Creating an MVC Controller Proxy for a Web API Controller

Question

I have an MVC project that is exposed externally. I have an internal Web API project.

For reasons beyond my control, I cannot expose the Web API project directly and I cannot add Web API Controllers to my MVC project.

I need to create an MVC Controller that will act as a proxy for a Web API Controller. I need the response from the MVC Controller to look as if the Web API was called directly.

What is the best way to accomplish this?

Is there a better approach than what I have so far?

How can I fix the error that I am getting?

Here is what I have so far:

MyMVCController

[HttpGet]
public HttpResponseMessage GetData(HttpRequestMessage request)
    {
        ...

        var response = proxy.GetData();

        return request.CreateResponse();
    }

MyProxyClass

public HttpResponseMessage GetData()
    {
        ...
        return HttpRequest(new HttpRequestMessage(HttpMethod.Get, uri));
    }

private HttpResponseMessage HttpRequest(HttpRequestMessage message)
    {
        HttpResponseMessage response;

        ...

        using (var client = new HttpClient())
        {
            client.Timeout = TimeSpan.FromSeconds(120);
            response = client.SendAsync(message).Result;
        }

        return response;
    }

In the MVC Controller, I am getting an InvalidOperationException on the request.CreateResponse() line. The error says:

The request does not have an associated configuration object or the provided configuration was null.

Any help would be greatly appreciated. I have searched Google and StackOverflow but I haven't been able to find a good solution for creating this proxy between MVC and Web API.

Thanks!

score 6 · Accepted Answer · edited Jul 24 '17 at 00:14

6

You can do it by just creating some JsonResult action in your controller which will return result of calling web API.

public class HomeController : Controller
{
    public async Task<JsonResult> CallToWebApi()
    {
        return this.Content(
            await new WebApiCaller().GetObjectsAsync(),
            "application/json"
        );
    }
}

public class WebApiCaller
{
    readonly string uri = "your url";

    public async Task<string> GetObjectsAsync()
    {
        using (HttpClient httpClient = new HttpClient())
        {
            return await httpClient.GetStringAsync(uri);
        }
    }
}

edited Jul 24 '17 at 00:14

Quality Catalyst

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answered Dec 29 '14 at 14:02

aleha_84

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1

Wouldn't that always return a 200 status code? I need to preserve whatever status code of the response from the Web API. Also, I don't want the Web API to serialize the object, the proxy de-serialize it, and then the MVC serialize the object again. – jkruer01 Dec 29 '14 at 14:10
you could always return status code you want base on result you achieve from web api call – aleha_84 Dec 29 '14 at 14:12
what about the serialize, de-serialize, serialize again issue? – jkruer01 Dec 29 '14 at 14:22
Also, what would happen if the Web Api returned an error message/response. The WebApiCaller would try to deserialize it into the expected object type which would then throw an error right? – jkruer01 Dec 29 '14 at 14:30
modified. Withou deserialization. For details look here: http://stackoverflow.com/a/9777889/1235390 – aleha_84 Dec 29 '14 at 14:31

Creating an MVC Controller Proxy for a Web API Controller

1 Answers1