public async Task <IActionResult> GetSyndicationFeed([FromRoute] string controller,
[FromHeader(Name = Constants.HeaderNames.Accept)]
string contentType, [FromFilter] Encoding encoding, [FromRoute] string ns, [FromRoute] ulong rs,
[FromQuery(Name = "q")] string query = default)
{
var mediaType = contentType?.ToLowerInvariant().Trim();
var charset = encoding.WebName;
var queryUrl = Request.GetEncodedUrl();
var cacheKey = $"{mediaType}:{charset}:{queryUrl}";
if (!Request.IsContentStale(cacheKey, _feeds, out var stream, out var lastModified, out var result))
{
return(result);
}
if (stream != default || _feeds.TryGetValue(cacheKey, out stream))
{
return(ServeFeed(cacheKey, stream, mediaType, charset, lastModified));
}
var(records, _) = await QueryAsync(controller, ns, rs, query, CancellationToken);
if (!SyndicationGenerator.TryBuildFeedAsync(queryUrl, ns, rs, records, mediaType, encoding, out stream,
out lastModified))
{
return(new UnsupportedMediaTypeResult());
}
_feeds.Set(cacheKey, stream);
_feeds.Set($"{cacheKey}:{HeaderNames.LastModified}", lastModified);
return(ServeFeed(cacheKey, stream, mediaType, charset, lastModified));
}
