nancyfx posting json - Nancy.DynamicDictionary is empty - asp.net

I'm just starting to play with NancyFx to compare it with the .net MVC WebAPI stuff and I've hit an issue straight away. As I understand it Nancy should handle serialization straight out of the box. But I can't seem to get it working.
I have a Nancy Module that looks like this:
public class HelloWorld : NancyModule
{
public HelloWorld()
{
Post["/"] = parameters =>
{
var myFieldValue = parameters.myField;
return HttpStatusCode.OK;
};
}
}
And I post to it using Fiddler like this:
Headers:
User-Agent: Fiddler
Content-Type: application/json
Host: localhost:3141
Content-Length: 24
Request-Body:
{"myField" : "profit"}
However when the parameters object is empty (and so, therefore is the myFieldValue object).
I'm sure I've missed something really obvious, but I don't know what!

Parameters are for captures in the url (e.g. /foo/{bar} would capture a bar variable in parameters. If you are posting JSON you should use the model binder (var foo =this.Bind();
I would recommend taking a look at the docs too.. All of this is covered there :-)

For posting data you have to use model binding.
Unfortunately, model binding to dynamic is not supported and you have to create request classes. There is a proposed workaround , but I didn't use it myself.
If you don't want to define class for particular request and use model binding, then you can use power of dynamic with json.net.
Example:
public AuthTokenModule (IAuthService authService, UserMapper mapper) : base ("api/v1/authToken")
{
Post ["/login"] = x => {
dynamic request = JsonConvert.DeserializeObject (Request.Body.AsString ());
var user = mapper.ValidateUser ((string)request.email, (string)request.password);

Related

Angular2 HTTP Post ASP.NET MVC Web API

How do you properly create a Web API POST of complex object or multiple parameters using Angular2?
I have a service component in Angular2 as seen below:
public signin(inputEmail: string, inputPassword: string): Observable<Response> {
return this.http.post('/api/account/signin', JSON.stringify({ Email: inputEmail, Password: inputPassword}), this.options);
}
The targeted web api is seen below:
[HttpPost]
[Route("signin")]
public async Task<IActionResult> Signin(string email, string password)
{
....
}
This does not work because I need to convert the parameters of the web api into a single POCO class entity with Email and Password properties and put the [FromBody] attribute: Signin([FromBody] Credential credential)
Without using [FromURI] (POST requests with query strings?), how can I make POSTs of multiple parameters or complex objects without converting these parameters into a single POCO class?
Because what if I have numerous Web API POST actions with parameters like (string sensitiveInfo1, string name, int sensitiveInfo2) or (ClassifiedInfo info, string sensitiveInfo1, string sensitiveInfo2), do I need to convert them all to POCO classes and always use [FromBody]?
PS.
I was using RestangularJS before and it can posts anything (mulitple primitive objects and complex objects) without my Web API actions having [FromBody] attributes. Will about to investigate how RestangularJS do it.
Without using [FromURI] (POST requests with query strings?), how can I make POSTs of multiple parameters or complex objects without converting these parameters into a single POCO class?
I know its not what you want to hear but out of the box this is not possible. It is not a limitation of the browser code that is making the request. This means it does not matter if you are using Angular, JQuery, straight JavaScript, or even RestangularJS. This is a limitation (I use that word loosely as I am sure this is by design) of Web API (any version). Here is the documentation on this design: Parameter Binding in ASP.NET Web API by Mike Wasson.
At most one parameter is allowed to read from the message body. So this will not work:
// Caution: Will not work!
public HttpResponseMessage Post([FromBody] int id, [FromBody] string name) { ... }
So the question becomes, what are your options?
Create a model
This is the thing you were trying to avoid but I list it first because this is how Web API was intended to behave. I have not yet heard a compelling reason not to do this. This approach allows you to extend your model easily without having to change the method signature. It also allows for model validation on the model itself. Personally I really like this approach.
public class SignInModel{
public string Email {get;set;}
public string Password {get;set;}
}
[HttpPost]
[Route("signin")]
public async Task<IActionResult> Signin(SignInModel signInModel)
{
// ....
}
I did not repeat your existing JavaScript code because what you have works as is with the above web api code
URL
Again, what you were trying to avoid. This does make what you want possible with the limitation that you have to pass these parameters using the Query string on the URL. The JavaScript would change but the signature you had on the Web API method would not.
public signin(inputEmail: string, inputPassword: string): Observable<Response> {
return this.http.post('/api/account/signin/?email=inputEmail&password=inputPassword', null, this.options);
}
I did not repeat your existing Web API code because what you have works as is with the above web JavaScript code (by default FromUri is assumed I believe)
Custom Model Binder
See Passing multiple POST parameters to Web API Controller Methods by Rick Strahl. This option allows you to create a custom model binder that could do what you are asking. It is a whole bunch of extra code though for, IMHO, not much benefit. Maybe there are situations where it would be useful although I really cannot think of any off the top of my head.
Dynamic
Finally you could also pass in a dynamic object as the parameter of your Web API. This is essentially the same as receiving the JSON as a string and making your Controller code responsible for the deserialization of content. Again, I believe that this would make your code worse in most situations as you have to implement custom validation and type checks. This answer was proposed previously on SO by Bes Ley. Again, maybe there are situations where it would be useful although I really cannot think of any off the top of my head.
If you call Web API 2.2 post method from Angular 2 type script, dont forget to add following header content and parameter object.
let headers = new Headers({ 'Content-Type': 'application/x-www-form-urlencoded' });
var params = new URLSearchParams();
params.set('userid', '102');
params.set('username', 'foo');
return this._http.post('http://localhost:6579/api/PostUser', params.toString(), { headers: headers }).map(res => res.json());
Perhaps you should post with options:
{
headers: new Headers({
'Content-Type': 'application/x-www-form-urlencoded'
})
}
and encode data like
jQuery.param({user:'bla', password: 'bla'});
WebAPI does not provide this out of the box. If you try to get understanding of web API bindings, you might be able to figure out why.
I think this article might help.
The generic rules are:
– simple, string-convertible parameters (value types, strings, Guids, DateTimes and so on) are by default read from URI
– complex types are by default read from the body
– collections of simple parameters are by default read from the body too
– you cannot compose a single model based on input from both URI and request body, it has to be one or the other
I have fixed the issue of Angular2 HTTP Post ASP.NET MVC Web API
let headers = new Headers();
headers.append('Content-Type', 'application/x-www-form-urlencoded; charset=utf-8');
let params: URLSearchParams = new URLSearchParams();
params.set('value', '2');
let options = new RequestOptions({
headers: headers//,
//search: params
});
let content = new URLSearchParams();
content.set('StudentName', 'Inderjit Singh';
content.set('Mobile', '+919041165398');
content.set('Nationality', 'Indian');
content.set('AdmissionNo', '6');
content.set('SectionCode', '1');
content.set('Gender', 'Male');
content.set('RegNo', '18585');
content.set('ClassCode', '1');
this.http.post('YOUR_URL', content.toString(), { headers: headers }).map((res: Response) => { console.log("data is==>" + res.text()); }).subscribe();
WebApi will be able to deserialize your Credential object provided the JSON object has the same field names (I am not sure about case so you may be right here). You seem to be missing the headers from the post call in your Angular2 component.
Can you check the Content-Type using Chrome Debugger or Fiddler? It should be application/json.
Try this, passing a complex class object into a single data parameter.
var SearchQuery = function () {
this.Alphabet = null;
this.Search = false;
this.Keyword = null;
this.RegionList = null;
};
var para = new SearchQuery();
{ data: JSON.stringify(para) } - Post Data
you can receive it using a JObject in your API controller and deserialize it as according to your classes.

How should I send params to a Asp.Net WebAPI 2.1 data query method?

I have been coding like this. Sometimes there are one, two, three or more parameters:
$http({ url: '/api/Topic/Retrieve',
method: "GET",
params: {
subjectId: sub
}
})
The result is like this with all the query params as part of the query string:
GET /api/Topic/Retrieve?subjectId=1 HTTP/1.1
My WebAPI controllers look like this:
[HttpGet]
public async Task<IHttpActionResult> Retrieve(int subjectId)
{
var topics = await db.Topics
.Include(q => q.SubTopics)
.Where(q => q.SubjectId == subjectId)
.ToListAsync();
return Ok(topics);
}
This works but now I am setting up Asp.Net attribute route decorations and there is no simple way to do that when I use the query string to pass data. So should I do something like the following if there are one, two or three parameters?
GET /api/Topic/1 HTTP/1.1
GET /api/Topic/1/2 HTTP/1.1
GET /api/Topic/1/2/abcd HTTP/1.1
Or alternatively should I code the parameters in the body and then use: [FromBody] before the parameters to the Asp.Net method ? One more question. If I code the parameters in the body then how would I do that with AngularJS. Should I use the data param in the $http call ?
You should be able to define the method access name for your Retrieve method by
[HttpGet("Retrieve")]
and continue using query parameters like you were originally without messing with the route.
(Similar to this answer: Web API 2 / MVC 5 : Attribute Routing passing parameters as querystring to target different actions on same controller)

Windows Azure access POST data

Ok, so I can't seem to find decent Windows Azure examples. I have a simple hello world application that's based on this tutorial. I want to have custom output instead of JSON or XML. So I created my interface like:
[ServiceContract]
public interface IService
{
[OperationContract]
[WebInvoke(UriTemplate = "session/create", Method = "POST")]
string createSession();
}
public class MyService : IService
{
public string createSession()
{
// get access to POST data here: user, pass
string sessionid = Session.Create(user, pass);
return "sessionid=" + sessionid;
}
}
For the life of me, I can't seem to figure out how to access the POST data. Please help. Thanks!
If you have an HttpContext there may be a Request object that would have the form data. I'm basing part of this off the ASP.Net tag on this question, so if that is incorrect then there may be the need to handle this another way but it looks a lot like a web service to my mind.
EDIT: HttpRequest is the class that has the Form property that should be where the POST data is stored if this is an HTTP request. This is part of System.Web so it should be ready to be used pretty easily, as I recall.
Sample code showing the Request.Form property:
int loop1;
NameValueCollection coll;
//Load Form variables into NameValueCollection variable.
coll=Request.Form;
// Get names of all forms into a string array.
String[] arr1 = coll.AllKeys;
for (loop1 = 0; loop1 < arr1.Length; loop1++)
{
Response.Write("Form: " + arr1[loop1] + "<br>");
}
This presumed there was an HttpRequest instance around.
WCF Simplified Part 4: Comparing the Request/Reply and One-Way Patterns passes in a parameter so that your "createSession" method would have to take in those strings it would appear. I'm used to the ASP.Net world where there are some built-in objects like Request, Response, Server, Application and Session.
Yes, if you did try changing the method signature as there are ways to pass in parameters in that last example I linked though I don't know if that would work in your case or not.

OpenRasta unit testing

I’m about to start work on an OpenRasta project (an xml over http web service). OpenRasta looks great but unfortunately worked examples seem few and far between on the internet. Looking at the test side of the project, if my handlers are returning strongly typed objects (not OperationResult), i.e.:
public class PersonHandler
...
public Person Get(int id)
{
...
How can I test for http status codes? (For example if the handler throws an uncaught exception). I’m not sure what level the tests pitch in at, and what needs mocking (using moq btw)
Any help appreciated, particularly coded examples!
I faced the same problem, and ended up writing my tests as integration tests at a much higher level, actually making real REST/HTTP calls through a simple HttpWebRequest client. This allowed me to check the HTTP response headers / status codes and double-check the JSON/XML serialization from the client's perspective, which was just as important as whether or not the operations succeeded.
I started by returning OperationResult from all my handlers, and used these to wrap the strongly-typed objects. My handlers all inherit from a base class with a few helper methods that make it easier to return a custom error with a user-friendly error message. The more I coded this up, the more my handlers resembled a ASP.NET MVC controller. e.g.:
public OperationResult GetById(int id)
{
try
{
// do stuff here
return OKResult( // some strongly-typed resource );
}
catch(SomeException ex)
{
return BadRequestResult(SomeErrorCode, ex.Message);
}
}
Then in the test client, it's pretty easy to just check the HTTP status code. Obviously this doesn't help much with mocking. I'm not sure what the best solution is, in fact I've favorited this question in the hope that someone answers it better than I can - but this has worked pretty well for me so far.
The handler is just a class--ideally with minimal dependencies--so your unit tests can just test the isolated logic in the class.
If you want to test for status codes, I recommend (based on very little experience!) using OpenRasta self-hosting.
Here's a test (somewhat changed) that I wrote recently:
[TestMethod]
public void POST_with_inaccurate_contentLength_returns_405()
{
var resource = GetResource();
IRequest request = new InMemoryRequest
{
HttpMethod = "POST",
Uri = new Uri("http://localhost/Resource"),
};
request.Headers.ContentLength = 16; //wrong!
request.Entity.Stream.Write(resource.Content, 0, resource.Content.Length);
var response = _host.ProcessRequest(request);
Assert.AreEqual(405, response.StatusCode);
}
I should add that the host is set up in the TestInitialize method as such:
_host = new InMemoryHost(new Configuration());
_host.Resolver.AddDependencyInstance(typeof(IFileResourceRepository), _repository, DependencyLifetime.Singleton);
...and is cleaned up in the TestCleanup method.

Parse Accept Header

Does anyone have any suggestions (or a regular expression) for parsing the HTTP Accept header?
I am trying to do some content-type negotiation in ASP.NET MVC. There doesn't seem to be a built in way (which is fine, because there are a lot of schools of thought here), but the parsing is not entirely trivial and I would rather not re-invent the wheel if someone has already done it well and is willing to share.
Have you seen this article? It gives a pretty comprehensive implementation for parsing the Accept header and subsequently doing something useful with it.
As of .NET 4.5 (I think—Microsoft have made info on framework versions < 4.5 rather obscure these days), you can use one of the the built in parsers from System.Net.Http.Headers:
public IOrderedEnumerable<MediaTypeWithQualityHeaderValue> GetMediaTypes(string headerValue) =>
headerValue?.Split(',')
.Select(MediaTypeWithQualityHeaderValue.Parse)
.OrderByDescending(mt => mt.Quality.GetValueOrDefault(1));
Then you can do something like this:
var headerValue = "application/json, text/javascript, */*; q=0.01";
var mediaTypes = GetMediaTypes(headerValue);
Giving you a nice list of all the media types, where the preferred option is the first item. Here's a LINQPad Dump of the mediaTypes result from the example:
Hat tip to this answer, for getting me on the right track.
I've written a parser in PHP. It's not complex, but it will give you an array of mime types in order of preference.
Found another implementation in php here
After reading the xml.com article I decided to not write a function for the Accept header myself ;)
Fortunately the article points to a good library: https://code.google.com/p/mimeparse/ - in my case I need it as a Node.js module: https://github.com/kriskowal/mimeparse
Building on https://stackoverflow.com/a/49011308/275501 from https://stackoverflow.com/users/43140/mark-bell above:
public class MyController : Controller
{
[HttpGet]
[Route("/test")]
public ActionResult Index() {
// does this request accept HTML?
var acceptsHTML = IsAcceptable("text/html");
var model = FetchViewModel();
return acceptsHTML ? (ActionResult) View(model) : Ok(model);
}
private bool IsAcceptable(string mediaType) =>
Request.Headers["Accept"].Any(headerValue =>
!string.IsNullOrWhiteSpace(headerValue) &&
headerValue.Split(",").Any(segment => MediaTypeHeaderValue.Parse(segment).MediaType == mediaType));
private object FetchViewModel() {
return new { Description = "To be completed" };
}
}
The RFC is quite complex. If the regex where to follow these rules to the letter, it would become several lines long.
If you already have the Accept-header, and ignore the quotes and the parameters, you could do something like this to match each pair:
/([^()<>#,;:\\"\/[\]?={} \t]+)\/([^()<>#,;:\\"\/[\]?={} \t]+)/
* is included in the character class, so it does not need any special case in the regex.

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