/**
* Determine if resource was NOT modified
* since requester's last check
*
* For Concurrency Control (Lost Update Problem)
* Uses `If-Match` and/or `If-Unmodified-Since`
*/
public function wasNotModified(ResourceInterface $resource)
{
/*
* Unlike If-None-Match, the spec on If-Match
* does NOT say if If-Unmodified-Since
* should be ignored if an ETag was given via
* If-Match.
*
* We'll assume the same behaviour anyway.
*/
$usesEtags = false;
// First, ETag Validation
$etag = str_replace('"', '', $this->getHeader('if-match'));
if ($etag) {
$usesEtags = true;
if ($etag !== $resource->getEtag()) {
return false;
}
}
// Second, Modification Date Validation
$ifUnmodifiedSince = $this->getHeader('if-unmodified-since');
if ($ifUnmodifiedSince && $usesEtags === false) {
if (strtotime($ifUnmodifiedSince) < $resource->getLastUpdated()->getTimestamp()) {
return false;
}
}
return true;
}
/**
* Set cache settings (simple for now)
*
* @param Fideloper\ResourceCache\Resource\ResourceInterface
* @param Symfony\Component\HttpFoundation\Response
* @return Symfony\Component\HttpFoundation\Response
*/
protected function setCache(ResourceInterface $resource, HttpResponse $response)
{
$response->setCache(array('etag' => $resource->getEtag(), 'last_modified' => $resource->getLastUpdated()));
return $response;
}