Why is IE ignoring my attachment filename content-disposition? - angularjs

Question

I'm using ASP.NET Web API targeting the 4.5.2 framework and am trying to push out a CSV file generated by exporting data from a table. In Firefox and Chrome, everything works as expected, but with IE (I'm testing with 11), the filename is being ignored and IE is using the URL instead (with no extension). What am I doing wrong and how can I get around it?
Here's my controller method:
[HttpGet]
public HttpResponseMessage ExportToCSV([FromUri]DistributionSearchCriteria criteria)
{
// This creates the csv in the temp folder and returns the temp file name
var file = _repository.ExportToCSV(criteria);
// This FileHttpResponseMessage is a custom type which just deletes the temp file in dispose
var result = new FileHttpResponseMessage(file, HttpStatusCode.OK)
{
Content = new StreamContent(File.OpenRead(file))
};
result.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
{
FileName = "Distributions.csv"
};
result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
return result;
}
Here's the custom FileHttpResponseMessage
public class FileHttpResponseMessage : HttpResponseMessage
{
private string _filePath;
public FileHttpResponseMessage(string filePath, HttpStatusCode statusCode) : base(statusCode)
{
_filePath = filePath;
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
if (disposing)
{
Content.Dispose();
if (File.Exists(_filePath))
{
try
{
System.Diagnostics.Debug.WriteLine("Deleting {0}", (object)_filePath);
File.Delete(_filePath);
System.Diagnostics.Debug.WriteLine("{0} deleted", (object)_filePath);
}
catch
{
System.Diagnostics.Debug.WriteLine("Error Deleting {0}", (object)_filePath);
}
}
}
}
}
and these are my two JavaScript methods in my AngularJS controller which launch the downloads:
vm.exportToCSV = function () {
var params = $httpParamSerializer(vm.searchCriteria);
$window.open(apiBase + 'Distribution/ExportToCSV?' + params, '_blank');
};
vm.exportAllToCSV = function () {
$window.open(apiBase + 'Distribution/ExportToCSV', '_blank');
};
From what I've read in other questions... setting the attachment; filename= should've been sufficient for IE. IE is prompting for a filename of "ExportToCSV".
I've also tried appending a bogus parameter like ?/distribution.csv and it changed the download filename but instead of distribution.csv it replaced the . with _ so the result was distribution_csv. Oh the pains of IE.
Update 1:
I've created a separate project to address only this issue and come up with specific workarounds. I've tried with and without quotes around the filename but I'm still no difference:
Update 2:
So I thought I would attempt to be "clever" and try to create a custom HTTP Handler for files with an extension:
Web.config
<!-- Route all files through asp -->
<modules runAllManagedModulesForAllRequests="true" />
<!-- Route all files through asp -->
<add name="FileDownloadHandler" path="/api/File/test.csv" verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0"/>
WebApiConfig.cs
config.Routes.MapHttpRoute(
name:"download",
routeTemplate: "api/File/test.csv",
defaults: new { controller = "File", action = "Get" }
);
as expected it used the test.csv but it replaced the . with _ resulting in a test_csv extensionless download.

Answer 1

This is the weirdest bug I've ever ran into. I'm not sure whether to attribute it to my anitvirus or not, but my CPU recently maxed out at 100% as a result of McAFEE going bananas and bringing my system to a crawl. As a result, I rebooted my machine. Now Internet Explorer is working as expected! I never would've guessed... I was beginning to question everything I thought I knew...
Moral of the story: