public async Task<bool> CheckRepresentationExistsAsync(
Controller controller,
string representationId)
{
if (controller == null)
{
throw new ArgumentNullException(nameof(controller));
}
if (string.IsNullOrWhiteSpace(representationId))
{
throw new ArgumentNullException(nameof(representationId));
}
var concatenatedEtags = controller.GetIfMatch();
var unmodifiedSince = controller.GetUnmodifiedSince();
var checkDateCallback = new Func<DateTime, ConcurrentObject, bool>((d, c) =>
{
return c.DateTime <= d;
});
var checkEtagCorrectCallback = new Func<ConcurrentObject, List<EntityTagHeaderValue>, bool>((c, etags) =>
{
return etags.Any(e =>
{
if (e.IsWeak)
{
// Weak etag
if (c.Etag.Contains(e.Tag))
{
return true;
}
}
else
{
if (e.Tag == c.Etag)
{
return true;
}
}
return false;
});
});
return await ContinueExecution(concatenatedEtags, unmodifiedSince, representationId, checkDateCallback, checkEtagCorrectCallback);
}