/// <summary>
/// Get a file for a request. If the
/// </summary>
/// <param name="request">The request.</param>
/// <param name="imageIdRef">The image identifier reference.</param>
/// <param name="generateEtagFn">The generate e-tag function.</param>
/// <returns>
/// The file response or a NotModified response if the e-tag matches.
/// </returns>
public static HttpResponseMessage GetFileForRequest(HttpRequestMessage request, ERM.EntityRef imageIdRef, Func <ERM.EntityRef, string> generateEtagFn)
{
string etag = generateEtagFn(imageIdRef);
// If the request contains the same e-tag then return a not modified
if (request.Headers.IfNoneMatch != null &&
request.Headers.IfNoneMatch.Any(et => et.Tag == etag))
{
var notModifiedResponse = new HttpResponseMessage(HttpStatusCode.NotModified);
notModifiedResponse.Headers.ETag = new EntityTagHeaderValue(etag, false);
return(notModifiedResponse);
}
// Return the image
var response = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StreamContent(FileRepositoryHelper.GetFileDataStreamForEntity(imageIdRef))
};
response.Headers.ETag = new EntityTagHeaderValue(etag, false);
response.Headers.CacheControl = new CacheControlHeaderValue
{
MustRevalidate = true,
MaxAge = new TimeSpan(0)
};
// Yuck. You gotta do what you gotta do.
bool isIosDevice = false;
if (request.Headers.UserAgent != null)
{
isIosDevice = request.Headers.UserAgent.Any(ua => IosMobileRegex.IsMatch(ua.ToString()));
}
string contentType = string.Empty;
// Note: We are not setting the content length because the CompressionHandler will compress the stream.
// Specifying the length here will cause the browser to hang as the actual data it
// receives (as it is compressed) will be less than the specified content length.
FileDetails dbFileType = FileRepositoryHelper.GetStreamContentType(imageIdRef);
if (dbFileType != null)
{
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = dbFileType.Filename
};
// Found that specifying specific mime types on IOS mobile
// causes safari to raise errors.
// However, found that on Android the download
// manager requires the mime type so that the downloaded
// file can be opened by tapping.
if (!isIosDevice)
{
if (!string.IsNullOrWhiteSpace(dbFileType.ContentType))
{
contentType = dbFileType.ContentType;
}
else
{
// Attempt to get a mime type from the file name
if (!string.IsNullOrWhiteSpace(dbFileType.Filename))
{
contentType = MimeMapping.GetMimeMapping(dbFileType.Filename);
}
}
}
}
// If we don't have a content type, fallback to the generic one.
if (string.IsNullOrWhiteSpace(contentType))
{
contentType = "application/octet-stream";
}
response.Content.Headers.ContentType = new MediaTypeHeaderValue(contentType);
return(response);
}
