NodeGrantDatabaseStorage.php in Drupal 8

Namespace

Drupal\node

File

core/modules/node/src/NodeGrantDatabaseStorage.php

<?php

namespace Drupal\node;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Database\Connection;
use Drupal\Core\Database\Query\SelectInterface;
use Drupal\Core\Database\Query\Condition;
use Drupal\Core\Extension\ModuleHandlerInterface;
use Drupal\Core\Language\LanguageManagerInterface;
use Drupal\Core\Session\AccountInterface;

/**
 * Defines a storage handler class that handles the node grants system.
 *
 * This is used to build node query access.
 *
 * @ingroup node_access
 */
class NodeGrantDatabaseStorage implements NodeGrantDatabaseStorageInterface {

  /**
   * The database connection.
   *
   * @var \Drupal\Core\Database\Connection
   */
  protected $database;

  /**
   * The module handler.
   *
   * @var \Drupal\Core\Extension\ModuleHandlerInterface
   */
  protected $moduleHandler;

  /**
   * The language manager.
   *
   * @var \Drupal\Core\Language\LanguageManagerInterface
   */
  protected $languageManager;

  /**
   * Constructs a NodeGrantDatabaseStorage object.
   *
   * @param \Drupal\Core\Database\Connection $database
   *   The database connection.
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   *   The module handler.
   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
   *   The language manager.
   */
  public function __construct(Connection $database, ModuleHandlerInterface $module_handler, LanguageManagerInterface $language_manager) {
    $this->database = $database;
    $this->moduleHandler = $module_handler;
    $this->languageManager = $language_manager;
  }

  /**
   * {@inheritdoc}
   */
  public function access(NodeInterface $node, $operation, AccountInterface $account) {

    // Grants only support these operations.
    if (!in_array($operation, [
      'view',
      'update',
      'delete',
    ])) {
      return AccessResult::neutral();
    }

    // If no module implements the hook or the node does not have an id there is
    // no point in querying the database for access grants.
    if (!$this->moduleHandler
      ->getImplementations('node_grants') || !$node
      ->id()) {

      // Return the equivalent of the default grant, defined by
      // self::writeDefault().
      if ($operation === 'view') {
        return AccessResult::allowedIf($node
          ->isPublished());
      }
      else {
        return AccessResult::neutral();
      }
    }

    // Check the database for potential access grants.
    $query = $this->database
      ->select('node_access');
    $query
      ->addExpression('1');

    // Only interested for granting in the current operation.
    $query
      ->condition('grant_' . $operation, 1, '>=');

    // Check for grants for this node and the correct langcode.
    $nids = $query
      ->andConditionGroup()
      ->condition('nid', $node
      ->id())
      ->condition('langcode', $node
      ->language()
      ->getId());

    // If the node is published, also take the default grant into account. The
    // default is saved with a node ID of 0.
    $status = $node
      ->isPublished();
    if ($status) {
      $nids = $query
        ->orConditionGroup()
        ->condition($nids)
        ->condition('nid', 0);
    }
    $query
      ->condition($nids);
    $query
      ->range(0, 1);
    $grants = static::buildGrantsQueryCondition(node_access_grants($operation, $account));
    if (count($grants) > 0) {
      $query
        ->condition($grants);
    }

    // Only the 'view' node grant can currently be cached; the others currently
    // don't have any cacheability metadata. Hopefully, we can add that in the
    // future, which would allow this access check result to be cacheable in all
    // cases. For now, this must remain marked as uncacheable, even when it is
    // theoretically cacheable, because we don't have the necessary metadata to
    // know it for a fact.
    $set_cacheability = function (AccessResult $access_result) use ($operation) {
      $access_result
        ->addCacheContexts([
        'user.node_grants:' . $operation,
      ]);
      if ($operation !== 'view') {
        $access_result
          ->setCacheMaxAge(0);
      }
      return $access_result;
    };
    if ($query
      ->execute()
      ->fetchField()) {
      return $set_cacheability(AccessResult::allowed());
    }
    else {
      return $set_cacheability(AccessResult::neutral());
    }
  }

  /**
   * {@inheritdoc}
   */
  public function checkAll(AccountInterface $account) {
    $query = $this->database
      ->select('node_access');
    $query
      ->addExpression('COUNT(*)');
    $query
      ->condition('nid', 0)
      ->condition('grant_view', 1, '>=');
    $grants = static::buildGrantsQueryCondition(node_access_grants('view', $account));
    if (count($grants) > 0) {
      $query
        ->condition($grants);
    }
    return $query
      ->execute()
      ->fetchField();
  }

  /**
   * {@inheritdoc}
   */
  public function alterQuery($query, array $tables, $op, AccountInterface $account, $base_table) {
    if (!($langcode = $query
      ->getMetaData('langcode'))) {
      $langcode = FALSE;
    }

    // Find all instances of the base table being joined -- could appear
    // more than once in the query, and could be aliased. Join each one to
    // the node_access table.
    $grants = node_access_grants($op, $account);

    // If any grant exists for the specified user, then user has access to the
    // node for the specified operation.
    $grant_conditions = static::buildGrantsQueryCondition($grants);
    $grants_exist = count($grant_conditions
      ->conditions()) > 0;
    $is_multilingual = \Drupal::languageManager()
      ->isMultilingual();
    foreach ($tables as $nalias => $tableinfo) {
      $table = $tableinfo['table'];
      if (!$table instanceof SelectInterface && $table == $base_table) {

        // Set the subquery.
        $subquery = $this->database
          ->select('node_access', 'na')
          ->fields('na', [
          'nid',
        ]);

        // Attach conditions to the sub-query for nodes.
        if ($grants_exist) {
          $subquery
            ->condition($grant_conditions);
        }
        $subquery
          ->condition('na.grant_' . $op, 1, '>=');

        // Add langcode-based filtering if this is a multilingual site.
        if ($is_multilingual) {

          // If no specific langcode to check for is given, use the grant entry
          // which is set as a fallback.
          // If a specific langcode is given, use the grant entry for it.
          if ($langcode === FALSE) {
            $subquery
              ->condition('na.fallback', 1, '=');
          }
          else {
            $subquery
              ->condition('na.langcode', $langcode, '=');
          }
        }
        $field = 'nid';

        // Now handle entities.
        $subquery
          ->where("{$nalias}.{$field} = na.nid");
        $query
          ->exists($subquery);
      }
    }
  }

  /**
   * {@inheritdoc}
   */
  public function write(NodeInterface $node, array $grants, $realm = NULL, $delete = TRUE) {
    if ($delete) {
      $query = $this->database
        ->delete('node_access')
        ->condition('nid', $node
        ->id());
      if ($realm) {
        $query
          ->condition('realm', [
          $realm,
          'all',
        ], 'IN');
      }
      $query
        ->execute();
    }

    // Only perform work when node_access modules are active.
    if (!empty($grants) && count($this->moduleHandler
      ->getImplementations('node_grants'))) {
      $query = $this->database
        ->insert('node_access')
        ->fields([
        'nid',
        'langcode',
        'fallback',
        'realm',
        'gid',
        'grant_view',
        'grant_update',
        'grant_delete',
      ]);

      // If we have defined a granted langcode, use it. But if not, add a grant
      // for every language this node is translated to.
      $fallback_langcode = $node
        ->getUntranslated()
        ->language()
        ->getId();
      foreach ($grants as $grant) {
        if ($realm && $realm != $grant['realm']) {
          continue;
        }
        if (isset($grant['langcode'])) {
          $grant_languages = [
            $grant['langcode'] => $this->languageManager
              ->getLanguage($grant['langcode']),
          ];
        }
        else {
          $grant_languages = $node
            ->getTranslationLanguages(TRUE);
        }
        foreach ($grant_languages as $grant_langcode => $grant_language) {

          // Only write grants; denies are implicit.
          if ($grant['grant_view'] || $grant['grant_update'] || $grant['grant_delete']) {
            $grant['nid'] = $node
              ->id();
            $grant['langcode'] = $grant_langcode;

            // The record with the original langcode is used as the fallback.
            if ($grant['langcode'] == $fallback_langcode) {
              $grant['fallback'] = 1;
            }
            else {
              $grant['fallback'] = 0;
            }
            $query
              ->values($grant);
          }
        }
      }
      $query
        ->execute();
    }
  }

  /**
   * {@inheritdoc}
   */
  public function delete() {
    $this->database
      ->truncate('node_access')
      ->execute();
  }

  /**
   * {@inheritdoc}
   */
  public function writeDefault() {
    $this->database
      ->insert('node_access')
      ->fields([
      'nid' => 0,
      'realm' => 'all',
      'gid' => 0,
      'grant_view' => 1,
      'grant_update' => 0,
      'grant_delete' => 0,
    ])
      ->execute();
  }

  /**
   * {@inheritdoc}
   */
  public function count() {
    return $this->database
      ->query('SELECT COUNT(*) FROM {node_access}')
      ->fetchField();
  }

  /**
   * {@inheritdoc}
   */
  public function deleteNodeRecords(array $nids) {
    $this->database
      ->delete('node_access')
      ->condition('nid', $nids, 'IN')
      ->execute();
  }

  /**
   * Creates a query condition from an array of node access grants.
   *
   * @param array $node_access_grants
   *   An array of grants, as returned by node_access_grants().
   *
   * @return \Drupal\Core\Database\Query\Condition
   *   A condition object to be passed to $query->condition().
   *
   * @see node_access_grants()
   */
  protected static function buildGrantsQueryCondition(array $node_access_grants) {
    $grants = new Condition("OR");
    foreach ($node_access_grants as $realm => $gids) {
      if (!empty($gids)) {
        $and = new Condition('AND');
        $grants
          ->condition($and
          ->condition('gid', $gids, 'IN')
          ->condition('realm', $realm));
      }
    }
    return $grants;
  }

}

Classes

Name	Description
NodeGrantDatabaseStorage	Defines a storage handler class that handles the node grants system.