routing-pitfalls.md

Routing Pitfalls

This is a collection of common pitfalls an OData developer should be aware of when building an API using this project.

Mixing ASP.NET Routing and OData Routing in one controller

Scenario Edm Model

public static IEdmModel GetEdmModel()
{
    var builder = new ODataConventionModelBuilder();
    builder.EntitySet<Customer>("Customers");
    return builder.GetEdmModel();
}

Incorrect Code ❌

[ApiController]
[Route("api/[controller]")]
public class CustomersController : Controller
{
    [HttpGet]
    EnableQuery(AllowedQueryOptions = AllowedQueryOptions.Expand)]
    public async Task<ActionResult<IEnumerable<Customer>>> GetCustomers()
    {}
}

Since "Customers" is a valid entity set in the Edm model, you will wind up with two routable endpoints exposed:

1. ~/api/Customers -- A non-odata endpoint
2. ~/odata/Customers -- An odata endpoint

Correct Code ✅

public class CustomersController : ODataController
{
    [HttpGet]
    EnableQuery(AllowedQueryOptions = AllowedQueryOptions.Expand)]
    public async Task<ActionResult<IEnumerable<Customer>>> GetCustomers()
    {}
}