src/FacetManager/DefaultFacetManager.php

@@ -108,15 +108,11 @@ class DefaultFacetManager {
   protected $facetSourceId;
 
   /**
-   * Set the search id.
+   * The entity storage for facets.
    *
-   * @param string $facet_source_id
-   *   The id of the facet source.
+   * @var \Drupal\Core\Entity\EntityStorageInterface|object
    */
-  public function setFacetSourceId($facet_source_id) {
-    $this->facetSourceId = $facet_source_id;
-  }
-
+  protected $facetStorage;
   /**
    * Constructs a new instance of the DefaultFacetManager.
    *
@@ -136,13 +132,23 @@ class DefaultFacetManager {
     $this->widgetPluginManager = $widget_plugin_manager;
     $this->facetSourcePluginManager = $facet_source_manager;
     $this->processorPluginManager = $processor_plugin_manager;
-    $this->facet_storage = $entity_type_manager->getStorage('facets_facet');
+    $this->facetStorage = $entity_type_manager->getStorage('facets_facet');
 
     // Immediately initialize the facets. This can be done directly because the
     // only thing needed is the url.
     $this->initFacets();
   }
 
+  /**
+   * Sets the search id.
+   *
+   * @param string $facet_source_id
+   *   The id of the facet source.
+   */
+  public function setFacetSourceId($facet_source_id) {
+    $this->facetSourceId = $facet_source_id;
+  }
+
   /**
    * Allows the backend to add facet queries to its native query object.
    *
@@ -178,11 +184,11 @@ class DefaultFacetManager {
    *   An array of enabled facets.
    */
   public function getEnabledFacets() {
-    return $this->facet_storage->loadMultiple();
+    return $this->facetStorage->loadMultiple();
   }
 
   /**
-   * Get the ID of the facet source.
+   * Returns the ID of the facet source.
    *
    * @return string
    *   The id of the facet source.
@@ -209,7 +215,7 @@ class DefaultFacetManager {
   }
 
   /**
-   * Initialize enabled facets.
+   * Initializes enabled facets.
    *
    * In this method all pre-query processors get called and their contents are
    * executed.
@@ -219,23 +225,20 @@ class DefaultFacetManager {
       $this->facets = $this->getEnabledFacets();
       foreach ($this->facets as $facet) {
 
-        foreach ($facet->getProcessors() as $processor) {
-          $processor_definition = $processor->getPluginDefinition();
-          if (is_array($processor_definition['stages']) && array_key_exists(ProcessorInterface::STAGE_PRE_QUERY, $processor_definition['stages'])) {
-            /** @var PreQueryProcessorInterface $pre_query_processor */
-            $pre_query_processor = $this->processorPluginManager->createInstance($processor->getPluginDefinition()['id'], ['facet' => $facet]);
-            if (!$pre_query_processor instanceof PreQueryProcessorInterface) {
-              throw new InvalidProcessorException(new FormattableMarkup("The processor @processor has a pre_query definition but doesn't implement the required PreQueryProcessorInterface interface", ['@processor' => $processor_configuration['processor_id']]));
-            }
-            $pre_query_processor->preQuery($facet);
+        foreach ($facet->getProcessorsByStage(ProcessorInterface::STAGE_PRE_QUERY) as $processor) {
+          /** @var PreQueryProcessorInterface $pre_query_processor */
+          $pre_query_processor = $this->processorPluginManager->createInstance($processor->getPluginDefinition()['id'], ['facet' => $facet]);
+          if (!$pre_query_processor instanceof PreQueryProcessorInterface) {
+            throw new InvalidProcessorException(new FormattableMarkup("The processor @processor has a pre_query definition but doesn't implement the required PreQueryProcessorInterface interface", ['@processor' => $processor_configuration['processor_id']]));
           }
+          $pre_query_processor->preQuery($facet);
         }
       }
     }
   }
 
   /**
-   * Build a facet and returns it's render array.
+   * Builds a facet and returns it as a renderable array.
    *
    * This method delegates to the relevant plugins to render a facet, it calls
    * out to a widget plugin to do the actual rendering when results are found.
@@ -283,16 +286,13 @@ class DefaultFacetManager {
     // @see \Drupal\facets\Processor\WidgetOrderProcessorInterface.
     $results = $facet->getResults();
 
-    foreach ($facet->getProcessors() as $processor) {
-      $processor_definition = $this->processorPluginManager->getDefinition($processor->getPluginDefinition()['id']);
-      if (is_array($processor_definition['stages']) && array_key_exists(ProcessorInterface::STAGE_BUILD, $processor_definition['stages'])) {
-        /** @var BuildProcessorInterface $build_processor */
-        $build_processor = $this->processorPluginManager->createInstance($processor->getPluginDefinition()['id'], ['facet' => $facet]);
-        if (!$build_processor instanceof BuildProcessorInterface) {
-          throw new InvalidProcessorException(new FormattableMarkup("The processor @processor has a build definition but doesn't implement the required BuildProcessorInterface interface", ['@processor' => $processor['processor_id']]));
-        }
-        $results = $build_processor->build($facet, $results);
+    foreach ($facet->getProcessorsByStage(ProcessorInterface::STAGE_BUILD) as $processor) {
+      /** @var BuildProcessorInterface $build_processor */
+      $build_processor = $this->processorPluginManager->createInstance($processor->getPluginDefinition()['id'], ['facet' => $facet]);
+      if (!$build_processor instanceof BuildProcessorInterface) {
+        throw new InvalidProcessorException(new FormattableMarkup("The processor @processor has a build definition but doesn't implement the required BuildProcessorInterface interface", ['@processor' => $processor['processor_id']]));
       }
+      $results = $build_processor->build($facet, $results);
     }
     $facet->setResults($results);
 
@@ -336,6 +336,7 @@ class DefaultFacetManager {
    *
    * @param string $facet_id
    *   The id of the facet.
+   *
    * @return \Drupal\facets\FacetInterface|NULL
    *   The updated facet if it exists, NULL otherwise.
    */

src/FacetSource/FacetSourceDeriverBase.php

@@ -82,7 +82,6 @@ abstract class FacetSourceDeriverBase implements ContainerDeriverInterface {
     return isset($derivatives[$derivative_id]) ? $derivatives[$derivative_id] : NULL;
   }
 
-
   /**
    * Compares two plugin definitions according to their labels.
    *

src/FacetSource/FacetSourcePluginBase.php

@@ -7,10 +7,8 @@
 
 namespace Drupal\facets\FacetSource;
 
-use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
 use Drupal\Component\Plugin\PluginBase;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
-use Drupal\facets\Exception\InvalidProcessorException;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Facets\FacetInterface;
 use Drupal\Core\Form\FormStateInterface;

src/FacetSource/FacetSourcePluginInterface.php

@@ -22,7 +22,7 @@ use Drupal\facets\FacetInterface;
 interface FacetSourcePluginInterface extends PluginFormInterface {
 
   /**
-   * Fill in facet data in to the configured facets.
+   * Fills the facet entities with results from the facet source.
    *
    * @param \Drupal\facets\FacetInterface[] $facets
    *   The configured facets.
@@ -30,7 +30,7 @@ interface FacetSourcePluginInterface extends PluginFormInterface {
   public function fillFacetsWithResults($facets);
 
   /**
-   * Get the allowed query types for a given facet for the facet source.
+   * Returns the allowed query types for a given facet for the facet source.
    *
    * @param \Drupal\facets\FacetInterface $facet
    *   The facet we should get query types for.
@@ -86,7 +86,7 @@ interface FacetSourcePluginInterface extends PluginFormInterface {
   public function setSearchKeys($keys);
 
   /**
-   * Gets the search keys, or query text, submitted by the user.
+   * Returns the search keys, or query text, submitted by the user.
    *
    * @return string
    *   The search keys, or query text, submitted by the user.

src/FacetSource/FacetSourcePluginManager.php

@@ -21,15 +21,7 @@ use Drupal\Core\Plugin\DefaultPluginManager;
 class FacetSourcePluginManager extends DefaultPluginManager {
 
   /**
-   * Constructs a FacetSourcePluginManager object.
-   *
-   * @param \Traversable $namespaces
-   *   An object that implements \Traversable which contains the root paths
-   *   keyed by the corresponding namespace to look for plugin implementations.
-   * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
-   *   Cache backend instance to use.
-   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
-   *   The module handler.
+   * {@inheritdoc}
    */
   public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler) {
     parent::__construct('Plugin/facets/facet_source', $namespaces, $module_handler, 'Drupal\facets\FacetSource\FacetSourcePluginInterface', 'Drupal\facets\Annotation\FacetsFacetSource');

src/FacetSourceInterface.php

@@ -23,7 +23,7 @@ interface FacetSourceInterface extends ConfigEntityInterface {
   public function getName();
 
   /**
-   * Gets the filter key for this facet source.
+   * Returns the filter key for this facet source.
    *
    * @return string
    *   The filter key.
@@ -39,7 +39,7 @@ interface FacetSourceInterface extends ConfigEntityInterface {
   public function setFilterKey($filter_key);
 
   /**
-   * Set the processor name to be used.
+   * Sets the processor name to be used.
    *
    * @param string $processor_name
    *   Plugin name of the url processor.

src/Form/FacetDisplayForm.php

@@ -224,7 +224,7 @@ class FacetDisplayForm extends EntityForm {
         $form['facet_settings'][$processor_id]['status'] = array(
           '#type' => 'checkbox',
           '#title' => (string) $processor->getPluginDefinition()['label'],
-          '#default_value' => $processor->isLocked() || !empty($processor->configuration['enabled']),
+          '#default_value' => $processor->isLocked() || !empty($enabled_processors[$processor_id]),
           '#description' => $processor->getDescription(),
           '#attributes' => array(
             'class' => array(
@@ -326,7 +326,6 @@ class FacetDisplayForm extends EntityForm {
       '#default_value' => $facet->getOnlyVisibleWhenFacetSourceIsVisible(),
     ];
 
-    // Behavior for empty facets.
     $empty_behavior_config = $facet->getEmptyBehavior();
     $form['facet_settings']['empty_behavior'] = [
       '#type' => 'radios',
@@ -352,7 +351,6 @@ class FacetDisplayForm extends EntityForm {
       '#default_value' => isset($empty_behavior_config['text_format']) ? $empty_behavior_config['text'] : '',
     ];
 
-    // Query operator.
     $form['facet_settings']['query_operator'] = [
       '#type' => 'radios',
       '#title' => $this->t('Operator'),
@@ -361,6 +359,13 @@ class FacetDisplayForm extends EntityForm {
       '#default_value' => $facet->getQueryOperator(),
     ];
 
+    $form['facet_settings']['exclude'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Exclude'),
+      '#description' => $this->t('Make the search exclude selected facets, instead of restricting it to them.'),
+      '#default_value' => $facet->getExclude(),
+    ];
+
     $form['weights'] = array(
       '#type' => 'details',
       '#title' => t('Advanced settings'),
@@ -393,6 +398,8 @@ class FacetDisplayForm extends EntityForm {
       );
     }
 
+    $processor_settings = $facet->getProcessorConfigs();
+
     // Fill in the containers previously created with the processors that are
     // enabled on the facet.
     foreach ($processors_by_stage as $stage => $processors) {
@@ -498,9 +505,8 @@ class FacetDisplayForm extends EntityForm {
         'weights' => array(),
         'settings' => array(),
       );
-      $processor_values = $values[$form_container_key][$processor_id];
-      if (!empty($processor_values['weights'])) {
-        $new_settings['weights'] = $processor_values['weights'];
+      if (!empty($values['processors'][$processor_id]['weights'])) {
+        $new_settings['weights'] = $values['processors'][$processor_id]['weights'];
       }
       if (isset($form[$form_container_key][$processor_id]['settings'])) {
         $processor_form_state = new SubFormState(
@@ -536,14 +542,16 @@ class FacetDisplayForm extends EntityForm {
     }
     $facet->setEmptyBehavior($empty_behavior_config);
 
-    $facet->setOption('query_operator', $form_state->getValue(['facet_settings', 'query_operator']));
+    $facet->setQueryOperator($form_state->getValue(['facet_settings', 'query_operator']));
+
+    $facet->setExclude($form_state->getValue(['facet_settings', 'exclude']));
 
     $facet->save();
     drupal_set_message(t('Facet %name has been updated.', ['%name' => $facet->getName()]));
   }
 
   /**
-   * Form submission handler for the widget subform.
+   * Handles form submissions for the widget subform.
    */
   public function submitAjaxWidgetConfigForm($form, FormStateInterface $form_state) {
     $form_state->setRebuild();

src/Form/FacetForm.php

@@ -22,7 +22,7 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
 class FacetForm extends EntityForm {
 
   /**
-   * The facet storage controller.
+   * The facet storage.
    *
    * @var \Drupal\Core\Entity\EntityStorageInterface
    */
@@ -74,22 +74,6 @@ class FacetForm extends EntityForm {
     return new static($entity_type_manager, $facet_source_plugin_manager, $processor_plugin_manager);
   }
 
-  /**
-   * Gets the form entity.
-   *
-   * The form entity which has been used for populating form element defaults.
-   * This method is defined on the \Drupal\Core\Entity\EntityFormInterface and
-   * has the same contents there, we only extend to add the correct return type,
-   * this makes IDE's smarter about the other places where we use
-   * $this->getEntity().
-   *
-   * @return \Drupal\facets\FacetInterface
-   *   The current form facet entity.
-   */
-  public function getEntity() {
-    return $this->entity;
-  }
-
   /**
    * Retrieves the facet storage controller.
    *
@@ -174,11 +158,15 @@ class FacetForm extends EntityForm {
     ];
 
     $form['url_alias'] = [
-      '#type' => 'textfield',
+      '#type' => 'machine_name',
       '#title' => $this->t('The name of the facet for usage in URLs'),
       '#default_value' => $facet->getUrlAlias(),
       '#maxlength' => 50,
       '#required' => TRUE,
+      '#machine_name' => [
+        'exists' => [$this->getFacetStorage(), 'load'],
+        'source' => ['name'],
+      ],
     ];
 
     $facet_sources = [];
@@ -230,9 +218,10 @@ class FacetForm extends EntityForm {
   }
 
   /**
-   * Form submission handler for the facet source subform.
+   * Handles form submissions for the facet source subform.
    */
   public function submitAjaxFacetSourceConfigForm($form, FormStateInterface $form_state) {
+    $form_state->setValue('id', NULL);
     $form_state->setRebuild();
   }
 
@@ -271,6 +260,13 @@ class FacetForm extends EntityForm {
    */
   public function validateForm(array &$form, FormStateInterface $form_state) {
     parent::validateForm($form, $form_state);
+
+    $facet_source_id = $form_state->getValue('facet_source_id');
+    if (!is_null($facet_source_id) && $facet_source_id !== '') {
+      /** @var \Drupal\facets\FacetSource\FacetSourcePluginInterface $facet_source */
+      $facet_source = $this->getFacetSourcePluginManager()->createInstance($facet_source_id, ['facet' => $this->getEntity()]);
+      $facet_source->validateConfigurationForm($form, $form_state);
+    }
   }
 
   /**

src/Form/FacetSourceEditForm.php

@@ -44,6 +44,11 @@ class FacetSourceEditForm extends EntityForm {
 
   /**
    * Constructs a FacetSourceEditForm.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   * @param \Drupal\facets\UrlProcessor\UrlProcessorPluginManager $url_processor_plugin_manager
+   *   The url processor plugin manager.
    */
   public function __construct(EntityTypeManagerInterface $entity_type_manager, UrlProcessorPluginManager $url_processor_plugin_manager) {
     $facet_source_storage = $entity_type_manager->getStorage('facets_facet_source');
@@ -61,7 +66,6 @@ class FacetSourceEditForm extends EntityForm {
       $this->setEntity($facet_source);
     }
     else {
-
       // We didn't have a facet source config entity yet for this facet source
       // plugin, so we create it on the fly.
       $facet_source = new FacetSource(
@@ -93,8 +97,7 @@ class FacetSourceEditForm extends EntityForm {
     /** @var \Drupal\facets\FacetSourceInterface $facet_source */
     $facet_source = $this->getEntity();
 
-    // Filter key setting.
-    $form['filterKey'] = [
+    $form['filter_key'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Filter key'),
       '#size' => 20,
@@ -112,13 +115,13 @@ class FacetSourceEditForm extends EntityForm {
       $url_processors[$definition['id']] = $definition['label'];
       $url_processors_description[] = $definition['description'];
     }
-    $form['urlProcessor'] = [
+    $form['url_processor'] = [
       '#type' => 'radios',
       '#title' => $this->t('URL Processor'),
       '#options' => $url_processors,
       '#default_value' => $facet_source->getUrlProcessorName(),
       '#description' => $this->t(
-        'The URL Processor defines the url structure used for this facet source.') . '<br />- ' .  implode('<br>- ', $url_processors_description),
+        'The URL Processor defines the url structure used for this facet source.') . '<br />- ' . implode('<br>- ', $url_processors_description),
     ];
 
     // The parent's form build method will add a save button.

src/Plugin/Block/FacetBlock.php

@@ -49,7 +49,7 @@ class FacetBlock extends BlockBase implements ContainerFactoryPluginInterface {
    *   The plugin implementation definition.
    * @param \Drupal\facets\FacetManager\DefaultFacetManager $facet_manager
    *   The facet manager.
-   * @param \Drupal\Core\Entity\EntityStorageInterface
+   * @param \Drupal\Core\Entity\EntityStorageInterface $facet_storage
    *   The entity storage used for facets.
    */
   public function __construct(array $configuration, $plugin_id, $plugin_definition, DefaultFacetManager $facet_manager, EntityStorageInterface $facet_storage) {
@@ -128,9 +128,9 @@ class FacetBlock extends BlockBase implements ContainerFactoryPluginInterface {
     // impossible to improve this significantly.
     //
     // Note: when using Drupal core's Search module instead of the contributed
-    //       Search API module, the above limitations do not apply, but for now
-    //       it is not considered worth the effort to optimize this just for
-    //       Drupal core's Search.
+    // Search API module, the above limitations do not apply, but for now it is
+    // not considered worth the effort to optimize this just for Drupal core's
+    // Search.
     return 0;
   }
 

src/Plugin/Block/FacetBlockDeriver.php

@@ -37,8 +37,8 @@ class FacetBlockDeriver implements ContainerDeriverInterface {
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container, $base_plugin_id) {
-    $deriver = new static;
-    $deriver->facetStorage = \Drupal::getContainer()->get('entity_type.manager')->getStorage('facets_facet');
+    $deriver = new static($container, $base_plugin_id);
+    $deriver->facetStorage = $container->get('entity_type.manager')->getStorage('facets_facet');
 
     return $deriver;
   }

src/Plugin/Condition/OtherFacet.php

@@ -80,7 +80,7 @@ class OtherFacet extends ConditionPluginBase implements ContainerFactoryPluginIn
    * @param mixed $plugin_definition
    *   The plugin implementation definition.
    */
-  public function __construct(EntityStorageInterface $entity_storage, BlockManager $block_manager, AccountProxyInterface $current_user, DefaultFacetManager $facet_manager,array $configuration, $plugin_id, $plugin_definition) {
+  public function __construct(EntityStorageInterface $entity_storage, BlockManager $block_manager, AccountProxyInterface $current_user, DefaultFacetManager $facet_manager, array $configuration, $plugin_id, $plugin_definition) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
     $this->facetStorage = $entity_storage;
     $this->blockManager = $block_manager;

src/Plugin/facets/facet_source/SearchApiBaseFacetSource.php

@@ -83,7 +83,7 @@ abstract class SearchApiBaseFacetSource extends FacetSourcePluginBase {
    */
   public function getFields() {
     $indexed_fields = [];
-    $fields = $this->index->getFields(TRUE);
+    $fields = $this->index->getFields();
     foreach ($fields as $field) {
       $indexed_fields[$field->getFieldIdentifier()] = $field->getLabel();
     }
@@ -98,16 +98,17 @@ abstract class SearchApiBaseFacetSource extends FacetSourcePluginBase {
     // identifier.
     $field_id = $facet->getFieldIdentifier();
     // Get the Search API Server.
-    $server = $this->index->getServer();
+    $server = $this->index->getServerInstance();
     // Get the Search API Backend.
     $backend = $server->getBackend();
 
-    $fields = $this->index->getFields(TRUE);
+    $fields = $this->index->getFields();
     foreach ($fields as $field) {
       if ($field->getFieldIdentifier() == $field_id) {
         return $this->getQueryTypesForDataType($backend, $field->getType());
       }
     }
+
     throw new InvalidQueryTypeException($this->t("No available query types were found for facet @facet", ['@facet' => $facet->getName()]));
   }
 

src/Plugin/facets/processor/UrlProcessorHandler.php

@@ -17,7 +17,8 @@ use Drupal\facets\Processor\ProcessorPluginBase;
  * The URL processor handler triggers the actual url processor.
  *
  * The URL processor handler allows managing the weight of the actual URL
- * processor per Facet.  This handler will trigger the actual
+ * processor per Facet.  This handler will trigger the actual.
+ *
  * @FacetsUrlProcessor, which can be configured on the Facet source.
  *
  * @FacetsProcessor(
@@ -31,9 +32,13 @@ use Drupal\facets\Processor\ProcessorPluginBase;
  *   locked = true
  * )
  */
-class UrlProcessorHandler extends ProcessorPluginBase implements BuildProcessorInterface, PreQueryProcessorInterface{
+class UrlProcessorHandler extends ProcessorPluginBase implements BuildProcessorInterface, PreQueryProcessorInterface {
 
-  /** @var \Drupal\facets\UrlProcessor\UrlProcessorInterface */
+  /**
+   * The actual url processor used for handing urls.
+   *
+   * @var \Drupal\facets\UrlProcessor\UrlProcessorInterface
+   */
   protected $processor;
 
   /**
@@ -55,7 +60,7 @@ class UrlProcessorHandler extends ProcessorPluginBase implements BuildProcessorI
     $url_processor_name = $fs->getUrlProcessorName();
 
     $manager = \Drupal::getContainer()->get('plugin.manager.facets.url_processor');
-    $this->processor= $manager->createInstance($url_processor_name, ['facet' => $facet]);
+    $this->processor = $manager->createInstance($url_processor_name, ['facet' => $facet]);
   }
 
   /**

src/Plugin/facets/query_type/SearchApiString.php

@@ -29,7 +29,7 @@ use Drupal\facets\Result\Result;
 class SearchApiString extends QueryTypePluginBase {
 
   /**
-   * Holds the backend's native query object.
+   * The backend's native query object.
    *
    * @var \Drupal\search_api\Query\QueryInterface
    */
@@ -47,6 +47,7 @@ class SearchApiString extends QueryTypePluginBase {
     if (!empty($query)) {
       $operator = $this->facet->getQueryOperator();
       $field_identifier = $this->facet->getFieldIdentifier();
+      $exclude = $this->facet->getExclude();
 
       // Copy the query object so we can do an unfiltered query. We need to have
       // this unfiltered results to make sure that the count of a facet is
@@ -65,7 +66,6 @@ class SearchApiString extends QueryTypePluginBase {
         ->execute()
         ->getExtraData('search_api_facets');
 
-
       // Set the options for the actual query.
       $options = &$query->getOptions();
       $options['search_api_facets'][$field_identifier] = array(
@@ -82,7 +82,7 @@ class SearchApiString extends QueryTypePluginBase {
       if (count($active_items)) {
         $filter = $query->createConditionGroup($operator);
         foreach ($active_items as $value) {
-          $filter->addCondition($this->facet->getFieldIdentifier(), $value);
+          $filter->addCondition($this->facet->getFieldIdentifier(), $value, $exclude ? '<>' : '=');
         }
         $query->addConditionGroup($filter);
       }

src/Plugin/facets/url_processor/QueryString.php

@@ -33,7 +33,7 @@ class QueryString extends UrlProcessorPluginBase {
    *
    * @var string
    */
-  protected $url_alias;
+  protected $urlAlias;
 
   /**
    * An array of active filters.
@@ -55,21 +55,20 @@ class QueryString extends UrlProcessorPluginBase {
    * {@inheritdoc}
    */
   public function buildUrls(FacetInterface $facet, array $results) {
-    // Create links for all the values.
-    // First get the current list of get parameters.
-    $get_params = $this->request->query;
-
-    // Set the url alias from the the facet object.
-    $this->url_alias = $facet->getUrlAlias();
-
     // No results are found for this facet, so don't try to create urls.
     if (empty($results)) {
       return [];
     }
 
+    // First get the current list of get parameters.
+    $get_params = $this->request->query;
+
+    // Set the url alias from the the facet object.
+    $this->urlAlias = $facet->getUrlAlias();
+
     /** @var \Drupal\facets\Result\ResultInterface $result */
     foreach ($results as &$result) {
-      $filter_string = $this->url_alias . self::SEPARATOR . $result->getRawValue();
+      $filter_string = $this->urlAlias . self::SEPARATOR . $result->getRawValue();
       $result_get_params = clone $get_params;
 
       $filter_params = $result_get_params->get($this->filterKey, [], TRUE);
@@ -105,18 +104,18 @@ class QueryString extends UrlProcessorPluginBase {
    */
   public function setActiveItems(FacetInterface $facet) {
     // Set the url alias from the the facet object.
-    $this->url_alias = $facet->getUrlAlias();
+    $this->urlAlias = $facet->getUrlAlias();
 
     // Get the filter key of the facet.
-    if (isset($this->activeFilters[$this->url_alias])) {
-      foreach ($this->activeFilters[$this->url_alias] as $value) {
+    if (isset($this->activeFilters[$this->urlAlias])) {
+      foreach ($this->activeFilters[$this->urlAlias] as $value) {
         $facet->setActiveItem(trim($value, '"'));
       }
     }
   }
 
   /**
-   * Initialize the active filters.
+   * Initializes the active filters.
    *
    * Get all the filters that are active. This method only get's all the
    * filters but doesn't assign them to facets. In the processFacet method the

src/Plugin/facets/widget/CheckboxWidget.php

@@ -99,7 +99,7 @@ class CheckboxWidget implements WidgetInterface, FormInterface {
     $results = $facet->getResults();
 
     $configuration = $facet->getWidgetConfigs();
-    $show_numbers = (bool) $configuration['show_numbers'];
+    $show_numbers = (bool) (isset($configuration['show_numbers']) ? $configuration['show_numbers'] : FALSE);
     $form[$facet->getFieldAlias()] = [
       '#type' => 'checkboxes',
       '#title' => $facet->getName(),
@@ -175,4 +175,5 @@ class CheckboxWidget implements WidgetInterface, FormInterface {
     $link->setAbsolute();
     $form_state->setResponse(new RedirectResponse($link->toString()));
   }
+
 }

src/Plugin/facets/widget/LinksWidget.php

@@ -42,7 +42,7 @@ class LinksWidget implements WidgetInterface {
     $items = [];
 
     $configuration = $facet->getWidgetConfigs();
-    $show_numbers = (bool) $configuration['show_numbers'];
+    $show_numbers = empty($configuration['show_numbers']) ? FALSE : (bool) $configuration['show_numbers'];
 
     foreach ($results as $result) {
       // Get the link.
@@ -68,9 +68,9 @@ class LinksWidget implements WidgetInterface {
       '#cache' => [
         'contexts' => [
           'url.path',
-          'url.query_args'
-        ]
-      ]
+          'url.query_args',
+        ],
+      ],
     ];
     return $build;
   }

src/Processor/BuildProcessorInterface.php

@@ -16,7 +16,7 @@ use Drupal\facets\FacetInterface;
 interface BuildProcessorInterface extends ProcessorInterface {
 
   /**
-   * Processor runs before the renderable array is created.
+   * Runs before the renderable array is created.
    *
    * @param \Drupal\facets\FacetInterface $facet
    *   The facet being changed.

src/Processor/PostQueryProcessorInterface.php

@@ -14,7 +14,7 @@ namespace Drupal\facets\Processor;
 interface PostQueryProcessorInterface extends ProcessorInterface {
 
   /**
-   * Processor runs after the query was executed.
+   * Runs after the query was executed.
    *
    * Uses the query results and can alter those results, for example a
    * ValueCallbackProcessor.