POSTing to an action with files and a parameter in ASP.NET MVC3

Question

This is a follow-up question to ASP.NET MVC 3 - File Upload. I have a URL syntax that I cannot change. I need to upload files to a URL in the syntax of "/person/{personID}/files". Currently, I am trying the following:

index.html

<form action="/person/2/files" method="post" enctype="multipart/form-data">
    <div>Please choose a file to upload.</div>
    <div><input id="fileUpload" type="file" /></div>

    <div><input type="submit" value="upload" /></div>
</form>

The personID parameter value is dynamically populated when the form loads. Regardless, when I click "upload", I'm posting back to the following action:

UploadController.cs

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult UploadFile(int uniqueID)
{
  foreach (string file in Request.Files)
  {
    // Request.Files is empty
  }

  return View();
}

How do I POST both a collection of files AND a parameter using the URL syntax of "/person/{personID}/files"? I know this is a very specific request. I have run out of time on my project and I'm totally confused why the approach I'm using doesn't work. Can somebody please help me?

Thank you so very much.

Answer 1

Assuming you have a route defined for this custom url:

routes.MapRoute(
    "Upload",
    "person/{uniqueid}/files",
    new { controller = "Upload", action = "UploadFile" }
);

you just need to give your file input a name:

<div><input id="fileUpload" type="file" name="file" /></div>

Also I would recommend you to use action arguments instead of looping through Request.Files:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult UploadFile(int uniqueID, HttpPostedFileBase file)
{
    return View();
}

and if you wanted to post multiple files:

<div><input type="file" name="files" /></div>
<div><input type="file" name="files" /></div>
<div><input type="file" name="files" /></div>
...

use a collection:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult UploadFile(int uniqueID, IEnumerable<HttpPostedFileBase> files)
{
    return View();
}

You might also find the following blog post useful.

Or even better, use a view model:

public class MyViewModel
{
    public int UniqueID { get; set; }
    public IEnumerable<HttpPostedFileBase> Files { get; set; }
}

and then:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult UploadFile(MyViewModel model)
{
    return View();
}