private static bool CheckModified(ResultExecutingContext context, IConditionalRequestMetadata metadata)
{
bool modified = true;
HttpRequestConditions requestConditions = context.HttpContext.Request.GetRequestConditions();
if ((requestConditions.IfNoneMatch != null) && requestConditions.IfNoneMatch.Any())
{
if (!String.IsNullOrWhiteSpace(metadata.EntityTag) && requestConditions.IfNoneMatch.Contains(metadata.EntityTag))
{
modified = false;
context.Result = new StatusCodeResult(StatusCodes.Status304NotModified);
}
}
else if (requestConditions.IfModifiedSince.HasValue && metadata.LastModified.HasValue)
{
DateTimeOffset lastModified = metadata.LastModified.Value.AddTicks(-(metadata.LastModified.Value.Ticks % TimeSpan.TicksPerSecond));
if (lastModified <= requestConditions.IfModifiedSince.Value)
{
modified = false;
context.Result = new StatusCodeResult(StatusCodes.Status304NotModified);
}
}
return(modified);
}
public void OnResultExecuting(ResultExecutingContext context)
{
IConditionalRequestMetadata metadata = (context.Result as ObjectResult)?.Value as IConditionalRequestMetadata;
if (metadata != null)
{
if (CheckModified(context, metadata))
{
SetConditionalMetadataHeaders(context, metadata);
}
}
}
private static void SetConditionalMetadataHeaders(ResultExecutingContext context, IConditionalRequestMetadata metadata)
{
ResponseHeaders responseHeaders = context.HttpContext.Response.GetTypedHeaders();
if (!String.IsNullOrWhiteSpace(metadata.EntityTag))
{
responseHeaders.ETag = new EntityTagHeaderValue(metadata.EntityTag, true);
}
if (metadata.LastModified.HasValue)
{
responseHeaders.LastModified = metadata.LastModified.Value;
}
}
