I am trying to map /{Controller}/{Variable1}/{Variable2}/{Variable3} to a GET method in controller
public TestController{
public ActionResult Get([FromUrl] Entity instance){}
}
So I need to map variables to the entity.
To put it into an example
/Product/{category}/{filter1}/{filter2}/
Entity
public class ProductSearchRequest
{
public string Category{get;set;}
public string filter1 {get;set;}
public string filter2 {get;set;}
}
Controller
public ProductController: Controller {
public ActionResult GET([FromUri] ProductSearchRequest productSearchRequest){
}
}
[EDITED]
Had to do following changes to get this working
Instead of RouteCollection.MapHttpRoute use HttpConfiguration.Routes.MapHttpRoute as this is API routing not MVC routing.
Inherit controller from ApiController rather than Controller which I was before.
Basically you are not going to be able to do that. Complex types are not compatible with the routing mechanism.
Take a read of this article. But this paragraph explains why the routing mechanism cannot do what you are asking.
A complex type can only bind to the URI through a custom binding. But
in that case, the framework cannot know in advance whether the
parameter would bind to a particular URI. To find out, it would need
to invoke the binding. The goal of the selection algorithm is to
select an action from the static description, before invoking any
bindings. Therefore, complex types are excluded from the matching
algorithm.
Therefore the basic rule is:
For every parameter of the action, if the parameter is taken from the
URI, then the parameter name must be found either in the route
dictionary or in the URI query string. (Optional parameters and
parameters with complex types are excluded.)
Which means you need to define your action like so:
public ActionResult GET(string Category, string filter1, string filter2){
}
And your route template:
/{controller}/{category}/{filter1}/{filter2}/
Related
Please find my HomeController and DemoController
class HomeController{
#RequestMapping(value="index")
public void home(){
}
}
class DemoController{
#RequestMapping(value="index")
public void demo(){
}
}
when I try to send a request to index, which one will get executed?
I wanted to know how can we have same request mapping value for multiple controllers
https://stackoverflow.com/a/34590355/2682499 is only partially correct at this point.
You can have multiple controller methods use the same URI so long as you provide Spring enough additional information on which one it should use. Whether or not you should do this is a different question. I would certainly not recommend using the same URI in two separate controller classes to avoid confusion, though.
You can do something like this:
class HomeController{
#RequestMapping(value="/index", params = {"!name", "!foo"})
public List<Something> listItems(){
// retrieve Something list
}
#RequestMapping(value="/index", params = "name")
public List<Something> listItems(String name) {
// retrieve Something list WHERE name LIKE %name%
}
#RequestMapping(value="/index", params = {"!name", "foo"})
public List<Something> listItems(String foo) {
// Do something completely different
}
}
For the full documentation on what is possible when overloading URIs you should reference the #ReqeustMapping documentation: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/RequestMapping.html. And, specifically https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/RequestMapping.html#params-- for the section request parameters.
In Spring Web MVC this is not possible. Each mapping must be unique in your context. If not, you will receive a RuntimeException during context initialization.
You cannot even use parameters to differentiate your endpoints because they are not evaluated while searching for a suitable handler (applicable for Servlet environments). From #RequestMapping javadoc:
In a Servlet environment, parameter mappings are considered as restrictions that are enforced at the type level. The primary path mapping (i.e. the specified URI value) still has to uniquely identify the target handler, with parameter mappings simply expressing preconditions for invoking the handler.
Note that you can do the opposite, so multiple URLs can point to the same handler. Have a look at Spring MVC: Mapping Multiple URLs to Same Controller
Unfortunately, this is not possible. The request mapping has to be unique otherwise the application can't determine which method the incoming request should be mapped to.
What you can do instead is to extend the request mapping:
class HomeController{
#RequestMapping(value="home/index")
public void home(){
}
}
class DemoController{
#RequestMapping(value="demo/index")
public void demo(){
}
}
What are the benefits/advantages we get if we specify this frombody and fromuri attribute in web-api?
Web API parameter binding expects simple type values coming from query string, and complex types like array coming from the body of the request. Hence if you have an action method like this one:
public class EmployeesController : ApiController
{
public IHttpActionResult Get(int id, string[] names)
{
return Ok("Method Called");
}
}
,and if you want to formulate your request like this:
/api/employees?id=1&names=Fred&names=Anna
, then without [FromUri] the value of "names" parameter won't be bound.
So your API method must be like this in order to get all parameters bound:
public IHttpActionResult Get(int id,[FromUri] string[] names)
{
return Ok("Method Called");
}
More from here: http://www.asp.net/web-api/overview/formats-and-model-binding/parameter-binding-in-aspnet-web-api
I'm using MongoDB with an ASP.NET Web Api (2) application, and want to accept ObjectId arguments in the Web Api methods.
I've written a custom model binder for the ObjectId type, and it when adding it to the Get method of a controller, everything works.
[Route("{id}")]
public HttpResponseMessage Get(String type, [ModelBinder(typeof(ObjectIdModelBinder))]ObjectId id) {
But I need to do this in several methods and controllers, so I would rather put it somewhere central. I've read that I can register the binder centrally like this:
public static void Register(HttpConfiguration config) {
var provider = new SimpleModelBinderProvider(typeof(ObjectId), new ObjectIdModelBinder());
config.Services.Insert(typeof(ModelBinderProvider), 0, provider);
}
But that's not working!
Any ideas? Not really sure what the config.Services collection should contain, but I'm having a hard time locating the binder I insert.
With WebAPI even if you register a model binder, you still need to attach the [ModelBinder] to the input parameter, you just don't have to specify the type anymore so your method now looks like this:
[Route("{id}")]
public HttpResponseMessage Get(String type, [ModelBinder]ObjectId id) {
If you want to skip adding the attribute every time you declare a parameter of this type, then you have to look at writing a custom IActionValueBinder (which can be made very simple if you just extend the DefaultActionValueBinder) which is the default implementation. You might want to look at this post for pointers:
http://www.strathweb.com/2013/04/asp-net-web-api-parameter-binding-part-1-understanding-binding-from-uri/
Does WebAPI can handle ValidationAttribute on action parameter?
For instance:
public class SampleController : ApiController
{
public string Get([RegularExpression("sampleExpression")]string id)
{
return "result";
}
}
In this sample WebAPI doesn't invoke any methods of RegularExpressionAttribute (or any other data annotation attribute) to validate input parameter. But in case if we passing an object as parameter, for instance a class then WebAPI can validate properties.
Is it a bug? Or I'm doing something wrong?
UPD: It's an open issue:
http://aspnetwebstack.codeplex.com/workitem/24?PendingVoteId=24
Does anyone can suggest a workaround?
This is a genuine question, I'm curious why not just do something like :
public class SampleController : ApiController
{
public string Get(string id)
{
RegularExpressionHelper.ValidateWith("sampleExpression",id);
return "result";
}
}
To me this seems to be equivalently concise. It is obvious when the validation occurs. I can safely assume that if the validation fails then an exception will be thrown. I can easily add additional validation and be confident of the order in which they occur.
Regarding the attribute method, I don't know if the validation is used as part of the route matching, I have no idea what happens if it fails. I don't know what filters run before or after the validation. I'm sure if I knew MVC better I would know the answer to these questions, but I don't see the advantage of using an attribute that makes my code's behaviour dependent on some framework controlled infrastructure.
Am I missing some significant benefit?
I had the same doubt. My workaround consists in creating a class just for encapsulating the parameter, so I can decorate it with the validation attribute I want. I could use the workaround proposed by Darrel in his answer, but I have a filter that checks if ModelState.IsValid before entering the action, so I need to validate before the action gets executed.
[ModelBinder]
public class Item
{
[RegularExpression("sampleExpression")]
public string Id { get; set; }
}
The class must be annotated with [ModelBinder], otherwise the parameter binding mechanism will try to extract the id field from the body of the request. Read this article for more info.
Also, note that Id is now in PascalCase instead of camelCase. Read this article to understand how the conversion is made.
The action signature is:
public string Get(Item item)
In ASP.Net Web API (RC) I have a test model class like so:
[ModelBinder]
public class TestRequest
{
public string Foo { get; set; }
public string Bar { get; set; }
}
My controller looks like this:
public class TestController : ApiController
{
public TestRequest Get(TestRequest model)
{
return model;
}
}
Now if I invoke the action via:
http://.../test?foo=abc&bar=xyz
neither values bind, because the model binder is expecting model prefixes, such that I actually need to call:
http://.../test?model.foo=abc&model.bar=xyz
I can understand that this is so that other action parameters can bind correctly, but in my case the model is a clean way of encapsulating all the possible action parameters so that I don't need to have a nasty action method signature with a whole lot of optional parameters. It also allows for easy model validation.
Is there any easy way to cause model binding to behave the same way as it would in MVC, or in a POST request?
Removing the ModelBinder attribute from your model class should work in the example you've posted. You'll run into issues for more complex method signatures, see Rick Strahl's comment: http://blogs.msdn.com/b/jmstall/archive/2012/04/16/how-webapi-does-parameter-binding.aspx#10302750