the formatting of the content appropriately based on the accept and/or content type. Curious, you might also be able to throw new HttpResponseException("Failed to find customer.", HttpStatusCode.NotFound);
One way to get the message is to do:
((ObjectContent)httpResponseMessage.Content).Value
This will give you a dictionary that contains also the Message.
UPDATE
Refer to the official page:
http://msdn.microsoft.com/en-us/library/jj127065(v=vs.108).aspx
You have to vary the way you're reading the successful response and the error response as one is obviously in your case StreamContent, and the other should be ObjectContent.
UPDATE 2
Have you tried doing it this way ?
if (httpResponseMessage.IsSuccessStatusCode)
{
var cust = httpResponseMessage.Content.
ReadAsAsync<IEnumerable<CustomerMobil>>().Result;
}
else
{
var content = httpResponseMessage.Content as ObjectContent;
if (content != null)
{
// do something with the content
var error = content.Value;
}
else
{
Console.WriteLine("content was of type ", (httpResponseMessage.Content).GetType());
}
}
FINAL UPDATE (hopefully...)
OK, now I understand it - just try doing this instead:
httpResponseMessage.Content.ReadAsAsync<HttpError>().Result;
This is an option to get the message from the error response that avoids making an ...Async().Result() type of call.
((HttpError)((ObjectContent<HttpError>)response.Content).Value).Message
You should make sure that response.Content is of type ObjectContent<HttpError> first though.
It should be in HttpResponseMessage.ReasonPhrase. If that sounds like a bit of a strange name, it's just because that is the way it is named in the HTTP specification http://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html
OK this is hilarious, but using QuickWatch I came up with this elegant solution:
(new System.Collections.Generic.Mscorlib_DictionaryDebugView(((System.Web.Http.HttpError)(((System.Net.Http.ObjectContent)(httpResponseMessage.Content)).Value)))).Items[0].Value
That is super readable!