Calling Web API from MVC controller

Question

I have a WebAPI Controller within my MVC5 project solution. The WebAPI has a method which returns all files in a specific folder as a Json list:

[{"name":"file1.zip", "path":"c:\\"}, {...}]

From my HomeController I want to call this Method, convert the Json response to List<QDocument> and return this list to a Razor view. This list might be empty: [] if there are no files in the folder.

This is the APIController:

public class DocumentsController : ApiController
{
    #region Methods
    /// <summary>
    /// Get all files in the repository as Json.
    /// </summary>
    /// <returns>Json representation of QDocumentRecord.</returns>
    public HttpResponseMessage GetAllRecords()
    {
      // All code to find the files are here and is working perfectly...

         return new HttpResponseMessage()
         {
             Content = new StringContent(JsonConvert.SerializeObject(listOfFiles), Encoding.UTF8, "application/json")
         };
    }               
}

Here is my HomeController:

public class HomeController : Controller
{
     public Index()
     {
      // I want to call APi GetAllFiles and put the result to variable:
      var files = JsonConvert.DeserializeObject<List<QDocumentRecord>>(API return Json);
      }
 }

Finally this is the model in case you need it:

public class QDocumentRecord
{
      public string id {get; set;}
      public string path {get; set;}
   .....
}

So how can I make this call?

Why don't you call it as any other method? Add reference, initiate and call the method... — Kaf, Apr 17 '15 at 13:02
Just a heads-up on using JsonConvert in your ApiController... Doing this automatically is one of the flagship features WebAPI, — spender, Apr 17 '15 at 13:04

score 24 · Accepted Answer · edited May 23 '17 at 10:31

From my HomeController I want to call this Method and convert Json response to List

No you don't. You really don't want to add the overhead of an HTTP call and (de)serialization when the code is within reach. It's even in the same assembly!

Your ApiController goes against (my preferred) convention anyway. Let it return a concrete type:

public IEnumerable<QDocumentRecord> GetAllRecords()
{
    listOfFiles = ...
    return listOfFiles;
}

If you don't want that and you're absolutely sure you need to return HttpResponseMessage, then still there's absolutely no need to bother with calling JsonConvert.SerializeObject() yourself:

return Request.CreateResponse<List<QDocumentRecord>>(HttpStatusCode.OK, listOfFiles);

Then again, you don't want business logic in a controller, so you extract that into a class that does the work for you:

public class FileListGetter
{
    public IEnumerable<QDocumentRecord> GetAllRecords()
    {
        listOfFiles = ...
        return listOfFiles;
    }
}

Either way, then you can call this class or the ApiController directly from your MVC controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var listOfFiles = new DocumentsController().GetAllRecords();
        // OR
        var listOfFiles = new FileListGetter().GetAllRecords();

        return View(listOfFiles);
    }
}

But if you really, really must do an HTTP request, you can use HttpWebRequest, WebClient, HttpClient or RestSharp, for all of which plenty of tutorials exist.

In your example where would you put `FileListGetter`? Would be acceptable to put that logic in a model? — Alonso Urbano, Jul 25 '18 at 02:39

score 23 · Answer 2 · answered Jun 24 '16 at 10:59

Its very late here but thought to share below code. If we have our WebApi as a different project altogether in the same solution then we can call the same from MVC controller like below

public class ProductsController : Controller
    {
        // GET: Products
        public async Task<ActionResult> Index()
        {
            string apiUrl = "http://localhost:58764/api/values";

            using (HttpClient client=new HttpClient())
            {
                client.BaseAddress = new Uri(apiUrl);
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

                HttpResponseMessage response = await client.GetAsync(apiUrl);
                if (response.IsSuccessStatusCode)
                {
                    var data = await response.Content.ReadAsStringAsync();
                    var table = Newtonsoft.Json.JsonConvert.DeserializeObject<System.Data.DataTable>(data);

                }


            }
            return View();

        }
    }

kmcnamee · Answer 3 · 2015-04-17T13:11:32.283

8

Why don't you simply move the code you have in the ApiController calls - DocumentsController to a class that you can call from both your HomeController and DocumentController. Pull this out into a class you call from both controllers. This stuff in your question:

// All code to find the files are here and is working perfectly...

It doesn't make sense to call a API Controller from another controller on the same website.

This will also simplify the code when you come back to it in the future you will have one common class for finding the files and doing that logic there...

edited Apr 17 '15 at 13:11

answered Apr 17 '15 at 13:07

kmcnamee

5,097
2
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2

"It doesnt make sense to call a API Controller from another controller on the same website" +1 – spender Apr 17 '15 at 13:07
I have to design the API that way. the API is been used by other mobile apps. and I wan to send the results as a List to Razor view to do the filtering and... – A-Sharabiani Apr 17 '15 at 15:12
moving your internal logic where you generate your list of files to a common class should not impact the actual controller interface used by mobile apps. To them what happens in the controller is a black box. Simply pull the common logic to find the files to a common class used by both.. – kmcnamee Apr 17 '15 at 15:20
1

I used to think like this as well. Until recently, I found myself in a situation when actually calling from a controller to a web api controller is required: security standard in card payment industry doesn't allow the web to access database directly, but must through a web service (deployed on a private LAN). The idea is that even if the public web get hi-jacked, the attacker still not have direct access to your database yet. He can only call the internal web service himself, and it would be less dangerous. – Hoàng Long Oct 23 '15 at 02:21
1

tldr: the question is a valid use case. Your answer is still a valid consideration if security isn't the main concern – Hoàng Long Oct 23 '15 at 02:23

score 1 · Answer 4 · answered Apr 17 '15 at 13:03

1

well, you can do it a lot of ways... one of them is to create a HttpRequest. I would advise you against calling your own webapi from your own MVC (the idea is redundant...) but, here's a end to end tutorial.

answered Apr 17 '15 at 13:03

Leonardo

10,737
10
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155

score 1 · Answer 5 · answered Dec 09 '18 at 06:41

Controller:

    public JsonResult GetProductsData()
    {
        using (var client = new HttpClient())
        {
            client.BaseAddress = new Uri("http://localhost:5136/api/");
            //HTTP GET
            var responseTask = client.GetAsync("product");
            responseTask.Wait();

            var result = responseTask.Result;
            if (result.IsSuccessStatusCode)
            {
                var readTask = result.Content.ReadAsAsync<IList<product>>();
                readTask.Wait();

                var alldata = readTask.Result;

                var rsproduct = from x in alldata
                             select new[]
                             {
                             Convert.ToString(x.pid),
                             Convert.ToString(x.pname),
                             Convert.ToString(x.pprice),
                      };

                return Json(new
                {
                    aaData = rsproduct
                },
    JsonRequestBehavior.AllowGet);


            }
            else //web api sent error response 
            {
                //log response status here..

               var pro = Enumerable.Empty<product>();


                return Json(new
                {
                    aaData = pro
                },
    JsonRequestBehavior.AllowGet);


            }
        }
    }

    public JsonResult InupProduct(string id,string pname, string pprice)
    {
        try
        {

            product obj = new product
            {
                pid = Convert.ToInt32(id),
                pname = pname,
                pprice = Convert.ToDecimal(pprice)
            };



            using (var client = new HttpClient())
            {
                client.BaseAddress = new Uri("http://localhost:5136/api/product");


                if(id=="0")
                {
                    //insert........
                    //HTTP POST
                    var postTask = client.PostAsJsonAsync<product>("product", obj);
                    postTask.Wait();

                    var result = postTask.Result;

                    if (result.IsSuccessStatusCode)
                    {
                        return Json(1, JsonRequestBehavior.AllowGet);
                    }
                    else
                    {
                        return Json(0, JsonRequestBehavior.AllowGet);
                    }
                }
                else
                {
                    //update........
                    //HTTP POST
                    var postTask = client.PutAsJsonAsync<product>("product", obj);
                    postTask.Wait();
                    var result = postTask.Result;
                    if (result.IsSuccessStatusCode)
                    {
                        return Json(1, JsonRequestBehavior.AllowGet);
                    }
                    else
                    {
                        return Json(0, JsonRequestBehavior.AllowGet);
                    }

                }




            }


            /*context.InUPProduct(Convert.ToInt32(id),pname,Convert.ToDecimal(pprice));

            return Json(1, JsonRequestBehavior.AllowGet);*/
        }
        catch (Exception ex)
        {
            return Json(0, JsonRequestBehavior.AllowGet);
        }

    }

    public JsonResult deleteRecord(int ID)
    {
        try
        {
            using (var client = new HttpClient())
            {
                client.BaseAddress = new Uri("http://localhost:5136/api/product");

                //HTTP DELETE
                var deleteTask = client.DeleteAsync("product/" + ID);
                deleteTask.Wait();

                var result = deleteTask.Result;
                if (result.IsSuccessStatusCode)
                {

                    return Json(1, JsonRequestBehavior.AllowGet);
                }
                else
                {
                    return Json(0, JsonRequestBehavior.AllowGet);
                }
            }



           /* var data = context.products.Where(x => x.pid == ID).FirstOrDefault();
            context.products.Remove(data);
            context.SaveChanges();
            return Json(1, JsonRequestBehavior.AllowGet);*/
        }
        catch (Exception ex)
        {
            return Json(0, JsonRequestBehavior.AllowGet);
        }
    }

Calling Web API from MVC controller

5 Answers5

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