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Diffstat (limited to 'engine/classes/ElggAttributeLoader.php')
| -rw-r--r-- | engine/classes/ElggAttributeLoader.php | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/engine/classes/ElggAttributeLoader.php b/engine/classes/ElggAttributeLoader.php new file mode 100644 index 000000000..ffc80b02d --- /dev/null +++ b/engine/classes/ElggAttributeLoader.php @@ -0,0 +1,248 @@ +<?php + +/** + * Loads ElggEntity attributes from DB or validates those passed in via constructor + * + * @access private + * + * @package Elgg.Core + * @subpackage DataModel + */ +class ElggAttributeLoader { + + /** + * @var array names of attributes in all entities + */ + protected static $primary_attr_names = array( + 'guid', + 'type', + 'subtype', + 'owner_guid', + 'container_guid', + 'site_guid', + 'access_id', + 'time_created', + 'time_updated', + 'last_action', + 'enabled', + ); + + /** + * @var array names of secondary attributes required for the entity + */ + protected $secondary_attr_names = array(); + + /** + * @var string entity type (not class) required for fetched primaries + */ + protected $required_type; + + /** + * @var array + */ + protected $initialized_attributes; + + /** + * @var string class of object being loaded + */ + protected $class; + + /** + * @var bool should access control be considered when fetching entity? + */ + public $requires_access_control = true; + + /** + * @var callable function used to load attributes from {prefix}entities table + */ + public $primary_loader = 'get_entity_as_row'; + + /** + * @var callable function used to load attributes from secondary table + */ + public $secondary_loader = ''; + + /** + * @var callable function used to load all necessary attributes + */ + public $full_loader = ''; + + /** + * Constructor + * + * @param string $class class of object being loaded + * @param string $required_type entity type this is being used to populate + * @param array $initialized_attrs attributes after initializeAttributes() has been run + * @throws InvalidArgumentException + */ + public function __construct($class, $required_type, array $initialized_attrs) { + if (!is_string($class)) { + throw new InvalidArgumentException('$class must be a class name.'); + } + $this->class = $class; + + if (!is_string($required_type)) { + throw new InvalidArgumentException('$requiredType must be a system entity type.'); + } + $this->required_type = $required_type; + + $this->initialized_attributes = $initialized_attrs; + unset($initialized_attrs['tables_split'], $initialized_attrs['tables_loaded']); + $all_attr_names = array_keys($initialized_attrs); + $this->secondary_attr_names = array_diff($all_attr_names, self::$primary_attr_names); + } + + /** + * Get primary attributes missing that are missing + * + * @param stdClass $row Database row + * @return array + */ + protected function isMissingPrimaries($row) { + return array_diff(self::$primary_attr_names, array_keys($row)) !== array(); + } + + /** + * Get secondary attributes that are missing + * + * @param stdClass $row Database row + * @return array + */ + protected function isMissingSecondaries($row) { + return array_diff($this->secondary_attr_names, array_keys($row)) !== array(); + } + + /** + * Check that the type is correct + * + * @param stdClass $row Database row + * @return void + * @throws InvalidClassException + */ + protected function checkType($row) { + if ($row['type'] !== $this->required_type) { + $msg = elgg_echo('InvalidClassException:NotValidElggStar', array($row['guid'], $this->class)); + throw new InvalidClassException($msg); + } + } + + /** + * Get all required attributes for the entity, validating any that are passed in. Returns empty array + * if can't be loaded (Check $failure_reason). + * + * This function splits loading between "primary" attributes (those in {prefix}entities table) and + * "secondary" attributes (e.g. those in {prefix}objects_entity), but can load all at once if a + * combined loader is available. + * + * @param mixed $row a row loaded from DB (array or stdClass) or a GUID + * @return array will be empty if failed to load all attributes (access control or entity doesn't exist) + * + * @throws InvalidArgumentException|LogicException|IncompleteEntityException + */ + public function getRequiredAttributes($row) { + if (!is_array($row) && !($row instanceof stdClass)) { + // assume row is the GUID + $row = array('guid' => $row); + } + $row = (array) $row; + if (empty($row['guid'])) { + throw new InvalidArgumentException('$row must be or contain a GUID'); + } + + // these must be present to support isFullyLoaded() + foreach (array('tables_split', 'tables_loaded') as $key) { + if (isset($this->initialized_attributes[$key])) { + $row[$key] = $this->initialized_attributes[$key]; + } + } + + $was_missing_primaries = $this->isMissingPrimaries($row); + $was_missing_secondaries = $this->isMissingSecondaries($row); + + // some types have a function to load all attributes at once, it should be faster + if (($was_missing_primaries || $was_missing_secondaries) && is_callable($this->full_loader)) { + $fetched = (array) call_user_func($this->full_loader, $row['guid']); + if (!$fetched) { + return array(); + } + $row = array_merge($row, $fetched); + $this->checkType($row); + } else { + if ($was_missing_primaries) { + if (!is_callable($this->primary_loader)) { + throw new LogicException('Primary attribute loader must be callable'); + } + if ($this->requires_access_control) { + $fetched = (array) call_user_func($this->primary_loader, $row['guid']); + } else { + $ignoring_access = elgg_set_ignore_access(); + $fetched = (array) call_user_func($this->primary_loader, $row['guid']); + elgg_set_ignore_access($ignoring_access); + } + if (!$fetched) { + return array(); + } + $row = array_merge($row, $fetched); + } + + // We must test type before trying to load the secondaries so that InvalidClassException + // gets thrown. Otherwise the secondary loader will fail and return false. + $this->checkType($row); + + if ($was_missing_secondaries) { + if (!is_callable($this->secondary_loader)) { + throw new LogicException('Secondary attribute loader must be callable'); + } + $fetched = (array) call_user_func($this->secondary_loader, $row['guid']); + if (!$fetched) { + if ($row['type'] === 'site') { + // A special case is needed for sites: When vanilla ElggEntities are created and + // saved, these are stored w/ type "site", but with no sites_entity row. These + // are probably only created in the unit tests. + // @todo Don't save vanilla ElggEntities with type "site" + + $row = $this->filterAddedColumns($row); + $row['guid'] = (int) $row['guid']; + return $row; + } + throw new IncompleteEntityException("Secondary loader failed to return row for {$row['guid']}"); + } + $row = array_merge($row, $fetched); + } + } + + $row = $this->filterAddedColumns($row); + + // Note: If there are still missing attributes, we're running on a 1.7 or earlier schema. We let + // this pass so the upgrades can run. + + // guid needs to be an int https://github.com/elgg/elgg/issues/4111 + $row['guid'] = (int) $row['guid']; + + return $row; + } + + /** + * Filter out keys returned by the query which should not appear in the entity's attributes + * + * @param array $row All columns from the query + * @return array Columns acceptable for the entity's attributes + */ + protected function filterAddedColumns($row) { + // make an array with keys as acceptable attribute names + $acceptable_attrs = self::$primary_attr_names; + array_splice($acceptable_attrs, count($acceptable_attrs), 0, $this->secondary_attr_names); + $acceptable_attrs = array_combine($acceptable_attrs, $acceptable_attrs); + + // @todo remove these when #4584 is in place + $acceptable_attrs['tables_split'] = true; + $acceptable_attrs['tables_loaded'] = true; + + foreach ($row as $key => $val) { + if (!isset($acceptable_attrs[$key])) { + unset($row[$key]); + } + } + return $row; + } +} |