gistfile1.txt

diff --git a/config/schema/search_api.index.schema.yml b/config/schema/search_api.index.schema.yml
index 96a0abb..7cbced6 100644
--- a/config/schema/search_api.index.schema.yml
+++ b/config/schema/search_api.index.schema.yml
@@ -34,6 +34,9 @@ search_api.index.*:
               boost:
                 type: float
                 label: 'Boost'
+              faceted:
+                type: boolean
+                label: 'Faceted'
         additional fields:
           type: sequence
           label: 'Included additional fields'
diff --git a/search_api.links.task.yml b/search_api.links.task.yml
index 8eb808c..8ea2898 100644
--- a/search_api.links.task.yml
+++ b/search_api.links.task.yml
@@ -25,3 +25,8 @@ entity.search_api_index.processors:
   base_route: entity.search_api_index.canonical
   title: 'Processors'
   weight: 20
+entity.search_api_index.facets:
+  route_name: entity.search_api_index.facets
+  base_route: entity.search_api_index.canonical
+  title: 'Facets'
+  weight: 20
diff --git a/search_api.routing.yml b/search_api.routing.yml
index 195fb28..9bea273 100644
--- a/search_api.routing.yml
+++ b/search_api.routing.yml
@@ -109,6 +109,13 @@ entity.search_api_index.fields:
   requirements:
     _entity_access: 'search_api_index.fields'
 
+entity.search_api_index.facets:
+  path: '/admin/config/search/search-api/index/{search_api_index}/facets'
+  defaults:
+    _entity_form: 'search_api_index.facets'
+  requirements:
+    _entity_access: 'search_api_index.facets'
+
 entity.search_api_index.processors:
   path: '/admin/config/search/search-api/index/{search_api_index}/processors'
   defaults:
diff --git a/search_api.theme.inc b/search_api.theme.inc
index 080aa02..5131fef 100644
--- a/search_api.theme.inc
+++ b/search_api.theme.inc
@@ -24,7 +24,7 @@ use Drupal\search_api\Utility;
  */
 function theme_search_api_admin_fields_table($variables) {
   $form = $variables['element'];
-  $header = array(t('Field'), t('Machine name'), t('Indexed'), t('Type'), t('Boost'));
+  $header = array(t('Field'), t('Machine name'), t('Indexed'), t('Type'), t('Boost'), t('Facet'));
 
   $rows = array();
   if (!empty($form['fields'])) {
@@ -303,7 +303,10 @@ function theme_search_api_index($variables) {
       $vars = array('@url' => Url::fromUri('https://drupal.org/node/2009804#server-index-status')->toString());
       // Build the server index status info.
       $label = t('Server index status');
-      $info = \Drupal::translation()->formatPlural($response->getResultCount(), 'There is 1 item indexed on the server for this index. (<a href="@url">More information</a>)', 'There are @count items indexed on the server for this index. (<a href="@url">More information</a>)', $vars);
+      $info = "";
+      if (!empty($response)) {
+        $info = \Drupal::translation()->formatPlural($response->getResultCount(), 'There is 1 item indexed on the server for this index. (<a href="@url">More information</a>)', 'There are @count items indexed on the server for this index. (<a href="@url">More information</a>)', $vars);
+      }
       $rows[] = Utility::deepCopy($row);
     }
 
diff --git a/src/Entity/Index.php b/src/Entity/Index.php
index 8a34290..7ce460b 100644
--- a/src/Entity/Index.php
+++ b/src/Entity/Index.php
@@ -41,6 +41,7 @@ use Drupal\views\Views;
  *       "edit" = "Drupal\search_api\Form\IndexForm",
  *       "fields" = "Drupal\search_api\Form\IndexFieldsForm",
  *       "processors" = "Drupal\search_api\Form\IndexProcessorsForm",
+ *       "facets" = "Drupal\search_api\Form\IndexFacetsForm",
  *       "delete" = "Drupal\search_api\Form\IndexDeleteConfirmForm",
  *       "disable" = "Drupal\search_api\Form\IndexDisableConfirmForm",
  *       "reindex" = "Drupal\search_api\Form\IndexReindexConfirmForm",
@@ -817,9 +818,14 @@ class Index extends ConfigEntityBase implements IndexInterface {
         $field->setIndexed(TRUE);
         if (isset($field_options[$key])) {
           $field->setType($field_options[$key]['type']);
+
           if (isset($field_options[$key]['boost'])) {
             $field->setBoost($field_options[$key]['boost']);
           }
+
+          if (isset($field_options[$key]['faceted'])) {
+            $field->setFaceted($field_options[$key]['faceted']);
+          }
         }
         $this->fields[1]['fields'][$key] = $field;
       }
diff --git a/src/Form/IndexFacetsForm.php b/src/Form/IndexFacetsForm.php
index efa30b5..bcc2cba 100644
--- a/src/Form/IndexFacetsForm.php
+++ b/src/Form/IndexFacetsForm.php
@@ -2,24 +2,20 @@
 
 /**
  * @file
- * Contains \Drupal\search_api\Form\IndexProcessorsForm.
+ * Contains \Drupal\search_api\Form\IndexFacetsForm.
  */
 
 namespace Drupal\search_api\Form;
 
-use Drupal\Component\Utility\Html;
-use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Entity\EntityForm;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Form\FormStateInterface;
-use Drupal\search_api\Processor\ProcessorInterface;
-use Drupal\search_api\Processor\ProcessorPluginManager;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Provides a form for configuring the processors of a search index.
  */
-class IndexProcessorsForm extends EntityForm {
+class IndexFacetsForm extends EntityForm {
 
   /**
    * The index being configured.
@@ -36,23 +32,15 @@ class IndexProcessorsForm extends EntityForm {
   protected $entityManager;
 
   /**
-   * The datasource manager.
-   *
-   * @var \Drupal\search_api\Processor\ProcessorPluginManager
-   */
-  protected $processorPluginManager;
-
-  /**
-   * Constructs an IndexProcessorsForm object.
+   * Constructs an IndexFacetsForm object.
    *
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
-   * @param \Drupal\search_api\Processor\ProcessorPluginManager $processor_plugin_manager
-   *   The processor plugin manager.
    */
-  public function __construct(EntityManagerInterface $entity_manager, ProcessorPluginManager $processor_plugin_manager) {
+  public function __construct(EntityManagerInterface $entity_manager, \Drupal\facet_api\Adapter\AdapterPluginManager $adapter_manager, \Drupal\facet_api\Searcher\SearcherPluginManager $searcher_manager) {
     $this->entityManager = $entity_manager;
-    $this->processorPluginManager = $processor_plugin_manager;
+    $this->adapterManager = $adapter_manager;
+    $this->searcherManager = $searcher_manager;
   }
 
   /**
@@ -61,9 +49,11 @@ class IndexProcessorsForm extends EntityForm {
   public static function create(ContainerInterface $container) {
     /** @var \Drupal\Core\Entity\EntityManagerInterface $entity_manager */
     $entity_manager = $container->get('entity.manager');
-    /** @var \Drupal\search_api\Processor\ProcessorPluginManager $processor_plugin_manager */
-    $processor_plugin_manager = $container->get('plugin.manager.search_api.processor');
-    return new static($entity_manager, $processor_plugin_manager);
+    /** @var \Drupal\facet_api\AdapterManager $adapter_manager */
+    $adapter_manager = $container->get('plugin.manager.facet_api.adapter');
+    /** @var \Drupal\facet_api\Searcher\SearcherPluginManager $searcher_manager */
+    $searcher_manager = $container->get('plugin.manager.facet_api.searcher');
+    return new static($entity_manager, $adapter_manager, $searcher_manager);
   }
 
   /**
@@ -77,216 +67,159 @@ class IndexProcessorsForm extends EntityForm {
    * {@inheritdoc}
    */
   public function form(array $form, FormStateInterface $form_state) {
-    $form['#attached']['library'][] = 'search_api/drupal.search_api.admin_css';
-
-    // Retrieve lists of all processors, and the stages and weights they have.
-    if (!$form_state->has('processors')) {
-      $all_processors = $this->entity->getProcessors(FALSE);
-      $sort_processors = function (ProcessorInterface $a, ProcessorInterface $b) {
-        return strnatcasecmp($a->label(), $b->label());
-      };
-      uasort($all_processors, $sort_processors);
+    $index = $this->entity;
+    if (!$index->isServerEnabled()) {
+      return array('#markup' => t('Since this index is at the moment disabled, no facets can be activated.'));
     }
-    else {
-      $all_processors = $form_state->get('processors');
+    if (!$index->getServer()->supportsFeature('search_api_facets')) {
+      return array('#markup' => t('This index uses a server that does not support facet functionality.'));
     }
 
-    $stages = $this->processorPluginManager->getProcessingStages();
-    $processors_by_stage = array();
-    foreach ($stages as $stage => $definition) {
-      $processors_by_stage[$stage] = $this->entity->getProcessorsByStage($stage, FALSE);
-    }
+    // Instantiates adapter, loads realm.
+    $adapter = $this->adapterManager->getDefinition('search_api');
 
-    $processor_settings = $this->entity->getOption('processors');
+    // @todo inject realmManager to load realms. Look at the DataSourceDerivative
+    $realm_name = $index->getServerId() . ':' . $index->id();
 
-    $form['#tree'] = TRUE;
-    $form['#attached']['library'][] = 'search_api/drupal.search_api.index-active-formatters';
-    $form['#title'] = $this->t('Manage processors for search index %label', array('%label' => $this->entity->label()));
-    $form['description']['#markup'] = '<p>' . $this->t('Configure processors which will pre- and post-process data at index and search time.') . '</p>';
+    $realm = $this->searcherManager->getInstance();
+    /*$realm = facetapi_realm_load($realm_name);
+    // @todo inject facetManager to get Facet Info from Searchers
+    $facet_info = facetapi_get_facet_info($searcher);
 
-    // Add the list of processors with checkboxes to enable/disable them.
-    $form['status'] = array(
-      '#type' => 'fieldset',
-      '#title' => $this->t('Enabled'),
-      '#attributes' => array('class' => array(
-        'search-api-status-wrapper',
-      )),
+    $form['#facetapi'] = array(
+      'adapter' => $adapter,
+      'realm' => $realm,
+      'facet_info' => $facet_info
     );
-    foreach ($all_processors as $processor_id => $processor) {
-      $clean_css_id = Html::cleanCssIdentifier($processor_id);
-      $form['status'][$processor_id] = array(
-        '#type' => 'checkbox',
-        '#title' => $processor->label(),
-        '#default_value' => $processor->isLocked() || !empty($processor_settings[$processor_id]),
-        '#description' => $processor->getDescription(),
-        '#attributes' => array(
-          'class' => array(
-            'search-api-processor-status-' . $clean_css_id,
-          ),
-          'data-id' => $clean_css_id,
-        ),
-        '#disabled' => $processor->isLocked(),
-        '#access' => !$processor->isHidden(),
-      );
-    }
 
-    $form['weights'] = array(
-      '#type' => 'fieldset',
-      '#title' => t('Processor order'),
+    $form['description'] = array(
+      '#prefix' => '<div class="facetapi-realm-description">',
+      '#markup' => filter_xss_admin($realm['description']),
+      '#suffix' => "</div>\n",
     );
-    // Order enabled processors per stage.
-    foreach ($stages as $stage => $description) {
-      $form['weights'][$stage] = array (
-        '#type' => 'fieldset',
-        '#title' => $description['label'],
-        '#attributes' => array('class' => array(
-          'search-api-stage-wrapper',
-          'search-api-stage-wrapper-' . Html::cleanCssIdentifier($stage),
-        )),
-      );
-      $form['weights'][$stage]['order'] = array(
-        '#type' => 'table',
-      );
-      $form['weights'][$stage]['order']['#tabledrag'][] = array(
-        'action' => 'order',
-        'relationship' => 'sibling',
-        'group' => 'search-api-processor-weight-' . Html::cleanCssIdentifier($stage),
+
+    $form['performance'] = array(
+      '#prefix' => '<div class="facetapi-performance-note">',
+      '#markup' => t('For performance reasons, you should only enable facets that you intend to have available to users on the search page.'),
+      '#suffix' => "</div>\n",
+    );
+
+    $form['table'] = array(
+      '#theme' => 'facetapi_realm_settings_table',
+      '#facetapi' => &$form['#facetapi'],
+      'operations' => array('#tree' => TRUE),
+      'weight' => array('#tree' => TRUE),
+    );
+
+    // Builds "enabled_facets" options.
+    $options = $default_value = array();
+    foreach ($form['#facetapi']['facet_info'] as $facet_name => $facet) {
+      $settings = $adapter->getFacetSettings($facet, $realm);
+      $global_settings = $adapter->getFacetSettingsGlobal($facet);
+
+      // Builds array of operations to use in the dropbutton.
+      $operations = array();
+      $operations[] = array(
+        'title' => t('Configure display'),
+        'href' => facetapi_get_settings_path($searcher, $realm['name'], $facet_name, 'edit')
       );
-    }
-    foreach ($processors_by_stage as $stage => $processors) {
-      /** @var \Drupal\search_api\Processor\ProcessorInterface $processor */
-      foreach ($processors as $processor_id => $processor) {
-        $weight = isset($processor_settings[$processor_id]['weights'][$stage])
-          ? $processor_settings[$processor_id]['weights'][$stage]
-          : $processor->getDefaultWeight($stage);
-        if ($processor->isHidden()) {
-          $form['processors'][$processor_id]['weights'][$stage] = array(
-            '#type' => 'value',
-            '#value' => $weight,
-          );
-          continue;
-        }
-        $form['weights'][$stage]['order'][$processor_id]['#attributes']['class'][] = 'draggable';
-        $form['weights'][$stage]['order'][$processor_id]['#attributes']['class'][] = 'search-api-processor-weight--' . Html::cleanCssIdentifier($processor_id);
-        $form['weights'][$stage]['order'][$processor_id]['#weight'] = $weight;
-        $form['weights'][$stage]['order'][$processor_id]['label'] = array(
-          '#markup' => SafeMarkup::checkPlain($processor->label()),
+      if ($facet['dependency plugins']) {
+        $operations[] = array(
+          'title' => t('Configure dependencies'),
+          'href' => facetapi_get_settings_path($searcher, $realm['name'], $facet_name, 'dependencies')
         );
-        $form['weights'][$stage]['order'][$processor_id]['weight'] = array(
-          '#type' => 'weight',
-          '#title' => $this->t('Weight for processor %title', array('%title' => $processor->label())),
-          '#title_display' => 'invisible',
-          '#default_value' => $weight,
-          '#parents' => array('processors', $processor_id, 'weights', $stage),
-          '#attributes' => array('class' => array(
-            'search-api-processor-weight-' . Html::cleanCssIdentifier($stage),
-          )),
+      }
+      if (facetapi_filters_load($facet_name, $searcher, $realm['name'])) {
+        $operations[] = array(
+          'title' => t('Configure filters'),
+          'href' => facetapi_get_settings_path($searcher, $realm['name'], $facet_name, 'filters')
         );
       }
-    }
-
-    // Add vertical tabs containing the settings for the processors. Tabs for
-    // disabled processors are hidden with JS magic, but need to be included in
-    // case the processor is enabled.
-    $form['processor_settings'] = array(
-      '#title' => $this->t('Processor settings'),
-      '#type' => 'vertical_tabs',
-    );
-
-    foreach ($all_processors as $processor_id => $processor) {
-      $processor_form_state = new SubFormState($form_state, array('processors', $processor_id, 'settings'));
-      $processor_form = $processor->buildConfigurationForm($form, $processor_form_state);
-      if ($processor_form) {
-        $form['settings'][$processor_id] = array(
-          '#type' => 'details',
-          '#title' => $processor->label(),
-          '#group' => 'processor_settings',
-          '#parents' => array('processors', $processor_id, 'settings'),
-          '#attributes' => array('class' => array(
-            'search-api-processor-settings-' . Html::cleanCssIdentifier($processor_id),
-          )),
+      $operations[] = array(
+        'title' => t('Export configuration'),
+        'href' => facetapi_get_settings_path($searcher, $realm['name'], $facet_name, 'export')
+      );
+      if (facetapi_is_overridden($settings) || facetapi_is_overridden($global_settings)) {
+        $operations[] = array(
+          'title' => t('Revert configuration'),
+          'href' => facetapi_get_settings_path($searcher, $realm['name'], $facet_name, 'revert')
         );
-        $form['settings'][$processor_id] += $processor_form;
       }
-    }
 
-    return $form;
-  }
+      $form['table']['operations'][$facet_name] = array(
+        '#theme' => 'links__ctools_dropbutton',
+        '#links' => $operations,
+        '#attributes' => array(
+          'class' => array('inline', 'links', 'actions', 'horizontal', 'right')
+        ),
+      );
 
-  /**
-   * {@inheritdoc}
-   */
-  public function validateForm(array &$form, FormStateInterface $form_state) {
-    parent::validateForm($form, $form_state);
-
-    $values = $form_state->getValues();
-    /** @var \Drupal\search_api\Processor\ProcessorInterface[] $processors */
-    $processors = $this->entity->getProcessors(FALSE);
-
-    // Iterate over all processors that have a form and are enabled.
-    foreach ($form['settings'] as $processor_id => $processor_form) {
-      if (!empty($values['status'][$processor_id])) {
-        $processor_form_state = new SubFormState($form_state, array('processors', $processor_id, 'settings'));
-        $processors[$processor_id]->validateConfigurationForm($form['settings'][$processor_id], $processor_form_state);
-      }
-    }
-  }
+      // Adds weight if sortable.
+      if ($realm['sortable']) {
 
-  /**
-   * {@inheritdoc}
-   */
-  public function submitForm(array &$form, FormStateInterface $form_state) {
-    $values = $form_state->getValues();
-    $new_settings = array();
-
-    // Store processor settings.
-    // @todo Go through all available processors, enable/disable with method on
-    //   processor plugin to allow reaction.
-    /** @var \Drupal\search_api\Processor\ProcessorInterface $processor */
-    $processors = $this->entity->getProcessors(FALSE);
-    foreach ($processors as $processor_id => $processor) {
-      if (empty($values['status'][$processor_id])) {
-        continue;
-      }
-      $new_settings[$processor_id] = array(
-        'processor_id' => $processor_id,
-        'weights' => array(),
-        'settings' => array(),
-      );
-      $processor_values = $values['processors'][$processor_id];
-      if (!empty($processor_values['weights'])) {
-        $new_settings[$processor_id]['weights'] = $processor_values['weights'];
-      }
-      if (isset($form['settings'][$processor_id])) {
-        $processor_form_state = new SubFormState($form_state, array('processors', $processor_id, 'settings'));
-        $processor->submitConfigurationForm($form['settings'][$processor_id], $processor_form_state);
-        $new_settings[$processor_id]['settings'] = $processor->getConfiguration();
+        $form['#facetapi']['facet_info'][$facet_name]['weight'] = $settings->settings['weight'];
+        $form['table']['weight'][$facet_name] = array(
+          '#type' => 'select',
+          '#title' => t('Weight for @title', array('@title' => $facet['label'])),
+          '#title_display' => 'invisible',
+          '#options' => drupal_map_assoc(range(-50, 50)),
+          '#default_value' => $settings->settings['weight'],
+          '#attributes' => array('class' => array('facetapi-facet-weight')),
+        );
       }
+
+      $options[$facet_name] = '';
+      $default_value[$facet_name] = (!$settings->enabled) ? 0 : $facet_name;
     }
 
-    // Sort the processors so we won't have unnecessary changes.
-    ksort($new_settings);
-    if (!$this->entity->getOption('processors', array()) !== $new_settings) {
-      $this->entity->setOption('processors', $new_settings);
-      $this->entity->save();
-      $this->entity->reindex();
-      drupal_set_message($this->t('The indexing workflow was successfully edited. All content was scheduled for reindexing so the new settings can take effect.'));
+    // Sorts by the weight appended above.
+    uasort($form['#facetapi']['facet_info'], 'drupal_sort_weight');
+
+    $form['table']['enabled_facets'] = array(
+      '#type' => 'checkboxes',
+      '#options' => $options,
+      '#default_value' => $default_value,
+    );
+
+    // Checks whether block caching is enabled, sets description accordingly.
+    if (!$disabled = (module_implements('node_grants') || !variable_get('block_cache', FALSE))) {
+      $description = t('Configure the appropriate cache setting for facet blocks.');
     }
     else {
-      drupal_set_message($this->t('No values were changed.'));
+      $description = t(
+        'To enable block caching, visit the <a href="@performance-page">performance page</a>.',
+        array('@performance-page' => url('admin/config/development/performance', array('query' => array('destination' => current_path()))))
+      );
     }
-  }
+    $form['block_cache'] = array(
+      '#type' => 'select',
+      '#access' => ('block' == $realm_name),
+      '#title' => t('Block cache settings'),
+      '#disabled' => $disabled,
+      '#options' => array(
+        DRUPAL_NO_CACHE => t('Do not cache'),
+        DRUPAL_CACHE_PER_ROLE | DRUPAL_CACHE_PER_PAGE => t('Per role'),
+        DRUPAL_CACHE_PER_USER | DRUPAL_CACHE_PER_PAGE => t('Per user'),
+      ),
+      '#default_value' => variable_get('facetapi:block_cache:' . $searcher, DRUPAL_NO_CACHE),
+      '#description' => $description,
+    );
 
-  /**
-   * {@inheritdoc}
-   */
-  protected function actions(array $form, FormStateInterface $form_state) {
-    $actions = parent::actions($form, $form_state);
+    $form['actions'] = array(
+      '#type' => 'actions',
+      '#weight' => 20,
+    );
 
-    // We don't have a "delete" action here.
-    unset($actions['delete']);
+    $form['actions']['submit'] = array(
+      '#type' => 'submit',
+      '#value' => t('Save configuration'),
+    );
 
-    return $actions;
+    $form['#submit'][] = 'facetapi_realm_settings_form_submit';
+
+    return $form;
+    */
   }
 
+
 }
diff --git a/src/Form/IndexFieldsForm.php b/src/Form/IndexFieldsForm.php
index e53ecd6..404c995 100644
--- a/src/Form/IndexFieldsForm.php
+++ b/src/Form/IndexFieldsForm.php
@@ -199,7 +199,6 @@ class IndexFieldsForm extends EntityForm {
       );
       $build['fields'][$key]['boost'] = array(
         '#type' => 'select',
-        '#options' => $boosts,
         '#default_value' => sprintf('%.1f', $field->getBoost()),
         '#states' => array(
           'visible' => array(
@@ -210,6 +209,12 @@ class IndexFieldsForm extends EntityForm {
       foreach ($fulltext_types as $type) {
         $build['fields'][$key]['boost']['#states']['visible'][$css_key . '-type'][] = array('value' => $type);
       }
+
+      $build['fields'][$key]['facet'] = array(
+        '#type' => 'checkbox',
+        '#default_value' => $field->isFaceted(),
+      );
+
       $build['fields'][$key]['#disabled'] = $field->isLocked();
       $build['fields'][$key]['#access'] = !$field->isHidden();
     }
@@ -261,6 +266,7 @@ class IndexFieldsForm extends EntityForm {
         $field->setType($fields[$field_id]['type']);
         $field->setBoost($fields[$field_id]['boost']);
         $field->setIndexed((bool) $fields[$field_id]['indexed'], TRUE);
+        $field->setFaceted((bool) $fields[$field_id]['facet'], TRUE);
       }
     }
 
diff --git a/src/Item/Field.php b/src/Item/Field.php
index b961d2b..2858794 100644
--- a/src/Item/Field.php
+++ b/src/Item/Field.php
@@ -53,6 +53,13 @@ class Field implements \IteratorAggregate, FieldInterface {
   protected $boost;
 
   /**
+   * The state of this field towards the facet implementation.
+   *
+   * @var bool
+   */
+  protected $faceted;
+
+  /**
    * {@inheritdoc}
    */
   public function getType() {
@@ -156,6 +163,35 @@ class Field implements \IteratorAggregate, FieldInterface {
   /**
    * {@inheritdoc}
    */
+  public function setFaceted($faceted, $notify = FALSE) {
+    $faceted = (bool) $faceted;
+    $this->faceted = $faceted;
+    if ($notify) {
+      $fields = $this->index->getOption('fields', array());
+      if (isset($fields[$this->fieldIdentifier])) {
+        $fields[$this->fieldIdentifier]['faceted'] = $faceted;
+        $this->index->setOption('fields', $fields);
+      }
+    }
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isFaceted() {
+    if (!isset($this->faceted)) {
+      $fields = $this->index->getOption('fields', array());
+      if (isset($fields[$this->fieldIdentifier])) {
+        $this->faceted = isset($fields[$this->fieldIdentifier]['boost']) ? (bool) $fields[$this->fieldIdentifier]['faceted'] : false;
+      }
+    }
+    return $this->faceted;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getBoost() {
     if (!isset($this->boost)) {
       $fields = $this->index->getOption('fields', array());
diff --git a/src/Item/FieldInterface.php b/src/Item/FieldInterface.php
index c12c5c2..5f41966 100644
--- a/src/Item/FieldInterface.php
+++ b/src/Item/FieldInterface.php
@@ -118,6 +118,27 @@ interface FieldInterface extends GenericFieldInterface, \Traversable {
   public function getBoost();
 
   /**
+   * Sets whether this field is enabled to render facets from the results.
+   *
+   * @param bool $faceted
+   *   The facet state of this field.
+   * @param bool $notify
+   *   (optional) Whether to notify the index of the change, i.e., set the field
+   *   to faceted in its options, too.
+   *
+   * @return $this
+   */
+  public function setFaceted($faceted, $notify = FALSE);
+
+  /**
+   * Retrieves wether or not the the field is enabled to render facets.
+   *
+   * @return bool $faceted
+   *   The facet state of this field.
+   */
+  public function isFaceted();
+
+  /**
    * Sets the field's boost value.
    *
    * @param float $boost
diff --git a/src/Plugin/facet_api/adapter/Adapter.php b/src/Plugin/facet_api/adapter/Adapter.php
index 58e956e..ebe04ee 100644
--- a/src/Plugin/facet_api/adapter/Adapter.php
+++ b/src/Plugin/facet_api/adapter/Adapter.php
@@ -1,9 +1,11 @@
 <?php
 /**
- * Contains Drupal\facet_api\Plugin\TestAdapter
+ * Contains Drupal\search_api\Plugin\facet_api\adapter\Adapter
  */
 
-namespace Drupal\search_api\Plugin\search_api\adapter;
+namespace Drupal\search_api\Plugin\facet_api\adapter;
+
+use Drupal\facet_api\Adapter\AdapterPluginBase;
 
 /**
  * @FacetApiAdapter(
@@ -12,7 +14,7 @@ namespace Drupal\search_api\Plugin\search_api\adapter;
  *   description = @Translation("Search API Class for facet_api")
  * )
  */
-class SearchApiFacetAdapter extends AdapterBase {
+class Adapter extends AdapterPluginBase {
 
   /**
    * Returns a boolean flagging whether $this->searcher['searcher'] executed a