I am coming from a heavy Java/Spring background and trying to transition some knowledge over to ASP.NET Core 6.
In Spring, on a RestController, I am able to route the request based on the presence of a query parameter.
So a HttpRequest with the uri: /students?firstName=Kevin can be routed to a different controller method than a HttpRequest with the uri: /students.
In ASP.NET Core 6, I am unable to determine if the equivalent is possible after working through some examples and reading the documentation for Web API.
Here is what I am trying to achieve, is this possible using two methods and routing configuration that will discern which controller method to invoke based on the query parameter?
[ApiController]
[Route("Students")]
public class StudentHomeProfileController : ControllerBase
{
[HttpGet] //Route here when no parameters provided
public async Task<ActionResult<IEnumerable<Student>>> GetStudentAsync()
{
/* Code omitted */
}
[HttpGet] //Route here when firstName query param provided
public async Task<ActionResult<IEnumerable<Student>>> SearchStudentAsync([FromQuery] string firstName)
{
/* Code omitted */
}
}
While filtering by query parameters does not come with ASP.NET Core out of the box, it's not too hard to supply this functionality on your own.
When it comes to extensibility, ASP.NET has some superpowers, one of them is IActionConstraint, which
Supports conditional logic to determine whether or not an associated action is valid to be selected for the given request. (Source)
Creating an annotation to filter for query parameters is as easy as
[AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
public class QueryParameterConstraintAttribute : Attribute, IActionConstraint
{
private readonly string _parameterName;
public QueryParameterConstraintAttribute(string parameterName)
{
this._parameterName = parameterName;
}
public bool Accept(ActionConstraintContext context)
{
return context.RouteContext.HttpContext.Request.Query.Keys.Contains(this._parameterName);
}
public int Order { get; }
}
All that's left is annotating your controller method with that constraint
[HttpGet] //Route here when firstName query param provided
[QueryParameterConstraint("firstName")]
public async Task<ActionResult<IEnumerable<Student>>> SearchStudentAsync([FromQuery] string firstName)
{
/* Code omitted */
}
In a quick test I was able to confirm that it seems to work as intended, even if you add multiple of those attributes for different query parameters (if all conditions match, the route is called).
(Please note, this was tested with .NET Core 2.1. Anyway, it shuold be pretty much the same with .NET 6)
I think you are looking for something like this, you need to specify the parameter in the "HttpGet" attribute
https://learn.microsoft.com/en-us/aspnet/core/mvc/controllers/routing?view=aspnetcore-6.0#attribute-routing-with-http-verb-attributes
[Route("api/[controller]")]
[ApiController]
public class Test2Controller : ControllerBase
{
[HttpGet] // GET /api/test2
public IActionResult ListProducts()
{
return ControllerContext.MyDisplayRouteInfo();
}
[HttpGet("{id}")] // GET /api/test2/xyz
public IActionResult GetProduct(string id)
{
return ControllerContext.MyDisplayRouteInfo(id);
}
[HttpGet("int/{id:int}")] // GET /api/test2/int/3
public IActionResult GetIntProduct(int id)
{
return ControllerContext.MyDisplayRouteInfo(id);
}
[HttpGet("int2/{id}")] // GET /api/test2/int2/3
public IActionResult GetInt2Product(int id)
{
return ControllerContext.MyDisplayRouteInfo(id);
}
}
You are trying to differentiate API calls using query params. this is not the way to do this. if you want to separate the calls you should probably use path params instead.
Read more about Routing in ASP.NET Core - https://learn.microsoft.com/en-us/aspnet/core/fundamentals/routing?view=aspnetcore-6.0
I need to write a Web API for this request:
{apiUrl}/api/sessions/byhour?startTime=2021-06-30T01:00:00&endTime=2021-06-30T03:00:00
So I have this controller and method:
[ApiController]
[Route("/api/sessions/byhour")]
public class LoginStatsByHourController : ControllerBase
{
[HttpGet, Route("{startTime=0001-01-01T12:00:00}/{endTime=9999-12-31T11:59:59}")]
public List<SessionEntry> GetSessionEntryByDate(string startTime, string endTime)
{...}
}
I tested this request:
https://localhost:5001/api/sessions/byhour/2021-07-01T14%3A00%3A00/2021-07-01T16%3A00%3A00
which essentially equals to:
https://localhost:5001/api/sessions/byhour/2021-07-01T14:00:00/2021-07-01T16:00:00
and everything works fine. But when I try this request:
https://localhost:5001/api/sessions/byhour?startTime=2021-07-01T14:00:00&endTime=2021-07-01T16:00:00
(notice ? and &). And I discovered that these arguments are ignored and the default ones (0001-01-01T12:00:00 and 9999-12-31T11:59:59) are used instead. Why is that so?
Try this :
[HttpGet]
public List<SessionEntry> GetSessionEntryByDate(string startTime, string endTime)
{...}
and call it like this : https://localhost:5001/api/sessions/byhour/GetSessionEntryByDate?startTime=2021-07-01T14:00:00&endTime=2021-07-01T16:00:00
for further reading : checkout this link
It ignores your arguments, because if you want to use a query string you have to remove "{startTime}/{endTime}" and sometimes ( depends on the version) have to add [FromQuery] attribute to each input parameter
[HttpGet]
public List<SessionEntry> GetSessionEntryByDate(string startTime="0001-01-01T12:00:00",
string endTime="9999-12-31T11:59:59")
{...}
}
If you still want to use MVC routing , try this
[HttpGet("{startTime?}/{endTime?}")]
public List<SessionEntry> GetSessionEntryByDate(string startTime="0001-01-01T12:00:00",
string endTime="9999-12-31T11:59:59")
{...}
}
I've created a simple .NET core controller and am trying to query it from Angular.
The problem is that whenever I send a post request to my login action, I always receive null parameters! The weird thing though is that upon investigating, the request body/payload clearly shows my parameters are set.
See my screenshot for an example of what I mean.
I have tried my best and have been reading through similar problems for the past few hours, but haven't had any success ðŸ˜
So my question is: What is causing my null parameters? .NET core must be doing something that I'm not aware of.
If you think seeing more code or the entire project would help, don't hesitate to ask!
You can't get two separate parameters from body, cause it is going to bind email and password as properties of the parameter, not exact parameters. You need to create an object, which defines properties with those names, and use that object in the parameter
class Login
{
public string Email { get; set; }
public string Password { get; set; }
}
In the action method parameter
([FromBody]Login model)
I suggest to create class with properties email and password.And using [FromBody] attribute.
public class LoginModel
{
public string Email {get;set;}
public string Password {get;set}
}
[HttpPost]
[Route("login")
public async Task<IActionResult> Login([FromBody] LoginModel model)
{
// your code
}
Aloha :D
I would like to create a dynamic route binding.
What I mean by this, is basically replacing the Query String with a dynamic route.
Example:
Instead of this:
POST http://localhost:5000/api/documents?templatename=individualemploymentagreement
this:
POST http://localhost:5000/api/documents/individualemploymentagreement
Note: after "http://localhost:5000/api/documents/" I want to put anything I want, but this route will always be used and what comes after should be used like a variable. Obviously, this will lead to a non-existing API Route at the moment. But is there any way to deal with this?
Note 2: The reasons I want to use this are:
- According to RESTful services "rules", query strings should be used just for queries, In this case I'm not using a query, I'm calling a generic document service, which however, treats every document slightly different when needed. So query strings are not recommended in my case.
- This service will deal with hundreds of document types, so I can't really make a different path / api for each one of them. So this is not recommended as well.
My code (In which I'm using a query string for {templateName}:
namespace DocumentGenerator.Api.Controllers
{
[Route("api/{controller}")]
[ApiController]
public class DocumentsController : ControllerBase
{
//useless details
[HttpPost]
public async Task<IActionResult> Generate([FromQuery] string templateName, [FromBody] object properties)
{
// according to {templateName} do this or that...
// useless details
}
}
}
What I would want in code:
namespace DocumentGenerator.Api.Controllers
{
[Route("api/{controller}")]
[ApiController]
public class DocumentsController : ControllerBase
{
//useless details
[HttpPost("{templateName}"]
public async Task<IActionResult> Generate([FromBody] object properties)
{
// according to {templateName} do this or that...
// useless details
}
}
}
You can specify the parameter name as a route attribute value in HttpPost :
[HttpPost("{templateName}"]
public async Task<IActionResult> Generate(string templateName, [FromBody] object properties)
{
}
or even
[HttpPost("/api/documents/{templateName}"]
public async Task<IActionResult> Generate(string templateName, [FromBody] object properties)
{
}
I'm using System.Web.Http.RouteAttribute and System.Web.Http.RoutePrefixAttribute to enable cleaner URLs for my Web API 2 application. For most of my requests, I can use routing (eg. Controller/param1/param2) or I can use query strings (eg. Controller?param1=bob¶m2=mary).
Unfortunately, with one of my Controllers (and only one), this fails. Here is my Controller:
[RoutePrefix("1/Names")]
public class NamesController : ApiController
{
[HttpGet]
[Route("{name}/{sport}/{drink}")]
public List<int> Get(string name, string sport, string drink)
{
// Code removed...
}
[HttpGet]
[Route("{name}/{drink}")]
public List<int> Get(string name, string drink)
{
// Code removed...
}
}
When I make a request to either using routing, both work fine. However, if I use a query string, it fails, telling me that that path does not exist.
I have tried adding the following to my WebApiConfig.cs class' Register(HttpConfiguration config) function (before and after the Default route), but it did nothing:
config.Routes.MapHttpRoute(
name: "NameRoute",
routeTemplate: "{verId}/Names/{name}/{sport}/{drink}",
defaults: new { name = RouteParameter.Optional, sport = RouteParameter.Optional, drink = RouteParameter.Optional },
constraints: new { verId = #"\d+" });
So for clarity, I would like to be able to do both this:
localhost:12345/1/Names/Ted/rugby/coke
localhost:12345/1/Names/Ted/coke
and,
localhost:12345/1/Names?name=Ted&sport=rugby&drink=coke
localhost:12345/1/Names?name=Ted&drink=coke
but sadly the query string versions don't work! :(
Updated
I've removed the second Action altogether and now trying to use just a singular Action with optional parameters. I've changed my route attribute to [Route("{name}/{drink}/{sport?}")] as Tony suggested to make sport nullable, but this now prevents localhost:12345/1/Names/Ted/coke from being a valid route for some reason. Query strings are behaving the same way as before.
Update 2
I now have a singular action in my controller:
[RoutePrefix("1/Names")]
public class NamesController : ApiController
{
[HttpGet]
[Route("{name}/{drink}/{sport?}")]
public List<int> Get(string name, string drink, string sport = "")
{
// Code removed...
}
}
but still, using query strings does not find a suitable path, while using the routing method does.
I was facing the same issue of 'How to include search parameters as a query string?', while I was trying to build a web api for my current project. After googling, the following is working fine for me:
Api controller action:
[HttpGet, Route("search/{categoryid=categoryid}/{ordercode=ordercode}")]
public Task<IHttpActionResult> GetProducts(string categoryId, string orderCode)
{
}
The url I tried through postman:
http://localhost/PD/search?categoryid=all-products&ordercode=star-1932
http://localhost/PD is my hosted api
After much painstaking fiddling and Googling, I've come up with a 'fix'. I don't know if this is ideal/best practice/plain old wrong, but it solves my issue.
All I did was add [Route("")] in addition to the route attributes I was already using. This basically allows Web API 2 routing to allow query strings, as this is now a valid Route.
An example would now be:
[HttpGet]
[Route("")]
[Route("{name}/{drink}/{sport?}")]
public List<int> Get(string name, string drink, string sport = "")
{
// Code removed...
}
This makes both localhost:12345/1/Names/Ted/coke and localhost:12345/1/Names?name=Ted&drink=coke valid.
With the Attribute routing you need to specify default values so they would be optional.
[Route("{name}/{sport=Football}/{drink=Coke}")]
Assigning a value will allow it to be optional so you do not have to include it and it will pass the value to specify.
I have not tested the query string for this but it should work the same.
I just re-read the question and I see that you have 2 Get verbs with the same path, I believe this would cause conflict as routing would not know which one to utilize, perhaps using the optional params will help. You can also specify one can be null and do checking in the method as to how to proceed.
[Route("{name}/{sport?}/{drink?}")]
Then check the variables in the method to see if they are null and handle as needed.
Hope this helps, some? lol
If not perhaps this site will, it has more details about attribute routing.
http://www.asp.net/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2
Clip from that site:
Optional parameters and default values You can specify that a
parameter is optional by adding a question mark to the parameter, that
is:
[Route("countries/{name?}")]
public Country GetCountry(string name = "USA") { }
Currently, a default value must be specified on the optional parameter
for action selection to succeed, but we can investigate lifting that
restriction. (Please let us know if this is important.)
Default values can be specified in a similar way:
[Route("countries/{name=USA}")]
public Country GetCountry(string name) { }
The optional parameter '?' and the default values must appear after
inline constraints in the parameter definition.
Just a side note from my part as well. In order for queryString params to work, you need to provide a default value for your method parameters to make it optional. Just as you would also do when normally invoking a C# method.
[RoutePrefix("api/v1/profile")]
public class ProfileController : ApiController
{
...
[HttpGet]
[Route("{profileUid}")]
public IHttpActionResult GetProfile(string profileUid, long? someOtherId)
{
// ...
}
...
}
This allows me to call the endpoint like this:
/api/v1/profile/someUid
/api/v1/profile/someUid?someOtherId=123
Using Route("search/{categoryid=categoryid}/{ordercode=ordercode}") will enable you to use both Querystrings and inline route parameters as answered by mosharaf hossain. Writing this answer as this should be top answer and best way. Using Route("") will cause problems if you have multiple Gets/Puts/Posts/Deletes.
Here's a slight deviant of #bhargav kishore mummadireddy's answer, but an important deviation. His answer will default the querystring values to an actual non-empty value. This answer will default them to empty.
It allows you to call the controller through path routing, or using the querystring. Essentially, it sets the default value of the querystring to empty, meaning it will always be routed.
This was important to me, because I want to return 400 (Bad Request) if a querystring is not specified, rather than having ASP.NET return the "could not locate this method on this controller" error.
[RoutePrefix("api/AppUsageReporting")]
public class AppUsageReportingController : ApiController
{
[HttpGet]
// Specify default routing parameters if the parameters aren't specified
[Route("UsageAggregationDaily/{userId=}/{startDate=}/{endDate=}")]
public async Task<HttpResponseMessage> UsageAggregationDaily(string userId, DateTime? startDate, DateTime? endDate)
{
if (String.IsNullOrEmpty(userId))
{
return Request.CreateResponse(HttpStatusCode.BadRequest, $"{nameof(userId)} was not specified.");
}
if (!startDate.HasValue)
{
return Request.CreateResponse(HttpStatusCode.BadRequest, $"{nameof(startDate)} was not specified.");
}
if (!endDate.HasValue)
{
return Request.CreateResponse(HttpStatusCode.BadRequest, $"{nameof(endDate)} was not specified.");
}
}
}
I use FromUri attribute as solution
[Route("UsageAggregationDaily")]
public async Task<HttpResponseMessage> UsageAggregationDaily([FromUri] string userId = null, [FromUri] DateTime? startDate = null, [FromUri] DateTime? endDate = null)
Since you have [Route("{name}/{drink}/{sport?}")] as attribute routing, this code will never be hit.
config.Routes.MapHttpRoute(
name: "NameRoute",
routeTemplate: "{verId}/Names/{name}/{sport}/{drink}",
defaults: new { name = RouteParameter.Optional, sport = RouteParameter.Optional, drink = RouteParameter.Optional },
constraints: new { verId = #"\d+" });
So only the attribute route [Route("{name}/{drink}/{sport?}")] is going to be honored here. Since your request localhost:12345/1/Names?name=Ted&sport=rugby&drink=coke, doesn't have name, sport or drink in the URL it is not going to match this attribute route. We do not consider the query string parameters when matching the routes.
To solve this, you need to make all 3 optional in your attribute route. Then it will match the request.