protected function getXML($force_cache_update)
{
$cache_key = $this->getCacheKey();
$expiry_key = $this->getCacheExpiryKey();
$expired = $force_cache_update || $this->app->getCacheValue($expiry_key);
if ($expired === false) {
// expiry key expired, check for updated content on Tumblr
$xml = $this->getTumblrXML();
if ($xml === false) {
// Tumblr API is down, try long cached value
$xml = $this->app->getCacheValue($cache_key);
if ($xml === false) {
// Tumblr API is down, but we have no cached value
$xml = '';
}
} else {
// update long cache with new Tumblr content
$this->app->addCacheValue($xml, $cache_key, null, 7200);
}
// update expiry cache value
$this->app->addCacheValue('1', $expiry_key, null, 300);
} else {
// expiry key not expired, check for long cached value
$xml = $this->app->getCacheValue($cache_key);
if ($xml === false) {
// long cached version expired or does not exist, check
// for content on Tumblr
$xml = $this->getTumblrXML();
if ($xml === false) {
// Tumblr API is down, but we have no cached value
$xml = '';
$this->app->deleteCacheValue($expiry_key);
} else {
// update long cache with new Tumblr content
$this->app->addCacheValue($xml, $cache_key, null, 7200);
}
}
}
return $xml;
}