ApiEndpoints: Binding parameters from multiple locations not working in .NET 6?

NuGet Package Version: 3.1.0
.NET SDK Version: 6.0-RC-1

I am trying to bind parameters from multiple locations as specified in the documentation, but it does not seem to work.

Endpoint:

[HttpPut("api/projects/{projectId}")]
public override async Task<ActionResult<UpdateProjectResponse>> HandleAsync([FromRoute] UpdateProjectRequest request, CancellationToken cancellationToken = default)
{

}

Request:

public class UpdateProjectRequest
{
    [FromRoute(Name = "projectId")] public Guid ProjectId { get; set; } = default!;

    [FromBody] public string Code { get; set; } = default!;

    [FromBody] public string Description { get; set; } = default!;

    [FromBody] public string Number { get; set; } = default!;
}

This is the response I get:

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
  "title": "One or more validation errors occurred.",
  "status": 400,
  "traceId": "00-8204c6f7087a1e60fb4c1ab5ac75c778-de42a5cad4fe62d6-00",
  "errors": {
    "$": [
      "The JSON value could not be converted to System.String. Path: $ | LineNumber: 0 | BytePositionInLine: 1.",
      "The input does not contain any JSON tokens. Expected the input to start with a valid JSON token, when isFinalBlock is true. Path: $ | LineNumber: 0 | BytePositionInLine: 0."
    ],
    "Code": [
      "The Code field is required.",
      "'Code' must not be empty."
    ],
    "Number": [
      "The Number field is required.",
      "'Number' must not be empty."
    ],
    "Description": [
      "The Description field is required.",
      "'Description' must not be empty."
    ]
  }
}

I am also using FluentValidation, but that should not matter because FluentValidation validates after model binding.

Could this be because something has changed in .NET 6 or am I just missing something?

About this issue

Original URL
State: closed
Created 3 years ago
Reactions: 1
Comments: 18 (7 by maintainers)

Most upvoted comments

What I have done myself as a workaround is creating a BaseAsyncEndpoint myself with multiple WithResponse classes. One with only one parameter, one with two parameters etc.

I have done it like this: https://gist.github.com/luuk777w/5f8d1a7a6f178da4884e87ca7c0b9e38 It works really well, and as a bonus it plays nice with Swagger. However, the downside of this approach is that you will limit the number of parameters by how many classes you define.

luuk777w on Jan 17, 2022

@ardalis I have just tested it and the issue remains. I have created a reproduction repo: https://github.com/luuk777w/ApiEndpointsIssueRepro

luuk777w on Jan 17, 2022

I am not having exactly the same result as described above, I do however not get the Id from the route (though it is displayed in swagger ui as a required route parameter), but the body also includes the id and this is what is being bound to the command object.

Not sure whether this is a swagger issue or an ApiEndpoint issue.

After finding a previous problem I managed to work around this issue, maybe it’ll help solve the underlying issue.

must include FromRoute in handler:

HandleAsync([FromRoute]FinishRequest request,

then the request can be split into two parts:

    public class FinishRequest
    {
        public const string Route = "/shift/{callsign}/end";

        [FromRoute(Name = "callsign")]
        public string CallSign { get; set; } = null!;

        [FromBody]
        public FinishRequestBody Body { get; set; } = null!;

        public class FinishRequestBody
        {
            /// <summary>
            /// The date and time when the shift was finished
            /// </summary>
            public DateTimeOffset EndTime { get; set; }
        }
    }

The only downside is that referencing the request will need an additional property: request.Body.EndTime . I don’t see this as a big deal as it further defines where the data is coming from.

As a bonus, Swagger displays and passes the request as expected too, and correctly defined the Body component.

Allann on Nov 23, 2021