class PagerExamplePage in Examples for Developers 8

Same name and namespace in other branches

3.x modules/pager_example/src/Controller/PagerExamplePage.php \Drupal\pager_example\Controller\PagerExamplePage

Controller for pager_example.page route.

This is an example describing how a module can implement a pager in order to reduce the number of output rows to the screen and allow a user to scroll through multiple screens of output.

Hierarchy

class \Drupal\Core\Controller\ControllerBase implements ContainerInjectionInterface uses LoggerChannelTrait, MessengerTrait, LinkGeneratorTrait, RedirectDestinationTrait, UrlGeneratorTrait, StringTranslationTrait
- class \Drupal\pager_example\Controller\PagerExamplePage

Expanded class hierarchy of PagerExamplePage

File

pager_example/src/Controller/PagerExamplePage.php, line 18

Namespace

Drupal\pager_example\Controller

View source

class PagerExamplePage extends ControllerBase {

  /**
   * Entity storage for node entities.
   *
   * @var \Drupal\Core\Entity\EntityStorageInterface
   */
  protected $nodeStorage;

  /**
   * The current user.
   *
   * @var \Drupal\Core\Session\AccountInterface
   */
  protected $currentUser;

  /**
   * PagerExamplePage constructor.
   *
   * @param \Drupal\Core\Entity\EntityStorageInterface $node_storage
   *   Entity storage for node entities.
   * @param \Drupal\Core\Session\AccountInterface $current_user
   *   The current user.
   */
  public function __construct(EntityStorageInterface $node_storage, AccountInterface $current_user) {
    $this->nodeStorage = $node_storage;
    $this->currentUser = $current_user;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    $controller = new static($container
      ->get('entity_type.manager')
      ->getStorage('node'), $container
      ->get('current_user'));
    $controller
      ->setStringTranslation($container
      ->get('string_translation'));
    return $controller;
  }

  /**
   * Content callback for the pager_example.page route.
   */
  public function getContent() {

    // First we'll tell the user what's going on. This content can be found
    // in the twig template file: templates/description.html.twig. It will be
    // inserted by the theming function pager_example_description().
    $build = [
      'description' => [
        '#theme' => 'pager_example_description',
        '#description' => $this
          ->t('description'),
        '#attributes' => [],
      ],
    ];

    // Ensure that this page's cache is invalidated when nodes have been
    // published, unpublished, added or deleted; and when user permissions
    // change.
    $build['#cache']['tags'][] = 'node_list';
    $build['#cache']['contexts'][] = 'user.permissions';

    // Now we want to get our tabular data. We select nodes from node storage
    // limited by 2 per page and sort by nid DESC because we want to show newest
    // node first. Additionally, we check that the user has permission to
    // view the node.
    $query = $this->nodeStorage
      ->getQuery()
      ->sort('nid', 'DESC')
      ->addTag('node_access')
      ->pager(2);

    // The node_access tag does not trigger a check on whether a user has the
    // ability to view unpublished content. The 'bypass node access' permission
    // is really more than we need. But, there is no separate permission for
    // viewing unpublished content. There is a permission to 'view own
    // unpublished content', but we don't have a good way of using that in this
    // query. So, unfortunately this query will incorrectly eliminate even those
    // unpublished nodes that the user may, in fact, be allowed to view.
    if (!$this->currentUser
      ->hasPermission('bypass node access')) {
      $query
        ->condition('status', 1);
    }
    $entity_ids = $query
      ->execute();
    $nodes = $this->nodeStorage
      ->loadMultiple($entity_ids);

    // We are going to output the results in a table so we set up the rows.
    $rows = [];
    foreach ($nodes as $node) {

      // There are certain things (besides unpublished nodes) that the
      // node_access tag won't prevent from being seen. The only way to get at
      // those is by explicitly checking for (view) access on a node-by-node
      // basis. In order to prevent the pager from looking strange, we will
      // "mask" these nodes that should not be accessible. If we don't do this
      // masking, it's possible that we'd have lots of pages that don't show any
      // content.
      $rows[] = [
        'nid' => $node
          ->access('view') ? $node
          ->id() : $this
          ->t('XXXXXX'),
        'title' => $node
          ->access('view') ? $node
          ->getTitle() : $this
          ->t('Redacted'),
      ];
    }

    // Build a render array which will be themed as a table with a pager.
    $build['pager_example'] = [
      '#type' => 'table',
      '#header' => [
        $this
          ->t('NID'),
        $this
          ->t('Title'),
      ],
      '#rows' => $rows,
      '#empty' => $this
        ->t('There are no nodes to display. Please <a href=":url">create a node</a>.', [
        ':url' => Url::fromRoute('node.add', [
          'node_type' => 'page',
        ])
          ->toString(),
      ]),
    ];

    // Add our pager element so the user can choose which pagination to see.
    // This will add a '?page=1' fragment to the links to subsequent pages.
    $build['pager'] = [
      '#type' => 'pager',
      '#weight' => 10,
    ];
    return $build;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
ControllerBase::$configFactory	protected	property	The configuration factory.
ControllerBase::$entityFormBuilder	protected	property	The entity form builder.
ControllerBase::$entityManager	protected	property	The entity manager.
ControllerBase::$entityTypeManager	protected	property	The entity type manager.
ControllerBase::$formBuilder	protected	property	The form builder.	2
ControllerBase::$keyValue	protected	property	The key-value storage.	1
ControllerBase::$languageManager	protected	property	The language manager.	1
ControllerBase::$moduleHandler	protected	property	The module handler.	2
ControllerBase::$stateService	protected	property	The state service.
ControllerBase::cache	protected	function	Returns the requested cache bin.
ControllerBase::config	protected	function	Retrieves a configuration object.
ControllerBase::container	private	function	Returns the service container.
ControllerBase::currentUser	protected	function	Returns the current user.	1
ControllerBase::entityFormBuilder	protected	function	Retrieves the entity form builder.
ControllerBase::entityManager Deprecated	protected	function	Retrieves the entity manager service.
ControllerBase::entityTypeManager	protected	function	Retrieves the entity type manager.
ControllerBase::formBuilder	protected	function	Returns the form builder service.	2
ControllerBase::keyValue	protected	function	Returns a key/value storage collection.	1
ControllerBase::languageManager	protected	function	Returns the language manager service.	1
ControllerBase::moduleHandler	protected	function	Returns the module handler.	2
ControllerBase::redirect	protected	function	Returns a redirect response object for the specified route. Overrides UrlGeneratorTrait::redirect
ControllerBase::state	protected	function	Returns the state storage service.
LinkGeneratorTrait::$linkGenerator	protected	property	The link generator.	1
LinkGeneratorTrait::getLinkGenerator Deprecated	protected	function	Returns the link generator.
LinkGeneratorTrait::l Deprecated	protected	function	Renders a link to a route given a route name and its parameters.
LinkGeneratorTrait::setLinkGenerator Deprecated	public	function	Sets the link generator service.
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.	29
MessengerTrait::messenger	public	function	Gets the messenger.	29
MessengerTrait::setMessenger	public	function	Sets the messenger.
PagerExamplePage::$currentUser	protected	property	The current user. Overrides ControllerBase::$currentUser
PagerExamplePage::$nodeStorage	protected	property	Entity storage for node entities.
PagerExamplePage::create	public static	function	Instantiates a new instance of this class. Overrides ControllerBase::create
PagerExamplePage::getContent	public	function	Content callback for the pager_example.page route.
PagerExamplePage::__construct	public	function	PagerExamplePage constructor.
RedirectDestinationTrait::$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::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.
UrlGeneratorTrait::$urlGenerator	protected	property	The url generator.
UrlGeneratorTrait::getUrlGenerator Deprecated	protected	function	Returns the URL generator service.
UrlGeneratorTrait::setUrlGenerator Deprecated	public	function	Sets the URL generator service.
UrlGeneratorTrait::url Deprecated	protected	function	Generates a URL or path for a specific route based on the given parameters.

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class PagerExamplePage in Examples for Developers 8

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