Uploading CustomData with ng-file-upload and WebApi - angularjs

Question

I am trying to upload a file along with some metadata to a WebApi Service that I have created with ng-file-upload and Angular. I am getting the file name and bytes as expected, but I am not able to get the metadata I am passing as well. Here is what I am doing on the Angular side
Upload.upload({
url: '/api/FileStorage/AddContent' + location.search,
data: {file: files, year: vm.year }
})
And the WebApi side
var streamProvider = new CustomMultipartFileStreamProvider();
IEnumerable<HttpContent> parts = null;
Task.Factory
.StartNew(() => parts = Request.Content.ReadAsMultipartAsync(streamProvider).Result.Contents,
CancellationToken.None,
TaskCreationOptions.LongRunning, // guarantees separate thread
TaskScheduler.Default)
.Wait();
var customData = streamProvider.CustomData;
Here I am using a MultiStreamProvider to get the file, here is the meat of that provider
public override Task ExecutePostProcessingAsync()
{
foreach (var file in Contents)
{
var parameters = file.Headers.ContentDisposition.Parameters;
var filename = GetNameHeaderValue(parameters, "filename");
var year = GetNameHeaderValue(parameters, "year");
}
return base.ExecutePostProcessingAsync();
}
I am able to get filename without issue, but am never able to get the year. Here is the value in the debugger when I am looking at the parameters variable
As you can see, the name is "name" and the value is "year" when I would expect the name to be "year" and value to be "2016" or whatever I am passing in. What am I doing wrong here and how do I get the metadata included in the same call to the Api?

Answer 1

We use a similar approach with ng-file-upload and WebAPI. To get the values out of the form data, we weren't able to use GetNameHeaderValue. We had to do some manual parsing. We decided to use modified version of what was posted at http://conficient.wordpress.com/2013/07/22/async-file-uploads-with-mvc-webapi-and-bootstrap/ to dynamically take a form and unload it to a strongly-typed Model. But basically, here's what it does in the ExecutePostProcessingAsync method:
public override async Task ExecutePostProcessingAsync()
{
var formData = new FormCollection();
for (int index = 0; index < Contents.Count; index++)
{
ContentDispositionHeaderValue contentDisposition = headers.ContentDisposition;
if (contentDisposition != null)
{
HttpContent formContent = Contents[index];
string formFieldName = UnquoteToken(contentDisposition.Name) ?? String.Empty;
// Read the contents as string data and add to form data
string formFieldValue = await formContent.ReadAsStringAsync();
formData.Add(formFieldName, formFieldValue);
}
//For your case
var filename = formData["filename"];
var year = formData["year"];
This is the UnquoteToken method this uses:
private static string UnquoteToken(string token)
{
if (String.IsNullOrWhiteSpace(token))
{
return token;
}
if (token.StartsWith("\"", StringComparison.Ordinal) && token.EndsWith("\"", StringComparison.Ordinal) && token.Length > 1)
{
return token.Substring(1, token.Length - 2);
}
return token;
}