Club Drupal

<?php

/**

 * @file

 * Contains FeedsProcessor and related classes.

 */

// Update mode for existing items.

define('FEEDS_SKIP_EXISTING', 0);

define('FEEDS_REPLACE_EXISTING', 1);

define('FEEDS_UPDATE_EXISTING', 2);

// Options for handling content in Drupal but not in source data.

define('FEEDS_SKIP_NON_EXISTENT', 'skip');

define('FEEDS_DELETE_NON_EXISTENT', 'delete');

// Default limit for creating items on a page load, not respected by all

// processors.

define('FEEDS_PROCESS_LIMIT', 50);

/**

 * Thrown if a validation fails.

 */

class FeedsValidationException extends Exception {}

/**

 * Thrown if a an access check fails.

 */

class FeedsAccessException extends Exception {}

/**

 * Abstract class, defines interface for processors.

 */

abstract class FeedsProcessor extends FeedsPlugin {

  /**

   * Implements FeedsPlugin::pluginType().

   */

  public function pluginType() {

    return 'processor';

  }

  /**

   * @defgroup entity_api_wrapper Entity API wrapper.

   */

  /**

   * Entity type this processor operates on.

   */

  public abstract function entityType();

  /**

   * Bundle type this processor operates on.

   *

   * Defaults to the entity type for entities that do not define bundles.

   *

   * @return string|NULL

   *   The bundle type this processor operates on, or NULL if it is undefined.

   */

  public function bundle() {

    return $this->config['bundle'];

  }

  /**

   * Provides a list of bundle options for use in select lists.

   *

   * @return array

   *   A keyed array of bundle => label.

   */

  public function bundleOptions() {

    $options = array();

    foreach (field_info_bundles($this->entityType()) as $bundle => $info) {

      if (!empty($info['label'])) {

        $options[$bundle] = $info['label'];

      }

      else {

        $options[$bundle] = $bundle;

      }

    }

    return $options;

  }

  /**

   * Create a new entity.

   *

   * @param $source

   *   The feeds source that spawns this entity.

   *

   * @return

   *   A new entity object.

   */

  protected abstract function newEntity(FeedsSource $source);

  /**

   * Load an existing entity.

   *

   * @param $source

   *   The feeds source that spawns this entity.

   * @param $entity_id

   *   The unique id of the entity that should be loaded.

   *

   * @return

   *   A new entity object.

   *

   * @todo We should be able to batch load these, if we found all of the

   *   existing ids first.

   */

  protected function entityLoad(FeedsSource $source, $entity_id) {

    if ($this->config['update_existing'] == FEEDS_UPDATE_EXISTING) {

      $entities = entity_load($this->entityType(), array($entity_id));

      return reset($entities);

    }

    $info = $this->entityInfo();

    $args = array(':entity_id' => $entity_id);

    $table = db_escape_table($info['base table']);

    $key = db_escape_field($info['entity keys']['id']);

    return db_query("SELECT * FROM {" . $table . "} WHERE $key = :entity_id", $args)->fetchObject();

  }

  /**

   * Validate an entity.

   *

   * @throws FeedsValidationException $e

   *   If validation fails.

   */

  protected function entityValidate($entity) {}

  /**

   * Access check for saving an enity.

   *

   * @param $entity

   *   Entity to be saved.

   *

   * @throws FeedsAccessException $e

   *   If the access check fails.

   */

  protected function entitySaveAccess($entity) {}

  /**

   * Save an entity.

   *

   * @param $entity

   *   Entity to be saved.

   */

  protected abstract function entitySave($entity);

  /**

   * Delete a series of entities.

   *

   * @param $entity_ids

   *   Array of unique identity ids to be deleted.

   */

  protected abstract function entityDeleteMultiple($entity_ids);

  /**

   * Wrap entity_get_info() into a method so that extending classes can override

   * it and more entity information. Allowed additional keys:

   *

   * 'label plural' ... the plural label of an entity type.

   */

  protected function entityInfo() {

    return entity_get_info($this->entityType());

  }

  /**

   * @}

   */

  /**

   * Process the result of the parsing stage.

   *

   * @param FeedsSource $source

   *   Source information about this import.

   * @param FeedsParserResult $parser_result

   *   The result of the parsing stage.

   */

  public function process(FeedsSource $source, FeedsParserResult $parser_result) {

    $state = $source->state(FEEDS_PROCESS);

    if (!isset($state->removeList) && $parser_result->items) {

      $this->initEntitiesToBeRemoved($source, $state);

    }

    while ($item = $parser_result->shiftItem()) {

      // Check if this item already exists.

      $entity_id = $this->existingEntityId($source, $parser_result);

      // If it's included in the feed, it must not be removed on clean.

      if ($entity_id) {

        unset($state->removeList[$entity_id]);

      }

      $skip_existing = $this->config['update_existing'] == FEEDS_SKIP_EXISTING;

      module_invoke_all('feeds_before_update', $source, $item, $entity_id);

      // If it exists, and we are not updating, pass onto the next item.

      if ($entity_id && $skip_existing) {

        continue;

      }

      try {

        $hash = $this->hash($item);

        $changed = ($hash !== $this->getHash($entity_id));

        $force_update = $this->config['skip_hash_check'];

        // Do not proceed if the item exists, has not changed, and we're not

        // forcing the update.

        if ($entity_id && !$changed && !$force_update) {

          continue;

        }

        // Load an existing entity.

        if ($entity_id) {

          $entity = $this->entityLoad($source, $entity_id);

          // The feeds_item table is always updated with the info for the most

          // recently processed entity. The only carryover is the entity_id.

          $this->newItemInfo($entity, $source->feed_nid, $hash);

          $entity->feeds_item->entity_id = $entity_id;

          $entity->feeds_item->is_new = FALSE;

        }

        // Build a new entity.

        else {

          $entity = $this->newEntity($source);

          $this->newItemInfo($entity, $source->feed_nid, $hash);

        }

        // Set property and field values.

        $this->map($source, $parser_result, $entity);

        $this->entityValidate($entity);

        // Allow modules to alter the entity before saving.

        module_invoke_all('feeds_presave', $source, $entity, $item, $entity_id);

        if (module_exists('rules')) {

          rules_invoke_event('feeds_import_'. $source->importer()->id, $entity);

        }

        // Enable modules to skip saving at all.

        if (!empty($entity->feeds_item->skip)) {

          continue;

        }

        // This will throw an exception on failure.

        $this->entitySaveAccess($entity);

        $this->entitySave($entity);

        // Allow modules to perform operations using the saved entity data.

        // $entity contains the updated entity after saving.

        module_invoke_all('feeds_after_save', $source, $entity, $item, $entity_id);

        // Track progress.

        if (empty($entity_id)) {

          $state->created++;

        }

        else {

          $state->updated++;

        }

      }

      // Something bad happened, log it.

      catch (Exception $e) {

        $state->failed++;

        drupal_set_message($e->getMessage(), 'warning');

        list($message, $arguments) = $this->createLogEntry($e, $entity, $item);

        $source->log('import', $message, $arguments, WATCHDOG_ERROR);

      }

    }

    // Set messages if we're done.

    if ($source->progressImporting() != FEEDS_BATCH_COMPLETE) {

      return;

    }

    // Remove not included items if needed.

    // It depends on the implementation of the clean() method what will happen

    // to items that were no longer in the source.

    $this->clean($state);

    $info = $this->entityInfo();

    $tokens = array(

      '@entity' => strtolower($info['label']),

      '@entities' => strtolower($info['label plural']),

    );

    $messages = array();

    if ($state->created) {

      $messages[] = array(

       'message' => format_plural(

          $state->created,

          'Created @number @entity.',

          'Created @number @entities.',

          array('@number' => $state->created) + $tokens

        ),

      );

    }

    if ($state->updated) {

      $messages[] = array(

       'message' => format_plural(

          $state->updated,

          'Updated @number @entity.',

          'Updated @number @entities.',

          array('@number' => $state->updated) + $tokens

        ),

      );

    }

    if ($state->unpublished) {

      $messages[] = array(

        'message' => format_plural(

            $state->unpublished,

            'Unpublished @number @entity.',

            'Unpublished @number @entities.',

            array('@number' => $state->unpublished) + $tokens

        ),

      );

    }

    if ($state->blocked) {

      $messages[] = array(

        'message' => format_plural(

          $state->blocked,

          'Blocked @number @entity.',

          'Blocked @number @entities.',

          array('@number' => $state->blocked) + $tokens

        ),

      );

    }

    if ($state->deleted) {

      $messages[] = array(

       'message' => format_plural(

          $state->deleted,

          'Removed @number @entity.',

          'Removed @number @entities.',

          array('@number' => $state->deleted) + $tokens

        ),

      );

    }

    if ($state->failed) {

      $messages[] = array(

       'message' => format_plural(

          $state->failed,

          'Failed importing @number @entity.',

          'Failed importing @number @entities.',

          array('@number' => $state->failed) + $tokens

        ),

        'level' => WATCHDOG_ERROR,

      );

    }

    if (empty($messages)) {

      $messages[] = array(

        'message' => t('There are no new @entities.', array('@entities' => strtolower($info['label plural']))),

      );

    }

    foreach ($messages as $message) {

      drupal_set_message($message['message']);

      $source->log('import', $message['message'], array(), isset($message['level']) ? $message['level'] : WATCHDOG_INFO);

    }

  }

  /**

   * Initialize the array of entities to remove with all existing entities

   * previously imported from the source.

   *

   * @param FeedsSource $source

   *   Source information about this import.

   * @param FeedsState $state

   *   The FeedsState object for the given stage.

   */

  protected function initEntitiesToBeRemoved(FeedsSource $source, FeedsState $state) {

    $state->removeList = array();

    // We fill it only if needed.

    if (!isset($this->config['update_non_existent']) || $this->config['update_non_existent'] == FEEDS_SKIP_NON_EXISTENT) {

      return;

    }

    // Build base select statement.

    $info = $this->entityInfo();

    $id_key = db_escape_field($info['entity keys']['id']);

    $select = db_select($info['base table'], 'e');

    $select->addField('e', $info['entity keys']['id'], 'entity_id');

    $select->join(

      'feeds_item',

      'fi',

      'e.' . $id_key . ' = fi.entity_id AND fi.entity_type = :entity_type', array(

        ':entity_type' => $this->entityType(),

    ));

    $select->condition('fi.id', $this->id);

    $select->condition('fi.feed_nid', $source->feed_nid);

    // No need to remove item again if same method of removal was already used.

    $select->condition('fi.hash', $this->config['update_non_existent'], '<>');

    $entities = $select->execute();

    // If not found on process, existing entities will be deleted.

    foreach ($entities as $entity) {

      // Obviously, items which are still included in the source feed will be

      // removed from this array when processed.

      $state->removeList[$entity->entity_id] = $entity->entity_id;

    }

  }

  /**

   * Deletes entities which were not found during processing.

   *

   * @todo batch delete?

   *

   * @param FeedsState $state

   *   The FeedsState object for the given stage.

   */

  protected function clean(FeedsState $state) {

    // We clean only if needed.

    if (!isset($this->config['update_non_existent']) || $this->config['update_non_existent'] == FEEDS_SKIP_NON_EXISTENT) {

      return;

    }

    $total = count($state->removeList);

    if ($total) {

      $this->entityDeleteMultiple($state->removeList);

      $state->deleted += $total;

    }

  }

  /**

   * Remove all stored results or stored results up to a certain time for a

   * source.

   *

   * @param FeedsSource $source

   *   Source information for this expiry. Implementers should only delete items

   *   pertaining to this source. The preferred way of determining whether an

   *   item pertains to a certain souce is by using $source->feed_nid. It is the

   *   processor's responsibility to store the feed_nid of an imported item in

   *   the processing stage.

   */

  public function clear(FeedsSource $source) {

    $state = $source->state(FEEDS_PROCESS_CLEAR);

    // Build base select statement.

    $info = $this->entityInfo();

    $select = db_select($info['base table'], 'e');

    $select->addField('e', $info['entity keys']['id'], 'entity_id');

    $select->join(

      'feeds_item',

      'fi',

      "e.{$info['entity keys']['id']} = fi.entity_id AND fi.entity_type = '{$this->entityType()}'");

    $select->condition('fi.id', $this->id);

    $select->condition('fi.feed_nid', $source->feed_nid);

    // If there is no total, query it.

    if (!$state->total) {

      $state->total = $select->countQuery()

        ->execute()

        ->fetchField();

    }

    // Delete a batch of entities.

    $entities = $select->range(0, $this->getLimit())->execute();

    $entity_ids = array();

    foreach ($entities as $entity) {

      $entity_ids[$entity->entity_id] = $entity->entity_id;

    }

    $this->entityDeleteMultiple($entity_ids);

    // Report progress, take into account that we may not have deleted as

    // many items as we have counted at first.

    if (count($entity_ids)) {

      $state->deleted += count($entity_ids);

      $state->progress($state->total, $state->deleted);

    }

    else {

      $state->progress($state->total, $state->total);

    }

    // Report results when done.

    if ($source->progressClearing() == FEEDS_BATCH_COMPLETE) {

      if ($state->deleted) {

        $message = format_plural(

          $state->deleted,

          'Deleted @number @entity',

          'Deleted @number @entities',

          array(

            '@number' => $state->deleted,

            '@entity' => strtolower($info['label']),

            '@entities' => strtolower($info['label plural']),

          )

        );

        $source->log('clear', $message, array(), WATCHDOG_INFO);

        drupal_set_message($message);

      }

      else {

        drupal_set_message(t('There are no @entities to be deleted.', array('@entities' => $info['label plural'])));

      }

    }

  }

  /*

   * Report number of items that can be processed per call.

   *

   * 0 means 'unlimited'.

   *

   * If a number other than 0 is given, Feeds parsers that support batching

   * will only deliver this limit to the processor.

   *

   * @see FeedsSource::getLimit()

   * @see FeedsCSVParser::parse()

   */

  public function getLimit() {

    return variable_get('feeds_process_limit', FEEDS_PROCESS_LIMIT);

  }

  /**

   * Deletes feed items older than REQUEST_TIME - $time.

   *

   * Do not invoke expire on a processor directly, but use

   * FeedsSource::expire() instead.

   *

   * @param FeedsSource $source

   *   The source to expire entities for.

   *

   * @param $time

   *   (optional) All items produced by this configuration that are older than

   *   REQUEST_TIME - $time should be deleted. If NULL, processor should use

   *   internal configuration. Defaults to NULL.

   *

   * @return float

   *   FEEDS_BATCH_COMPLETE if all items have been processed, a float between 0

   *   and 0.99* indicating progress otherwise.

   *

   * @see FeedsSource::expire()

   */

  public function expire(FeedsSource $source, $time = NULL) {

    $state = $source->state(FEEDS_PROCESS_EXPIRE);

    if ($time === NULL) {

      $time = $this->expiryTime();

    }

    if ($time == FEEDS_EXPIRE_NEVER) {

      return;

    }

    $select = $this->expiryQuery($source, $time);

    // If there is no total, query it.

    if (!$state->total) {

      $state->total = $select->countQuery()->execute()->fetchField();

    }

    // Delete a batch of entities.

    $entity_ids = $select->range(0, $this->getLimit())->execute()->fetchCol();

    if ($entity_ids) {

      $this->entityDeleteMultiple($entity_ids);

      $state->deleted += count($entity_ids);

      $state->progress($state->total, $state->deleted);

    }

    else {

      $state->progress($state->total, $state->total);

    }

  }

  /**

   * Returns a database query used to select entities to expire.

   *

   * Processor classes should override this method to set the age portion of the

   * query.

   *

   * @param FeedsSource $source

   *   The feed source.

   * @param int $time

   *   Delete entities older than this.

   *

   * @return SelectQuery

   *   A select query to execute.

   *

   * @see FeedsNodeProcessor::expiryQuery()

   */

  protected function expiryQuery(FeedsSource $source, $time) {

    // Build base select statement.

    $info = $this->entityInfo();

    $id_key = db_escape_field($info['entity keys']['id']);

    $select = db_select($info['base table'], 'e');

    $select->addField('e', $info['entity keys']['id'], 'entity_id');

    $select->join(

      'feeds_item',

      'fi',

      "e.$id_key = fi.entity_id AND fi.entity_type = :entity_type", array(

        ':entity_type' => $this->entityType(),

    ));

    $select->condition('fi.id', $this->id);

    $select->condition('fi.feed_nid', $source->feed_nid);

    return $select;

  }

  /**

   * Counts the number of items imported by this processor.

   */

  public function itemCount(FeedsSource $source) {

    return db_query("SELECT count(*) FROM {feeds_item} WHERE id = :id AND entity_type = :entity_type AND feed_nid = :feed_nid", array(':id' => $this->id, ':entity_type' => $this->entityType(), ':feed_nid' => $source->feed_nid))->fetchField();

  }

  /**

   * Returns a statically cached version of the target mappings.

   *

   * @return array

   *   The targets for this importer.

   */

  protected function getCachedTargets() {

    $targets = &drupal_static('FeedsProcessor::getCachedTargets', array());

    if (!isset($targets[$this->id])) {

      $targets[$this->id] = $this->getMappingTargets();

    }

    return $targets[$this->id];

  }

  /**

   * Returns a statically cached version of the source mappings.

   *

   * @return array

   *   The sources for this importer.

   */

  protected function getCachedSources() {

    $sources = &drupal_static('FeedsProcessor::getCachedSources', array());

    if (!isset($sources[$this->id])) {

      $sources[$this->id] = feeds_importer($this->id)->parser->getMappingSources();

      if (is_array($sources[$this->id])) {

        foreach ($sources[$this->id] as $source_key => $source) {

          if (empty($source['callback']) || !is_callable($source['callback'])) {

            unset($sources[$this->id][$source_key]['callback']);

          }

        }

      }

    }

    return $sources[$this->id];

  }

  /**

   * Execute mapping on an item.

   *

   * This method encapsulates the central mapping functionality. When an item is

   * processed, it is passed through map() where the properties of $source_item

   * are mapped onto $target_item following the processor's mapping

   * configuration.

   *

   * For each mapping FeedsParser::getSourceElement() is executed to retrieve

   * the source element, then FeedsProcessor::setTargetElement() is invoked

   * to populate the target item properly. Alternatively a

   * hook_x_targets_alter() may have specified a callback for a mapping target

   * in which case the callback is asked to populate the target item instead of

   * FeedsProcessor::setTargetElement().

   *

   * @ingroup mappingapi

   *

   * @see hook_feeds_parser_sources_alter()

   * @see hook_feeds_processor_targets()

   * @see hook_feeds_processor_targets_alter()

   */

  protected function map(FeedsSource $source, FeedsParserResult $result, $target_item = NULL) {

    $targets = $this->getCachedTargets();

    if (empty($target_item)) {

      $target_item = array();

    }

    // Many mappers add to existing fields rather than replacing them. Hence we

    // need to clear target elements of each item before mapping in case we are

    // mapping on a prepopulated item such as an existing node.

    foreach ($this->config['mappings'] as $mapping) {

      if (isset($targets[$mapping['target']]['real_target'])) {

        $target_item->{$targets[$mapping['target']]['real_target']} = NULL;

      }

      else {

        $target_item->{$mapping['target']} = NULL;

      }

    }

    // This is where the actual mapping happens: For every mapping we invoke

    // the parser's getSourceElement() method to retrieve the value of the

    // source element and pass it to the processor's setTargetElement() to stick

    // it on the right place of the target item.

    foreach ($this->config['mappings'] as $mapping) {

      $value = $this->getSourceValue($source, $result, $mapping['source']);

      $this->mapToTarget($source, $mapping['target'], $target_item, $value, $mapping);

    }

    return $target_item;

  }

  /**

   * Returns the values from the parser, or callback.

   *

   * @param FeedsSource $source

   *   The feed source.

   * @param FeedsParserResult $result

   *   The parser result.

   * @param string $source_key

   *   The current key being processed.

   *

   * @return mixed

   *   A value, or a list of values.

   */

  protected function getSourceValue(FeedsSource $source, FeedsParserResult $result, $source_key) {

    $sources = $this->getCachedSources();

    if (isset($sources[$source_key]['callback'])) {

      return call_user_func($sources[$source_key]['callback'], $source, $result, $source_key);

    }

    return feeds_importer($this->id)->parser->getSourceElement($source, $result, $source_key);

  }

  /**

   * Maps values onto the target item.

   *

   * @param FeedsSource $source

   *   The feed source.

   * @param mixed &$target_item

   *   The target item to apply values into.

   * @param mixed $value

   *   A value, or a list of values.

   * @param array $mapping

   *   The mapping configuration.

   */

  protected function mapToTarget(FeedsSource $source, $target, &$target_item, $value, array $mapping) {

    $targets = $this->getCachedTargets();

    if (isset($targets[$target]['preprocess_callbacks'])) {

      foreach ($targets[$target]['preprocess_callbacks'] as $callback) {

        call_user_func_array($callback, array($source, $target_item, $target, &$mapping));

      }

    }

    // Map the source element's value to the target.

    // If the mapping specifies a callback method, use the callback instead of

    // setTargetElement().

    if (isset($targets[$target]['callback'])) {

      // All target callbacks expect an array.

      if (!is_array($value)) {

        $value = array($value);

      }

      call_user_func($targets[$target]['callback'], $source, $target_item, $target, $value, $mapping);

    }

    else {

      $this->setTargetElement($source, $target_item, $target, $value, $mapping);

    }

  }

  /**

   * Per default, don't support expiry. If processor supports expiry of imported

   * items, return the time after which items should be removed.

   */

  public function expiryTime() {

    return FEEDS_EXPIRE_NEVER;

  }

  /**

   * Declare default configuration.

   */

  public function configDefaults() {

    $info = $this->entityInfo();

    $bundle = NULL;

    if (empty($info['entity keys']['bundle'])) {

      $bundle = $this->entityType();

    }

    return array(

      'mappings' => array(),

      'update_existing' => FEEDS_SKIP_EXISTING,

      'update_non_existent' => FEEDS_SKIP_NON_EXISTENT,

      'input_format' => NULL,

      'skip_hash_check' => FALSE,

      'bundle' => $bundle,

    );

  }

  /**

   * Overrides parent::configForm().

   */

  public function configForm(&$form_state) {

    $info = $this->entityInfo();

    $form = array();

    if (!empty($info['entity keys']['bundle'])) {

      $form['bundle'] = array(

        '#type' => 'select',

        '#options' => $this->bundleOptions(),

        '#title' => !empty($info['bundle name']) ? $info['bundle name'] : t('Bundle'),

        '#required' => TRUE,

        '#default_value' => $this->bundle(),

      );

    }

    else {

      $form['bundle'] = array(

        '#type' => 'value',

        '#value' => $this->entityType(),

      );

    }

    $tokens = array('@entities' => strtolower($info['label plural']));

    $form['update_existing'] = array(

      '#type' => 'radios',

      '#title' => t('Update existing @entities', $tokens),

      '#description' =>

        t('Existing @entities will be determined using mappings that are a "unique target".', $tokens),

      '#options' => array(

        FEEDS_SKIP_EXISTING => t('Do not update existing @entities', $tokens),

        FEEDS_REPLACE_EXISTING => t('Replace existing @entities', $tokens),

        FEEDS_UPDATE_EXISTING => t('Update existing @entities', $tokens),

      ),

      '#default_value' => $this->config['update_existing'],

    );

    global $user;

    $formats = filter_formats($user);

    foreach ($formats as $format) {

      $format_options[$format->format] = $format->name;

    }

    $form['skip_hash_check'] = array(

      '#type' => 'checkbox',

      '#title' => t('Skip hash check'),

      '#description' => t('Force update of items even if item source data did not change.'),

      '#default_value' => $this->config['skip_hash_check'],

    );

    $form['input_format'] = array(

      '#type' => 'select',

      '#title' => t('Text format'),

      '#description' => t('Select the default input format for the text fields of the nodes to be created.'),

      '#options' => $format_options,

      '#default_value' => isset($this->config['input_format']) ? $this->config['input_format'] : 'plain_text',

      '#required' => TRUE,

    );

    $form['update_non_existent'] = array(

      '#type' => 'radios',

      '#title' => t('Action to take when previously imported @entities are missing in the feed', $tokens),

      '#description' => t('Select how @entities previously imported and now missing in the feed should be updated.', $tokens),

      '#options' => array(

        FEEDS_SKIP_NON_EXISTENT => t('Skip non-existent @entities', $tokens),

        FEEDS_DELETE_NON_EXISTENT => t('Delete non-existent @entities', $tokens),

      ),

      '#default_value' => $this->config['update_non_existent'],

    );

    return $form;

  }

  /**

   * Get mappings.

   */

  public function getMappings() {

    return isset($this->config['mappings']) ? $this->config['mappings'] : array();

  }

  /**

   * Declare possible mapping targets that this processor exposes.

   *

   * @ingroup mappingapi

   *

   * @return

   *   An array of mapping targets. Keys are paths to targets

   *   separated by ->, values are TRUE if target can be unique,

   *   FALSE otherwise.

   */

  public function getMappingTargets() {

    // The bundle has not been selected.

    if (!$this->bundle()) {

      $info = $this->entityInfo();

      $bundle_name = !empty($info['bundle name']) ? drupal_strtolower($info['bundle name']) : t('bundle');

      $plugin_key = feeds_importer($this->id)->config['processor']['plugin_key'];

      $url = url('admin/structure/feeds/' . $this->id . '/settings/' . $plugin_key);

      drupal_set_message(t('Please <a href="@url">select a @bundle_name</a>.', array('@url' => $url, '@bundle_name' => $bundle_name)), 'warning', FALSE);

    }

    return array(

      'url' => array(

        'name' => t('URL'),

        'description' => t('The external URL of the item. E. g. the feed item URL in the case of a syndication feed. May be unique.'),

        'optional_unique' => TRUE,

      ),

      'guid' => array(

        'name' => t('GUID'),

        'description' => t('The globally unique identifier of the item. E. g. the feed item GUID in the case of a syndication feed. May be unique.'),

        'optional_unique' => TRUE,

      ),

    );

  }

  /**

   * Allows other modules to expose targets.

   *

   * @param array &$targets

   *   The existing target array.

   */

  protected function getHookTargets(array &$targets) {

    self::loadMappers();

    $entity_type = $this->entityType();

    $bundle = $this->bundle();

    $targets += module_invoke_all('feeds_processor_targets', $entity_type, $bundle);

    drupal_alter('feeds_processor_targets', $targets, $entity_type, $bundle);

  }

  /**

   * Set a concrete target element. Invoked from FeedsProcessor::map().

   *

   * @ingroup mappingapi

   */

  public function setTargetElement(FeedsSource $source, $target_item, $target_element, $value) {

    switch ($target_element) {

      case 'url':

      case 'guid':

        $target_item->feeds_item->$target_element = $value;

        break;

      default:

        $target_item->$target_element = $value;

        break;

    }

  }

  /**

   * Retrieve the target entity's existing id if available. Otherwise return 0.

   *

   * @ingroup mappingapi

   *

   * @param FeedsSource $source

   *   The source information about this import.

   * @param FeedsParserResult $result

   *   A FeedsParserResult object.

   *

   * @return int

   *   The serial id of an entity if found, 0 otherwise.

   */

  protected function existingEntityId(FeedsSource $source, FeedsParserResult $result) {

    $targets = $this->getCachedTargets();

    $entity_id = 0;

    // Iterate through all unique targets and test whether they already exist in

    // the database.

    foreach ($this->uniqueTargets($source, $result) as $target => $value) {

      if ($target === 'guid' || $target === 'url') {

        $entity_id = db_select('feeds_item')

          ->fields('feeds_item', array('entity_id'))

          ->condition('feed_nid', $source->feed_nid)

          ->condition('entity_type', $this->entityType())

          ->condition('id', $source->id)

          ->condition($target, $value)

          ->execute()

          ->fetchField();

      }

      if (!$entity_id && !empty($targets[$target]['unique_callbacks'])) {

        if (!is_array($value)) {

          $value = array($value);

        }

        foreach ($targets[$target]['unique_callbacks'] as $callback) {

          if ($entity_id = call_user_func($callback, $source, $this->entityType(), $this->bundle(), $target, $value)) {

            // Stop at the first unique ID returned by a callback.

            break;

          }

        }

      }

      // Return with the content id found.

      if ($entity_id) {

        return $entity_id;

      }

    }

    return $entity_id;

  }

  /**

   * Utility function that iterates over a target array and retrieves all

   * sources that are unique.

   *

   * @param $batch

   *   A FeedsImportBatch.

   *

   * @return

   *   An array where the keys are target field names and the values are the

   *   elements from the source item mapped to these targets.

   */

  protected function uniqueTargets(FeedsSource $source, FeedsParserResult $result) {

    $parser = feeds_importer($this->id)->parser;

    $targets = array();

    foreach ($this->config['mappings'] as $mapping) {

      if (!empty($mapping['unique'])) {

        // Invoke the parser's getSourceElement to retrieve the value for this

        // mapping's source.

        $targets[$mapping['target']] = $parser->getSourceElement($source, $result, $mapping['source']);

      }

    }

    return $targets;

  }

  /**

   * Adds Feeds specific information on $entity->feeds_item.

   *

   * @param $entity

   *   The entity object to be populated with new item info.

   * @param $feed_nid

   *   The feed nid of the source that produces this entity.

   * @param $hash

   *   The fingerprint of the source item.

   */

  protected function newItemInfo($entity, $feed_nid, $hash = '') {

    $entity->feeds_item = new stdClass();

    $entity->feeds_item->is_new = TRUE;

    $entity->feeds_item->entity_id = 0;

    $entity->feeds_item->entity_type = $this->entityType();

    $entity->feeds_item->id = $this->id;

    $entity->feeds_item->feed_nid = $feed_nid;

    $entity->feeds_item->imported = REQUEST_TIME;

    $entity->feeds_item->hash = $hash;

    $entity->feeds_item->url = '';

    $entity->feeds_item->guid = '';

  }

  /**

   * Loads existing entity information and places it on $entity->feeds_item.

   *

   * @param $entity

   *   The entity object to load item info for. Id key must be present.

   *

   * @return

   *   TRUE if item info could be loaded, false if not.

   */

  protected function loadItemInfo($entity) {

    $entity_info = entity_get_info($this->entityType());

    $key = $entity_info['entity keys']['id'];

    if ($item_info = feeds_item_info_load($this->entityType(), $entity->$key)) {

      $entity->feeds_item = $item_info;

      return TRUE;

    }

    return FALSE;

  }

  /**

   * Create MD5 hash of item and mappings array.

   *

   * Include mappings as a change in mappings may have an affect on the item

   * produced.

   *

   * @return Always returns a hash, even with empty, NULL, FALSE:

   *  Empty arrays return 40cd750bba9870f18aada2478b24840a

   *  Empty/NULL/FALSE strings return d41d8cd98f00b204e9800998ecf8427e

   */

  protected function hash($item) {

    return hash('md5', serialize($item) . serialize($this->config['mappings']));

  }

  /**

   * Retrieves the MD5 hash of $entity_id from the database.

   *

   * @return string

   *   Empty string if no item is found, hash otherwise.

   */

  protected function getHash($entity_id) {

    if ($hash = db_query("SELECT hash FROM {feeds_item} WHERE entity_type = :type AND entity_id = :id", array(':type' => $this->entityType(), ':id' => $entity_id))->fetchField()) {

      // Return with the hash.

      return $hash;

    }

    return '';

  }

  /**

   * DEPRECATED: Creates a log message for exceptions during import.

   *

   * Don't use this method as it concatenates user variables into the log

   * message, which will pollute the locales_source table when the log message

   * is translated. Use ::createLogEntry instead.

   *

   * @param Exception $e

   *   The exception that was throwned during processing the item.

   * @param $entity

   *   The entity object.

   * @param $item

   *   The parser result for this entity.

   *

   * @return string

   *   The message to log.

   *

   * @deprecated

   *   Use ::createLogEntry instead.

   */

  protected function createLogMessage(Exception $e, $entity, $item) {

    $message = $e->getMessage();

    $message .= '<h3>Original item</h3>';

    // $this->exportObjectVars() already runs check_plain() for us, so we can

    // concatenate here as is.

    $message .= '<pre>' . $this->exportObjectVars($item) . '</pre>';

    $message .= '<h3>Entity</h3>';

    $message .= '<pre>' . $this->exportObjectVars($entity) . '</pre>';

    return $message;

  }

  /**

   * Creates a log entry for when an exception occured during import.

   *

   * @param Exception $e

   *   The exception that was throwned during processing the item.

   * @param object $entity

   *   The entity object.

   * @param array $item

   *   The parser result for this entity.

   *

   * @return array

   *   The message and arguments to log.

   */

  protected function createLogEntry(Exception $e, $entity, $item) {

    $message = '@exception';

    $message .= '<h3>Original item</h3>';

    $message .= '<pre>!item</pre>';

    $message .= '<h3>Entity</h3>';

    $message .= '<pre>!entity</pre>';

    $arguments = array(

      '@exception' => $e->getMessage(),

      // $this->exportObjectVars() already runs check_plain() for us, so we can

      // use the "!" placeholder.

      '!item' => $this->exportObjectVars($item),

      '!entity' => $this->exportObjectVars($entity),

    );

    return array($message, $arguments);

  }

  /**

   * Returns a string representation of an object or array for log messages.

   *

   * @param object|array $object

   *   The object to convert.

   *

   * @return string

   *   The sanitized string representation of the object.

   */

  protected function exportObjectVars($object) {

    include_once DRUPAL_ROOT . '/includes/utility.inc';

    $out = is_array($object) ? $object : get_object_vars($object);

    $out = array_filter($out, 'is_scalar');

    foreach ($out as $key => $value) {

      if (is_string($value)) {

        $out[$key] = truncate_utf8($value, 100, FALSE, TRUE);

      }

    }

    if (is_array($object)) {

      return check_plain(drupal_var_export($out));

    }

    return check_plain(drupal_var_export((object) $out));

  }

  /**

   * Overrides FeedsPlugin::dependencies().

   */

  public function dependencies() {

    $dependencies = parent::dependencies();

    // Find out which module defined the entity type.

    $info = $this->entityInfo();

    if (isset($info['module'])) {

      $dependencies[$info['module']] = $info['module'];

    }

    return $dependencies;

  }

}

class FeedsProcessorBundleNotDefined extends Exception {}