Issue #2862703 by alan-ps: Add Reset Facets Button to summary

modules/facets_summary/src/Plugin/facets_summary/processor/ResetFacetsProcessor.php

+<?php
+
+namespace Drupal\facets_summary\Plugin\facets_summary\processor;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Link;
+use Drupal\facets_summary\FacetsSummaryInterface;
+use Drupal\facets_summary\Processor\BuildProcessorInterface;
+use Drupal\facets_summary\Processor\ProcessorPluginBase;
+
+/**
+ * Provides a processor that allows to reset facet filters.
+ *
+ * @SummaryProcessor(
+ *   id = "reset_facets",
+ *   label = @Translation("Adds reset facets link."),
+ *   description = @Translation("When checked, this facet will add a link to reset enabled facets."),
+ *   stages = {
+ *     "build" = 50
+ *   }
+ * )
+ */
+class ResetFacetsProcessor extends ProcessorPluginBase implements BuildProcessorInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build(FacetsSummaryInterface $facets_summary, array $build, array $facets) {
+    $conf = $facets_summary->getProcessorConfigs()[$this->getPluginId()];
+
+    // Do nothing if there are no selected facets or reset text is empty.
+    if (empty($build['#items']) || empty($conf['settings']['link_text'])) {
+      return $build;
+    }
+
+    $request = \Drupal::requestStack()->getMasterRequest();
+    $query_params = $request->query->all();
+
+    // Bypass all active facets and remove them from the query parameters array.
+    foreach ($facets as $facet) {
+      $url_alias = $facet->getUrlAlias();
+      $filter_key = $facet->getFacetSourceConfig()->getFilterKey() ?: 'f';
+
+      if (isset($query_params[$filter_key])) {
+        foreach ($query_params[$filter_key] as $delta => $param) {
+          if (strpos($param, $url_alias . ':') !== FALSE) {
+            unset($query_params[$filter_key][$delta]);
+          }
+        }
+
+        if (!$query_params[$filter_key]) {
+          unset($query_params[$filter_key]);
+        }
+      }
+    }
+
+    // Lets use any first facet to get correct url.
+    $results = reset($facets)->getResults();
+
+    /** @var  \Drupal\Core\Url $first_item_url */
+    $first_item_url = reset($results)->getUrl();
+    $first_item_url = clone ($first_item_url);
+    $first_item_url->setOptions(['query' => $query_params]);
+
+    $item = (new Link($conf['settings']['link_text'], $first_item_url))->toRenderable();
+    array_unshift($build['#items'], $item);
+    return $build;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state, FacetsSummaryInterface $facets_summary) {
+    // By default, there should be no config form.
+    $processors = $facets_summary->getProcessors();
+    $config = isset($processors[$this->getPluginId()]) ? $processors[$this->getPluginId()] : NULL;
+
+    $build['link_text'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Reset facets link text'),
+      '#default_value' => !is_null($config) ? $config->getConfiguration()['link_text'] : $this->defaultConfiguration()['link_text'],
+    ];
+
+    return $build;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultConfiguration() {
+    return ['link_text' => ''];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isHidden() {
+    return FALSE;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isLocked() {
+    return FALSE;
+  }
+
+}

modules/facets_summary/tests/src/Functional/IntegrationTest.php

@@ -3,6 +3,7 @@
 namespace Drupal\Tests\facets_summary\Functional;
 
 use Drupal\Tests\facets\Functional\FacetsTestBase;
+use Drupal\facets_summary\Entity\FacetsSummary;
 use Drupal\views\Views;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -86,6 +87,8 @@ class IntegrationTest extends FacetsTestBase {
     // Enable a facet and check it's status after saving.
     $this->drupalPostForm(NULL, ['facets[llama][checked]' => TRUE], 'Save');
     $this->assertFieldChecked('edit-facets-llama-checked');
+
+    $this->configureResetFacetsProcessor();
   }
 
   /**
@@ -170,6 +173,8 @@ class IntegrationTest extends FacetsTestBase {
       ->findById('block-' . $block->id())
       ->findAll('css', 'li');
     $this->assertCount(2, $list_items);
+
+    $this->checkResetFacetsProcessor();
   }
 
   /**
@@ -204,4 +209,72 @@ class IntegrationTest extends FacetsTestBase {
     $this->assertEquals('none', $current_cache['type']);
   }
 
+  /**
+   * Tests configuring reset facets processor.
+   */
+  protected function configureResetFacetsProcessor() {
+    $this->assertSession()->checkboxNotChecked('edit-facets-summary-settings-reset-facets-status');
+    $this->drupalPostForm(NULL, ['facets_summary_settings[reset_facets][status]' => TRUE], 'Save');
+    $this->assertSession()->checkboxChecked('edit-facets-summary-settings-reset-facets-status');
+    $this->assertSession()->pageTextContains(t('Facets Summary Owl has been updated.'));
+
+    $this->assertSession()->fieldExists('facets_summary_settings[reset_facets][settings][link_text]');
+    $this->drupalPostForm(NULL, ['facets_summary_settings[reset_facets][settings][link_text]' => 'Reset facets'], 'Save');
+    $this->assertSession()->pageTextContains(t('Facets Summary Owl has been updated.'));
+    $this->assertSession()->fieldValueEquals('facets_summary_settings[reset_facets][settings][link_text]', 'Reset facets');
+  }
+
+  /**
+   * Tests reset facets processor.
+   */
+  protected function checkResetFacetsProcessor() {
+    // Create new facets summary.
+    FacetsSummary::create([
+      'id' => 'reset_facets',
+      'name' => t('Reset facets summary'),
+      'facet_source_id' => 'search_api:views_page__search_api_test_view__page_1',
+      'facets' => [
+        'giraffe' => [
+          'checked' => 1,
+          'label' => 'Giraffe',
+          'separator' => ',',
+          'weight' => 0,
+          'show_count' => 0,
+        ],
+        'llama' => [
+          'checked' => 1,
+          'label' => 'Llama',
+          'separator' => ',',
+          'weight' => 0,
+          'show_count' => 0,
+        ],
+      ],
+      'processor_configs' => [
+        'reset_facets' => [
+          'processor_id' => 'reset_facets',
+          'weights' => ['build' => -10],
+          'settings' => ['link_text' => 'Reset facets'],
+        ],
+      ],
+    ])->save();
+
+    // Clear the cache after the new facet summary entity was created.
+    $this->resetAll();
+
+    // Place a block and test reset facets processor.
+    $this->drupalPlaceBlock('facets_summary_block:reset_facets', ['region' => 'footer', 'id' => 'reset-facets']);
+    $this->drupalGet('search-api-test-fulltext');
+
+    $this->assertSession()->pageTextContains(t('Displaying 5 search results'));
+    $this->assertSession()->pageTextNotContains(t('Reset facets'));
+
+    $this->clickLink('apple');
+    $this->assertSession()->pageTextContains(t('Displaying 2 search results'));
+    $this->assertSession()->pageTextContains(t('Reset facets'));
+
+    $this->clickLink(t('Reset facets'));
+    $this->assertSession()->pageTextContains(t('Displaying 5 search results'));
+    $this->assertSession()->pageTextNotContains(t('Reset facets'));
+  }
+
 }