TPageStateFormatter is a utility class to transform the page state
into and from a string that can be properly saved in persistent storage.
Depending on the {@link TPage::getEnableStateValidation() EnableStateValidation}
and {@link TPage::getEnableStateEncryption() EnableStateEncryption},
TPageStateFormatter may do HMAC validation and encryption to prevent
the state data from being tampered or viewed.
The private keys and hashing/encryption methods are determined by
{@link TApplication::getSecurityManager() SecurityManager}.
/**
* Loads page state from hidden fields.
* @return mixed the restored state
* @throws THttpException if page state is corrupted
*/
public function load()
{
if (($data = TPageStateFormatter::unserialize($this->_page, $this->_page->getRequestClientState())) !== null) {
return $data;
} else {
throw new THttpException(400, 'pagestatepersister_pagestate_corrupted');
}
}
/**
* Loads page state from session.
* @return mixed the restored state
* @throws THttpException if page state is corrupted
*/
public function load()
{
if (($timestamp = TPageStateFormatter::unserialize($this->_page, $this->_page->getRequestClientState())) !== null) {
$session = $this->_page->getSession();
$session->open();
$key = self::STATE_SESSION_KEY . $timestamp;
if (($data = $session->itemAt($key)) !== null) {
return unserialize($data);
}
}
throw new THttpException(400, 'sessionpagestatepersister_pagestate_corrupted');
}
/**
* Loads page state from cache.
* @return mixed the restored state
* @throws THttpException if page state is corrupted
*/
public function load()
{
if (($timestamp = TPageStateFormatter::unserialize($this->_page, $this->_page->getRequestClientState())) !== null) {
$key = $this->calculateKey($timestamp);
if (($data = $this->getCache()->get($key)) !== false) {
return $data;
}
}
throw new THttpException(400, 'cachepagestatepersister_pagestate_corrupted');
}