Issue #2375879 by jibran, dawehner: Don't filter languages in case it is not needed

core/modules/taxonomy/src/Tests/Views/TaxonomyTermViewTest.php

@@ -12,6 +12,7 @@
 use Drupal\Core\Language\Language;
 use Drupal\language\Entity\ConfigurableLanguage;
 use Drupal\user\Entity\Role;
+use Drupal\views\Views;
 
 /**
  * Tests the taxonomy term view page and its translation.
@@ -118,6 +119,27 @@ public function testTaxonomyTermView() {
     $this->assertText($term->label());
     $this->assertNoText($original_title);
     $this->assertText($translated_title);
+
+    // Uninstall language module and ensure that the language is not part of the
+    // query anymore.
+    // @see \Drupal\views\Plugin\views\filter\LanguageFilter::query()
+    \Drupal::moduleHandler()->uninstall(['content_translation', 'language']);
+
+    $view = Views::getView('taxonomy_term');
+    $view->initDisplay();
+    $view->setArguments([$term->id()]);
+    $view->build();
+    /** @var \Drupal\Core\Database\Query\Select $query */
+    $query = $view->build_info['query'];
+    $tables = $query->getTables();
+
+    // Ensure that the join to node_field_data is not added by default.
+    $this->assertEqual(['node', 'taxonomy_index'], array_keys($tables));
+    // Ensure that the filter to the language column is not there by default.
+    $condition = $query->conditions();
+    // We only want to check the no. of conditions in the query.
+    unset($condition['#conjunction']);
+    $this->assertEqual(1, count($condition));
   }
 
 }

core/modules/views/src/Entity/Render/RendererBase.php

@@ -8,6 +8,7 @@
 namespace Drupal\views\Entity\Render;
 
 use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\views\Plugin\views\query\QueryPluginBase;
 use Drupal\views\ResultRow;
 use Drupal\views\ViewExecutable;
@@ -24,6 +25,13 @@ abstract class RendererBase {
    */
   public $view = NULL;
 
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $languageManager;
+
   /**
    * The type of the entity being rendered.
    *
@@ -43,11 +51,14 @@ abstract class RendererBase {
    *
    * @param \Drupal\views\ViewExecutable $view
    *   The entity row being rendered.
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
+   *   The language manager.
    * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
    *   The entity type.
    */
-  public function __construct(ViewExecutable $view, EntityTypeInterface $entity_type) {
+  public function __construct(ViewExecutable $view, LanguageManagerInterface $language_manager, EntityTypeInterface $entity_type) {
     $this->view = $view;
+    $this->languageManager = $language_manager;
     $this->entityType = $entity_type;
   }
 

core/modules/views/src/Entity/Render/TranslationLanguageRenderer.php

@@ -26,6 +26,11 @@ class TranslationLanguageRenderer extends DefaultLanguageRenderer {
    * {@inheritdoc}
    */
   public function query(QueryPluginBase $query) {
+    // There is no point in getting the language, in case the site is not
+    // multilingual.
+    if (!$this->languageManager->isMultilingual()) {
+      return;
+    }
     // If the data table is defined, we use the translation language as render
     // language, otherwise we fall back to the default entity language, which is
     // stored in the revision table for revisionable entity types.
@@ -67,7 +72,7 @@ public function render(ResultRow $row) {
    * {@inheritdoc}
    */
   protected function getLangcode(ResultRow $row) {
-    return $row->{$this->langcodeAlias};
+    return isset($row->{$this->langcodeAlias}) ? $row->{$this->langcodeAlias} : $this->languageManager->getDefaultLanguage()->getId();
   }
 
 }

core/modules/views/src/Plugin/views/HandlerBase.php

@@ -101,6 +101,13 @@ abstract class HandlerBase extends PluginBase implements ViewsHandlerInterface {
 
   /**
    * Constructs a Handler object.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
    */
   public function __construct(array $configuration, $plugin_id, $plugin_definition) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);

core/modules/views/src/Plugin/views/filter/LanguageFilter.php

@@ -8,7 +8,10 @@
 namespace Drupal\views\Plugin\views\filter;
 
 use Drupal\Core\Language\LanguageInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\views\Plugin\views\PluginBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Provides filtering by language.
@@ -17,7 +20,44 @@
  *
  * @ViewsFilter("language")
  */
-class LanguageFilter extends InOperator {
+class LanguageFilter extends InOperator implements ContainerFactoryPluginInterface {
+
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $languageManager;
+
+  /**
+   * Constructs a new LanguageFilter instance.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
+   *   The language manager.
+   */
+  public function __construct($configuration, $plugin_id, $plugin_definition, LanguageManagerInterface $language_manager) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->languageManager = $language_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('language_manager')
+    );
+  }
 
   /**
    * {@inheritdoc}
@@ -28,4 +68,17 @@ public function getValueOptions() {
       $this->valueOptions = $this->listLanguages(LanguageInterface::STATE_ALL |LanguageInterface::STATE_SITE_DEFAULT | PluginBase::INCLUDE_NEGOTIATED);
     }
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    // Don't filter by language in case the site is not multilingual, because
+    // there is no point in doing so.
+    if (!$this->languageManager->isMultilingual()) {
+      return;
+    }
+
+    parent::query();
+  }
 }

core/modules/views/src/Plugin/views/row/EntityRow.php

@@ -183,7 +183,7 @@ public function summaryTitle() {
   protected function getRenderer() {
     if (!isset($this->renderer)) {
       $class = '\Drupal\views\Entity\Render\\' . Container::camelize($this->options['rendering_language']);
-      $this->renderer = new $class($this->view, $this->entityType);
+      $this->renderer = new $class($this->view, $this->languageManager, $this->entityType);
     }
     return $this->renderer;
   }