materio-base-d7/sites/all/modules/contrib/taxonomy/synonyms/synonyms_provider_property/synonyms_provider_property.module

<?php

/**
 * @file
 * Provides synonyms from entity properties.
 */

/**
 * Implements hook_synonyms_behavior_implementation_info().
 */
function synonyms_provider_property_synonyms_behavior_implementation_info($entity_type, $bundle, $behavior) {
  $providers = array();

  switch ($behavior) {
    case 'select':
    case 'autocomplete':
    case 'search':
      $entity_info = entity_get_info($entity_type);
      $class = $behavior == 'search' ? 'SearchPropertySynonymsBehavior' : 'PropertySynonymsBehavior';

      if ($entity_info['base table'] && isset($entity_info['entity keys']['id'])) {
        $entity_keys = array_filter($entity_info['entity keys']);
        $properties = entity_get_property_info($entity_type);
        $properties = $properties['properties'];

        // Label is the label of an entity, therefore it may not be a synonym.
        if (isset($entity_keys['label'])) {
          unset($properties[$entity_keys['label']]);
          unset($entity_keys['label']);
        }

        // Get all defined entity keys. We prefer them from entity keys rather
        // than from entity properties, because in the former case we know what
        // those keys represent (entity ID, bundle, etc), so we can give a bit
        // more unified UI by maintaining the same labels for the same entity
        // keys among different entity types.
        foreach ($entity_keys as $entity_key => $column) {
          if (in_array($column, $entity_info['schema_fields_sql']['base table'])) {
            $providers[] = array(
              'provider' => synonyms_provider_property_provider_name($column),
              'label' => $entity_key,
              'class' => $class,
            );

            unset($properties[$column]);
          }
        }

        foreach ($properties as $property => $property_info) {
          if (isset($property_info['schema field']) && $property_info['schema field']) {
            $providers[] = array(
              'provider' => synonyms_provider_property_provider_name($property_info['schema field']),
              'label' => $property_info['label'],
              'class' => $class,
            );
          }
        }
      }
      break;
  }

  return $providers;
}

/**
 * Construct synonyms provider name out of underlying property.
 *
 * This function is inverse of synonyms_provider_property_name().
 *
 * @param string $property
 *   Entity property name whose provider name should be constructed
 *
 * @return string
 *   Provider name that corresponds to the $property
 *
 * @see synonyms_provider_property_name()
 */
function synonyms_provider_property_provider_name($property) {
  return 'synonyms_provider_property_' . $property;
}

/**
 * Reconstruct entity property name from the name of its provider.
 *
 * This function is inverse of synonyms_provider_property_provider_name().
 *
 * @param string $provider
 *   Name of the provider whose underlying entity property should be
 *   reconstructed
 *
 * @return string
 *   Entity property name that corresponds to the $provider
 *
 * @see synonyms_provider_property_provider_name()
 */
function synonyms_provider_property_name($provider) {
  return drupal_substr($provider, drupal_strlen('synonyms_provider_property_'));
}