I am curious why the ApiController handles default parameter values on actions differently than a 'regular' Controller.
This code works just fine, request to /Test means page gets value 1
public class TestController : Controller
{
public ActionResult Index(int page = 1)
{
return View(page);
}
}
This code doesn't work when a request is made to /api/Values. It fails with:
"The parameters dictionary contains a null entry for parameter 'page' of non-nullable type 'System.Int32' for method 'System.Collections.Generic.IEnumerable`1[System.String] Get(Int32)' in 'MvcApplication1.Controllers.Controllers.ValuesController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter."
public class ValuesController : ApiController
{
public IEnumerable<string> Get(int page = 1)
{
return new string[] { page.ToString() };
}
}
Any hints on why this is?
Try adding the [FromUri] or [FromForm] parameter attribute.
public class ValuesController : ApiController
{
public IEnumerable<string> Get([FromUri]int page = 1)
{
return new string[] { page.ToString() };
}
}
Mike Stall has two good posts about parameter binding in Webapi which does not work as it does in ASP MVC. The big problem to get used to is that you can only read the request body once in your pipeline. So if you need to read more than 1 complex object as a parameter, you probably need to resort to ModelBinding by parameter. I had a problem similar to yours when I was reading the content body earlier in the pipeline for logging purposes and did not realize about the read once restriction above and had to solve with my own custom model binder.
Explains model binding at http://blogs.msdn.com/b/jmstall/archive/2012/04/16/how-webapi-does-parameter-binding.aspx and then suggests a way to make WebAPI model binding more like ASP MVC http://blogs.msdn.com/b/jmstall/archive/2012/04/18/mvc-style-parameter-binding-for-webapi.aspx
Try defining as Nullable<T>:
public class ValuesController : ApiController
{
public IEnumerable<string> Get(int? page = 1)
{
return new string[] { page.ToString() };
}
}
Related
I'm migrating some old ASP.NET MVC 5 code to .NET 6.0 and having some trouble with an AuthorizationFilter that, within its OnAuthorization implementation, accesses the decorated method's controller class instance, like this:
// Get the decorated method's name
string actionName = filterContext.ActionDescriptor.ActionName;
// Get the controller instance and then, its type
Type controllerType = filterContext.Controller.GetType();
I just can´t see how I would get the controller instance (or event the method's name) from the AuthorizationFilterContext available in .NET 6.0. Any help?
create new class
public class LogEntry : IAuthorizationFilter
{
public void OnAuthorization(AuthorizationFilterContext context)
{
var controllerActionDescriptor = context.ActionDescriptor as
ControllerActionDescriptor;
string controllerName =
controllerActionDescriptor?.ControllerName;
string actionName =
controllerActionDescriptor?.ActionName;
}
}
In Program.cs register LogEntry class
builder.Services.AddScoped<LogEntry>();
on controller action method
[ServiceFilter(typeof(LogEntry))]
public IActionResult Index()
{
return View();
}
I'm developing an Asp.Net Core API.
My controller declaration
[ApiController]
public class BarController : Controller
{
...
}
My endpoint looks like this
[HttpPost, Route("bars")]
public async Task<ActionResult> DoAsync(
[FromBody] UpdateBars command)
{
// Do something with the command
return Ok(result);
}
The command looks like this
public class UpdateBars
{
[Required]
public IEnumerable<string> Ids { get; set; }
// ... more properties
}
Compatibility level is set to 2.1
public IServiceProvider ConfigureSharedServices(IServiceCollection services)
{
// ...
services.AddMvc()
.AddControllersAsServices()
.SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
// ...
}
Old question: I'd expect this to return a 400 bad request with a missing Ids parameter, but it fails to return the binding error.
What am I doing wrong?
Updated question: I'd expect this to return a 400 bad request with a missing or empty Ids parameter. The response is as expected if the parameter is missing (null), but returns 200 ok if it is an empty collection.
Is it possible to change something so that I get a bad request when the parameter is present but empty?
You probably didn't put a [ApiController] attribute on your controller.
By default the validation is not 'automatic'.
If you don't want to put that attribute on your controller, you will have to validate the model yourself, in following way:
[HttpPost, Route("bars")]
public async Task<ActionResult> DoAsync(
[FromBody] UpdateBars command)
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
// Do something with the command
return Ok(result);
}
You have more controll in that way, but if you just need to return a BadRequest with the model state, it will happen automatically if you put the [ApiController] on the controller.
Also in that case it will mark all action parameters as [FromBody], so putting that attribute on params is not needed
You should add the [ApiController] attribute. In that case, an automatic HTTP 400 response containing error details is returned when model state is invalid. For more information, see Automatic HTTP 400 responses. Automatic HTTP 400 responses.
I am attempting to return a CreatedAtAction() result from within an ApiController "NotUnitsController" which indicates a route on a separate ApiController "UnitsController".
Everything works as expected until generating the CreatedAtAction() response. I am receiving the error:
System.InvalidOperationException: No route matches the supplied values.
I am not sure what I am missing. I have tried to remedy the issue with the following:
Verified the spelling of the route parameters on both controllers
Attempted to provide a route name to the [HttpGet] in the UnitsController & reference that name from the NotUnitsController.
Added a / to the [HttpGet("/{unitKey}")] route as suggested in this answer.
The v1 portion of the routes are hard-coded. I found that it could be an issue with dynamic route versioning on this GitHub issue.
I am also able to perform GET requests against the UnitsController endpoint. Only the CreatedAtAction() response is failing.
Here are snippets of the two controllers in question.
NotUnitsController:
[ApiController]
[Route("v1/not-units/{notUnitsKey:guid}/units")]
public class NotUnitsController : ControllerBase
{
[HttpPost]
public async Task<IActionResult> Post(Guid notUnitsKey, Input unitInput)
{
// TODO: Create Unit
var unitKey = Guid.NewGuid();
return CreatedAtAction(actionName: nameof(UnitsController.Get),
controllerName: nameof(UnitsController),
routeValues: new { unitKey },
value: new { unitKey });
}
}
UnitsController:
[ApiController]
[Route("v1/units")]
public class UnitsController : ControllerBase
{
[HttpGet("{unitKey:guid}")]
public async Task<IActionResult> Post(Guid unitKey)
{
// TODO: Get Unit by key
var unit = $"My Unit with Id: {unitKey}";
return Ok(unit);
}
}
Any help would be greatly appreciated.
Probably you should use nameof(UnitsController.Post) as the actionName value, and new { unitKey = unitKey } as the routeValues value on your CreatedAtAction response.
I want to log the each action method parameter name and its
corresponding values in the database as key value pair. As part of
this, I am using OnActionExecuting ActionFilterAttribute, since it
will be the right place (OnActionExecuting method will get invoke for
all controller action methods call) to get Action Executing context.
I am getting the value for .Net types (string, int, bool). But I am
unable to get the value of the User defined types (custom types).
(ex: Login model). My model might have some other nested user
defined types as well.
I was trying to get the values of the user defined types but I am
getting the only class name as string. I hope we can do in
reflection.
Could you please anyone assist to resolve the issue. since I am new
to reflection. It will helpful to me. Thanks in Advance.
I need to get the name and value of these types in OnActionExecuting.
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
ActionParameter = new SerializableDictionary<string,string>();
if(filterContext.ActionParameter != null)
{
foreach(var paramter in filterContext.ActionParameter)
{
//able to get returnUrl value
//unable to get model values
ActionParameter.Add(paramter.Key, paramter.Value);
}
}
}
public ActionResult Login(LoginModel model, string returnUrl)
{
return View(model);
}
User defined type
public class LoginModel
{
public string UserName {get;set;}
public string Password {get;set;}
//User defined type
public UserRequestBase Request {get;set;}
}
//User defined type
public class UserRequestBase
{
public string ApplicationName {get;set;}
}
I am able to get the value of the returnUrl (login method param) in OnActionExecuting but not for model (login method param). I am able to see the values, but don't know how to access it, I used typeof even though I am unable to get it, but I need generic because i have 20 methods in controller so I could not only for LoginModel.
This answer isn't exactly what you want - based on your question - but I think it will work better for what want to accomplish. Quick aside...
Playing around with reflection and nested classes in this instance, lead to some SO (a propos?) errors for me...
So, a better path, maybe? Rather than trying to get/cast the property names, values (types?) from 'context.ActionParameters,` I found it was much easier to let a Json serialization do the work for me. You can then persist the Json object, then deserialize... pretty easy.
Anyway, here's the code:
using Newtonsoft.Json; // <-- or some other serialization entity
//...
public class LogActions : ActionFilterAttribute, IActionFilter
{
// Using the example -- LoginModel, UserRequestBase objects and Login controller...
void IActionFilter.OnActionExecuting(ActionExecutingContext context)
{
var param = (Dictionary<String, Object>)context.ActionParameters;
foreach (var item in param.Values)
{
string itemName = item.GetType().Name.ToString();
string itemToJson = JsonConvert.SerializeObject(item);
// Save JsonObject along with whatever other values you need (route, etc)
}
}
}
Then when you retrieve the Json object from the database you just have to deserialize / cast it.
LoginModel model = (LoginModel)JsonConvert.DeserializeObject(itemToJson, typeof(LoginModel));
From example:
public class LoginModel
{
public string UserName {get;set;}
public string Password {get;set;}
//User defined type
public UserRequestBase Request {get;set;}
}
//User defined type
public class UserRequestBase
{
public string ApplicationName {get;set;}
}
Controller used in example:
public ActionResult Login(LoginModel model, string returnUrl)
{
return View(model);
}
Hope this helps. If there are further issues with this please let me know and I will try to help.
I'm testing the new ApiController in asp.net mvc 4 beta but when I try to return an class that looks like the following only a few properties gets serialized?
public class PageModel : IPageModel {
public string Id { get; set; }
public virtual IPageMetadata Metadata { get; private set; }
public PageModel() {
Metadata = new PageMetadata();
}
}
this is the code in my api controller
// GET /api/pages/5
public PageModel Get(string id) {
return new PageModel { Id = "pages/1", Metadata = {Name = "Foo"} };
}
and this is the result
{
Id: "pages/1",
Parent: null
}
Is it possible to get the complete object and not only a few things?
Readonly properties are not serialized. Make the setter of the Metadata property public if you want it to be serialized. I think that this behavior is normal for input parameters but not for output which is your case. IMHO it's a bug that could be workarounded by using a JSON serializer which supports this but maybe they will fix it before the final release and allow readonly properties to be serialized for output parameters.
Actually it's not a big pain, because you should be using view models anyway, so simply map your domain model to a view model and have your method return this view model which will contain only the properties that you need to actually expose to the client. This view model will contain properties with public getters and setters.