Web Api Odata action methods using Get verb return 404

Question

I'm trying to expose a document stream as an Action Method on a specific type. It would look something like this:

/odata/MyType(123)/stream <-- this returns a binary stream of data.

When accessing the above endpoint using GET I only get a 404, even though the endpoint is exposed as [HttpGet] on the Controller.

Sematically it would make sense to access this resource using the Get verb, as this is simply an operation for retrieval of data, and not side-effecting.

So far I've only gotten this to work by exposing the action method under the POST-verb.

The action method controller implementation currently look like this:

[HttpPost] // <-- I want this to be [HttpGet]
public HttpResponseMessage Test([FromODataUri] int key, ODataActionParameters parameters)
{
    var fileStream = File.OpenRead(@"c:\somefile");

    return new HttpResponseMessage(HttpStatusCode.OK)
        {
            Content = new StreamContent(fileStream)
        };
}

The code for registering the action method on 'MyType'

var entityTypeConfiguration = mapper.Builder.Entity<MyType>();
var actionConfiguration = entityTypeConfiguration.Action("stream");
actionConfiguration.Returns<HttpResponseMessage>();

The implementation is inspired by this article: http://www.asp.net/web-api/overview/odata-support-in-aspnet-web-api/odata-actions

Anyone know how I can possible expose this action method as a Get?

Answer 1

Question is old, but I have been struggling with this and the solution I found in my case may be useful for others: define the "Action" GET as a "Function" instead of an "Action".

In the scenario presented in the question, this would be:

var actionConfiguration = entityTypeConfiguration.Function("stream");

This is recommended in the documentation: "The difference between actions and functions is that actions can have side effects, and functions do not. Both actions and functions can return data."