class CacheExampleForm
Same name in other branches
- 8.x-1.x cache_example/src/Form/CacheExampleForm.php \Drupal\cache_example\Form\CacheExampleForm
- 4.0.x modules/cache_example/src/Form/CacheExampleForm.php \Drupal\cache_example\Form\CacheExampleForm
Form with examples on how to use cache.
Hierarchy
- class \Drupal\Core\Form\FormBase implements \Drupal\Core\Form\FormInterface, \Drupal\Core\DependencyInjection\ContainerInjectionInterface uses \Drupal\Core\DependencyInjection\DependencySerializationTrait, \Drupal\Core\Logger\LoggerChannelTrait, \Drupal\Core\Messenger\MessengerTrait, \Drupal\Core\Routing\RedirectDestinationTrait, \Drupal\Core\StringTranslation\StringTranslationTrait
- class \Drupal\cache_example\Form\CacheExampleForm extends \Drupal\Core\Form\FormBase
Expanded class hierarchy of CacheExampleForm
1 string reference to 'CacheExampleForm'
- cache_example.routing.yml in modules/
cache_example/ cache_example.routing.yml - modules/cache_example/cache_example.routing.yml
File
-
modules/
cache_example/ src/ Form/ CacheExampleForm.php, line 14
Namespace
Drupal\cache_example\FormView source
class CacheExampleForm extends FormBase {
/**
* The current user.
*
* @var \Drupal\Core\Session\AccountProxyInterface
*/
protected $currentUser;
/**
* The cache.default cache backend.
*
* @var \Drupal\Core\Cache\CacheBackendInterface
*/
protected $cacheBackend;
/**
* The date formatter service.
*
* @var \Drupal\Core\Datetime\DateFormatterInterface
*/
protected $dateFormatter;
/**
* The file system service.
*
* @var \Drupal\Core\File\FileSystemInterface
*/
protected $fileSystem;
/**
* {@inheritdoc}
*/
public static function create(ContainerInterface $container) {
// Forms that require a Drupal service or a custom service should access
// the service using dependency injection.
// @link https://www.drupal.org/node/2203931.
// Those services are passed in the $container through the static create
// method.
$form = new static();
$form->setRequestStack($container->get('request_stack'))
->setStringTranslation($container->get('string_translation'))
->setMessenger($container->get('messenger'));
$form->currentUser = $container->get('current_user');
$form->cacheBackend = $container->get('cache.default');
$form->dateFormatter = $container->get('date.formatter');
$form->fileSystem = $container->get('file_system');
return $form;
}
/**
* {@inheritdoc}
*/
public function getFormId() {
return 'cron_cache';
}
/**
* {@inheritdoc}
*/
public function buildForm(array $form, FormStateInterface $form_state) {
// Log execution time.
$start_time = microtime(TRUE);
// Try to load the files count from cache. This function will accept two
// arguments:
// - cache object name (cid)
// - cache bin, the (optional) cache bin (most often a database table) where
// the object is to be saved.
//
// cache_get() returns the cached object or FALSE if object does not exist.
if ($cache = $this->cacheBackend
->get('cache_example_files_count')) {
/*
* Get cached data. Complex data types will be unserialized automatically.
*/
$files_count = $cache->data;
}
else {
// If there was no cached data available we have to search filesystem.
// Recursively get all .PHP files from Drupal's core folder.
$files_count = count($this->fileSystem
->scanDirectory('core', '/.php/'));
// Since we have recalculated, we now need to store the new data into
// cache. Complex data types will be automatically serialized before
// being saved into cache.
// Here we use the default setting and create an unexpiring cache item.
// See below for an example that creates an expiring cache item.
$this->cacheBackend
->set('cache_example_files_count', $files_count, CacheBackendInterface::CACHE_PERMANENT);
}
$end_time = microtime(TRUE);
$duration = $end_time - $start_time;
// Format intro message.
$intro_message = '<p>' . $this->t("This example will search Drupal's core folder and display a count of the PHP files in it.") . ' ';
$intro_message .= $this->t('This can take a while, since there are a lot of files to be searched.') . ' ';
$intro_message .= $this->t('We will search filesystem just once and save output to the cache. We will use cached data for later requests.') . '</p>';
$intro_message .= '<p>' . $this->t('<a href="@url">Reload this page</a> to see cache in action.', [
'@url' => $this->getRequest()
->getRequestUri(),
]) . ' ';
$intro_message .= $this->t('You can use the button below to remove cached data.') . '</p>';
$form['file_search'] = [
'#type' => 'fieldset',
'#title' => $this->t('File search caching'),
];
$form['file_search']['introduction'] = [
'#markup' => $intro_message,
];
$color = empty($cache) ? 'red' : 'green';
$retrieval = empty($cache) ? $this->t('calculated by traversing the filesystem') : $this->t('retrieved from cache');
$form['file_search']['statistics'] = [
'#type' => 'item',
'#markup' => $this->t('%count files exist in this Drupal installation; @retrieval in @time ms. <br/>(Source: <span style="color:@color;">@source</span>)', [
'%count' => $files_count,
'@retrieval' => $retrieval,
'@time' => number_format($duration * 1000, 2),
'@color' => $color,
'@source' => empty($cache) ? $this->t('actual file search') : $this->t('cached'),
]),
];
$form['file_search']['remove_file_count'] = [
'#type' => 'submit',
'#submit' => [
'::expireFiles',
],
'#value' => $this->t('Explicitly remove cached file count'),
];
$form['expiration_demo'] = [
'#type' => 'fieldset',
'#title' => $this->t('Cache expiration settings'),
];
$form['expiration_demo']['explanation'] = [
'#markup' => $this->t('A cache item can be set as CACHE_PERMANENT, meaning that it will only be removed when explicitly cleared, or it can have an expiration time (a Unix timestamp).'),
];
$item = $this->cacheBackend
->get('cache_example_expiring_item', TRUE);
if ($item == FALSE) {
$item_status = $this->t('Cache item does not exist');
}
else {
$item_status = $item->valid ? $this->t('Cache item exists and is set to expire at %time', [
'%time' => $item->data,
]) : $this->t('Cache_item is invalid');
}
$form['expiration_demo']['current_status'] = [
'#type' => 'item',
'#title' => $this->t('Current status of cache item "cache_example_expiring_item"'),
'#markup' => $item_status,
];
$form['expiration_demo']['expiration'] = [
'#type' => 'select',
'#title' => $this->t('Time before cache expiration'),
'#options' => [
'never_remove' => $this->t('CACHE_PERMANENT'),
-10 => $this->t('Immediate expiration'),
10 => $this->t('10 seconds from form submission'),
60 => $this->t('1 minute from form submission'),
300 => $this->t('5 minutes from form submission'),
],
'#default_value' => -10,
'#description' => $this->t('Any cache item can be set to only expire when explicitly cleared, or to expire at a given time.'),
];
$form['expiration_demo']['create_cache_item'] = [
'#type' => 'submit',
'#value' => $this->t('Create a cache item with this expiration'),
'#submit' => [
'::createExpiringItem',
],
];
$form['cache_clearing'] = [
'#type' => 'fieldset',
'#title' => $this->t('Expire and remove options'),
'#description' => $this->t("We have APIs to expire cached items and also to just remove them. Unfortunately, they're all the same API, cache_clear_all"),
];
$form['cache_clearing']['cache_clear_type'] = [
'#type' => 'radios',
'#title' => $this->t('Type of cache clearing to do'),
'#options' => [
'expire' => $this->t('Remove items from the "cache" bin that have expired'),
'remove_all' => $this->t('Remove all items from the "cache" bin regardless of expiration'),
'remove_tag' => $this->t('Remove all items in the "cache" bin with the tag "cache_example" set to 1'),
],
'#default_value' => 'expire',
];
// Submit button to clear cached data.
$form['cache_clearing']['clear_expired'] = [
'#type' => 'submit',
'#value' => $this->t('Clear or expire cache'),
'#submit' => [
'::cacheClearing',
],
'#access' => $this->currentUser
->hasPermission('administer site configuration'),
];
return $form;
}
/**
* Submit handler that explicitly clears cache_example_files_count from cache.
*/
public function expireFiles($form, &$form_state) {
// Clear cached data. This function will delete cached object from cache
// bin.
//
// The first argument is cache id to be deleted. Since we've provided it
// explicitly, it will be removed whether or not it has an associated
// expiration time. The second argument (required here) is the cache bin.
// Using cache_clear_all() explicitly in this way
// forces removal of the cached item.
$this->cacheBackend
->delete('cache_example_files_count');
// Display message to the user.
$this->messenger()
->addMessage($this->t('Cached data key "cache_example_files_count" was cleared.'), 'status');
}
/**
* Submit handler to create a new cache item with specified expiration.
*/
public function createExpiringItem($form, &$form_state) {
$tags = [
'cache_example:1',
];
$interval = $form_state->getValue('expiration');
if ($interval == 'never_remove') {
$expiration = CacheBackendInterface::CACHE_PERMANENT;
$expiration_friendly = $this->t('Never expires');
}
else {
$expiration = time() + $interval;
$expiration_friendly = $this->dateFormatter
->format($expiration);
}
// Set the expiration to the actual Unix timestamp of the end of the
// required interval. Also add a tag to it to be able to clear caches more
// precise.
$this->cacheBackend
->set('cache_example_expiring_item', $expiration_friendly, $expiration, $tags);
$this->messenger()
->addMessage($this->t('cache_example_expiring_item was set to expire at %time', [
'%time' => $expiration_friendly,
]));
}
/**
* Submit handler to demonstrate the various uses of cache_clear_all().
*/
public function cacheClearing($form, &$form_state) {
switch ($form_state->getValue('cache_clear_type')) {
case 'expire':
// Here we'll remove all cache keys in the 'cache' bin that have
// expired.
$this->cacheBackend
->garbageCollection();
$this->messenger()
->addMessage($this->t('\\Drupal::cache()->garbageCollection() was called, removing any expired cache items.'));
break;
case 'remove_all':
// This removes all keys in a bin using a super-wildcard. This
// has nothing to do with expiration. It's just brute-force removal.
$this->cacheBackend
->deleteAll();
$this->messenger()
->addMessage($this->t('ALL entries in the "cache" bin were removed with \\Drupal::cache()->deleteAll().'));
break;
case 'remove_tag':
// This removes cache entries with the tag "cache_example" set to 1 in
// the "cache".
$tags = [
'cache_example:1',
];
Cache::invalidateTags($tags);
$this->messenger()
->addMessage($this->t('Cache entries with the tag "cache_example" set to 1 in the "cache" bin were invalidated with \\Drupal\\Core\\Cache\\Cache::invalidateTags($tags).'));
break;
}
}
/**
* {@inheritdoc}
*/
public function submitForm(array &$form, FormStateInterface $form_state) {
}
}
Members
Title Sort descending | Modifiers | Object type | Summary | Overriden Title | Overrides |
---|---|---|---|---|---|
CacheExampleForm::$cacheBackend | protected | property | The cache.default cache backend. | ||
CacheExampleForm::$currentUser | protected | property | The current user. | ||
CacheExampleForm::$dateFormatter | protected | property | The date formatter service. | ||
CacheExampleForm::$fileSystem | protected | property | The file system service. | ||
CacheExampleForm::buildForm | public | function | Form constructor. | Overrides FormInterface::buildForm | |
CacheExampleForm::cacheClearing | public | function | Submit handler to demonstrate the various uses of cache_clear_all(). | ||
CacheExampleForm::create | public static | function | Instantiates a new instance of this class. | Overrides FormBase::create | |
CacheExampleForm::createExpiringItem | public | function | Submit handler to create a new cache item with specified expiration. | ||
CacheExampleForm::expireFiles | public | function | Submit handler that explicitly clears cache_example_files_count from cache. | ||
CacheExampleForm::getFormId | public | function | Returns a unique string identifying the form. | Overrides FormInterface::getFormId | |
CacheExampleForm::submitForm | public | function | Form submission handler. | Overrides FormInterface::submitForm | |
DependencySerializationTrait::$_entityStorages | protected | property | |||
DependencySerializationTrait::$_serviceIds | protected | property | |||
DependencySerializationTrait::__sleep | public | function | 1 | ||
DependencySerializationTrait::__wakeup | public | function | 2 | ||
FormBase::$configFactory | protected | property | The config factory. | 3 | |
FormBase::$requestStack | protected | property | The request stack. | 1 | |
FormBase::$routeMatch | protected | property | The route match. | ||
FormBase::config | protected | function | Retrieves a configuration object. | ||
FormBase::configFactory | protected | function | Gets the config factory for this form. | 3 | |
FormBase::container | private | function | Returns the service container. | ||
FormBase::currentUser | protected | function | Gets the current user. | ||
FormBase::getRequest | protected | function | Gets the request object. | ||
FormBase::getRouteMatch | protected | function | Gets the route match. | ||
FormBase::logger | protected | function | Gets the logger for a specific channel. | ||
FormBase::redirect | protected | function | Returns a redirect response object for the specified route. | ||
FormBase::resetConfigFactory | public | function | Resets the configuration factory. | ||
FormBase::setConfigFactory | public | function | Sets the config factory for this form. | ||
FormBase::setRequestStack | public | function | Sets the request stack object to use. | ||
FormBase::validateForm | public | function | Form validation handler. | Overrides FormInterface::validateForm | 73 |
LoggerChannelTrait::$loggerFactory | protected | property | The logger channel factory service. | ||
LoggerChannelTrait::getLogger | protected | function | Gets the logger for a specific channel. | ||
LoggerChannelTrait::setLoggerFactory | public | function | Injects the logger channel factory. | ||
MessengerTrait::$messenger | protected | property | The messenger. | 17 | |
MessengerTrait::messenger | public | function | Gets the messenger. | 17 | |
MessengerTrait::setMessenger | public | function | Sets the messenger. | ||
RedirectDestinationTrait::$redirectDestination | protected | property | The redirect destination service. | 1 | |
RedirectDestinationTrait::getDestinationArray | protected | function | Prepares a 'destination' URL query parameter for use with \Drupal\Core\Url. | ||
RedirectDestinationTrait::getRedirectDestination | protected | function | Returns the redirect destination service. | ||
RedirectDestinationTrait::setRedirectDestination | public | function | Sets the redirect destination service. | ||
StringTranslationTrait::$stringTranslation | protected | property | The string translation service. | 3 | |
StringTranslationTrait::formatPlural | protected | function | Formats a string containing a count of items. | ||
StringTranslationTrait::getNumberOfPlurals | protected | function | Returns the number of plurals supported by a given language. | ||
StringTranslationTrait::getStringTranslation | protected | function | Gets the string translation service. | ||
StringTranslationTrait::setStringTranslation | public | function | Sets the string translation service to use. | 2 | |
StringTranslationTrait::t | protected | function | Translates a string to the current language or to a given language. |