ASP.NET Core MVC Mixed Route/FromBody Model Binding & Validation

Question

I am using ASP.NET Core 1.1 MVC to build an JSON API. Given the following model and action method:

public class TestModel {     public int Id { get; set; }      [Range(100, 999)]     public int RootId { get; set; }      [Required, MaxLength(200)]     public string Name { get; set; }      public string Description { get; set; } }  [HttpPost("/test/{rootId}/echo/{id}")] public IActionResult TestEcho([FromBody] TestModel data) {     return Json(new     {         data.Id,         data.RootId,         data.Name,         data.Description,         Errors = ModelState.IsValid ? null : ModelState.SelectMany(x => x.Value.Errors)     }); } 

The [FromBody] on my action method parameter is causing the model to be bound from the JSON payload that is posted to the endpoint, however it also prevents the Id and RootId properties from being bound via the route parameters.

I could break this up into to separate models, one bound from the route and one from the body or I could also force any clients to send the id & rootId as part of the payload, but both of those solutions seem to complicate things more than I'd like and don't allow me to keep the validation logic in a single place. Is there any way to get this situation working where the model can be bound properly and I can keep my model & validation logic together?

Answer 1

1. Install-Package HybridModelBinding

2. Add to Statrup:

   services.AddMvc()     .AddHybridModelBinder(); 

3. Model:

   public class Person {     public int Id { get; set; }     public string Name { get; set; }     public string FavoriteColor { get; set; } } 

4. Controller:

   [HttpPost] [Route("people/{id}")] public IActionResult Post([FromHybrid]Person model) { } 

5. Request:

   curl -X POST -H "Accept: application/json" -H "Content-Type:application/json" -d '{     "id": 999,     "name": "Bill Boga",     "favoriteColor": "Blue" }' "https://localhost/people/123?name=William%20Boga" 

6. Result:

   {     "Id": 123,     "Name": "William Boga",     "FavoriteColor": "Blue" } 

7. There are other advanced features.