How should I return a large text file using ServiceStack?

Question

I have a web service that needs to return a large text file for an AJAX call on the client. For starters, I have a valid path to the text file:

var fileName = <file on server>

I know the file name is valid, because I can open it on the server as a FileStream.

I have tried some of the different approaches recommended in ServiceStack and returning a stream, but I can't seem to get it to work.

What should I return? My best guess was:

var stream = File.Open(fileName, ...);
return HttpResult(stream, "text/plain"){ AllowPartialResponse = false };

But that doesn't work; the response is a simple JSON object. Using FileInfo with the asAttachment option didn't work either; it just returned a bunch of file information.

The goal is for the JavaScript client to be able to receive the content as a string:

api.getFile({...}).then( function (result) {
    // result has the file contents
}); 

What is the correct way to do this?

Update:

I ended up using this stream approach to get it working:

using( var fs = File.OpenRead( fileName ) )
{
    fs.CopyTo( Response.OutputStream );
}

I don't fully understand why some of the other approaches didn't work, but they appear to be related to 1) FileInfo and how it behaves on the server, 2) file permissions in my development environment, and 3) "partial content" problems and exceptions. File.Exists() returns false, but not in debug discusses one of the problems that was throwing me off.

Answer 1

I've just committed a Service that returns a text file and the HttpResult API's work as expected:

[Route("/textfile-test")]
public class TextFileTest
{
    public bool AsAttachment { get; set; }
}

public class MyServices : Service
{
    public object Any(TextFileTest request)
    {
        return new HttpResult(new FileInfo("~/textfile.txt".MapHostAbsolutePath()), 
            asAttachment:request.AsAttachment);
    }
}

Which you can test out with or without the asAttachment option:

• http://test.servicestack.net/textfile-test
• http://test.servicestack.net/textfile-test?asAttachment=true

You can also access the text file directly (i.e. without a Service):

• http://test.servicestack.net/textfile.txt

In addition, the different ways to return an Image response should also apply to text files as well.