Issue #2915758 by justanothermark, larowlan: Add Views contextual filter for 'is Sibling of'

config/schema/entity_hierarchy.views.schema.yml

@@ -15,8 +15,19 @@ views.argument.entity_hierarchy_argument_is_parent_of_entity:
       type: integer
       label: 'Depth'
 
+views.argument.entity_hierarchy_argument_is_sibling_of_entity:
+  type: views_argument
+  label: 'Sibling entities'
+  mapping:
+    depth:
+      type: integer
+      label: 'Depth'
+
 views.argument.entity_hierarchy_argument_is_parent_of_entity_revision:
   type: views.argument.entity_hierarchy_argument_is_parent_of_entity
 
 views.argument.entity_hierarchy_argument_is_child_of_entity_revision:
   type: views.argument.entity_hierarchy_argument_is_child_of_entity
+
+views.argument.entity_hierarchy_argument_is_sibling_of_entity_revision:
+  type: views.argument.entity_hierarchy_argument_is_sibling_of_entity

entity_hierarchy.views.inc

@@ -76,6 +76,15 @@ function entity_hierarchy_views_data() {
           'id' => $has_revisions ? 'entity_hierarchy_argument_is_parent_of_entity_revision' : 'entity_hierarchy_argument_is_parent_of_entity',
         ],
       ];
+      // Contextual filter for filtering to sibling of a given child.
+      $data[$table_name]['is_sibling'] = [
+        'title' => t('Hierarchy: Is Sibling of'),
+        'help' => t('Limit to sibling of given entity'),
+        'real field' => 'left_pos',
+        'argument' => [
+          'id' => $has_revisions ? 'entity_hierarchy_argument_is_sibling_of_entity_revision' : 'entity_hierarchy_argument_is_sibling_of_entity',
+        ],
+      ];
       // Sorting and filtering on depth.
       $data[$table_name]['depth'] = [
         'title' => t('Hierarchy depth'),

src/Plugin/views/argument/HierarchyIsSiblingOfEntity.php

+<?php
+
+namespace Drupal\entity_hierarchy\Plugin\views\argument;
+
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Argument to limit to parent of an entity.
+ *
+ * @ingroup views_argument_handlers
+ *
+ * @ViewsArgument("entity_hierarchy_argument_is_sibling_of_entity")
+ */
+class HierarchyIsSiblingOfEntity extends EntityHierarchyArgumentPluginBase {
+
+  /**
+   * Set up the query for this argument.
+   *
+   * The argument sent may be found at $this->argument.
+   */
+  public function query($group_by = FALSE) {
+    $this->ensureMyTable();
+    // Load the actual entity.
+    $filtered = FALSE;
+    if ($entity = $this->loadEntity()) {
+      $stub = $this->nodeKeyFactory->fromEntity($entity);
+      if ($node = $this->getTreeStorage()->findParent($stub)) {
+        // Query between a range with fixed depth, excluding the original node.
+        $filtered = TRUE;
+        $expression = "$this->tableAlias.$this->realField BETWEEN :lower and :upper AND $this->tableAlias.$this->realField <> :lower AND $this->tableAlias.depth = :depth AND $this->tableAlias.id != :self";
+        $arguments = [
+          ':lower' => $node->getLeft(),
+          ':upper' => $node->getRight(),
+          ':depth' => $node->getDepth() + 1,
+          ':self' => $stub->getId(),
+        ];
+
+        $this->query->addWhereExpression(0, $expression, $arguments);
+      }
+    }
+    // The parent entity doesn't exist, or isn't in the tree and hence has no
+    // children.
+    if (!$filtered) {
+      // Add a killswitch.
+      $this->query->addWhereExpression(0, '1 <> 1');
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
+    parent::buildOptionsForm($form, $form_state);
+    unset($form['depth']);
+  }
+
+}

src/Plugin/views/argument/HierarchyIsSiblingOfEntityRevision.php

+<?php
+
+namespace Drupal\entity_hierarchy\Plugin\views\argument;
+
+/**
+ * Argument to limit to parent of a revision.
+ *
+ * @ingroup views_argument_handlers
+ *
+ * @ViewsArgument("entity_hierarchy_argument_is_sibling_of_entity_revision")
+ */
+class HierarchyIsSiblingOfEntityRevision extends HierarchyIsSiblingOfEntity {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function loadEntity() {
+    $storage = $this->entityTypeManager->getStorage($this->getEntityType());
+    return $storage->loadRevision($this->argument) ?: $storage->load($this->argument);
+  }
+
+}

tests/modules/entity_hierarchy_test_views/config/install/views.view.entity_hierarchy_test_children_view.yml

@@ -327,3 +327,55 @@ display:
         - url
         - url.query_args
       tags: {  }
+  block_4:
+    display_plugin: block
+    id: block_4
+    display_title: Block
+    position: 3
+    display_options:
+      display_extenders: {  }
+      arguments:
+        is_parent:
+          id: is_sibling
+          table: nested_set_parents_entity_test
+          field: is_sibling
+          relationship: none
+          group_type: group
+          admin_label: ''
+          default_action: ignore
+          exception:
+            value: all
+            title_enable: false
+            title: All
+          title_enable: false
+          title: ''
+          default_argument_type: fixed
+          default_argument_options:
+            argument: ''
+          default_argument_skip_url: false
+          summary_options:
+            base_path: ''
+            count: true
+            items_per_page: 25
+            override: false
+          summary:
+            sort_order: asc
+            number_of_records: 0
+            format: default_summary
+          specify_validation: true
+          validate:
+            type: none
+            fail: 'not found'
+          validate_options: {  }
+          plugin_id: entity_hierarchy_argument_is_sibling_of_entity
+      defaults:
+        arguments: false
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - entity_test_view_grants
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+      tags: {  }

tests/src/Kernel/ViewsIntegrationTest.php

@@ -162,4 +162,38 @@ class ViewsIntegrationTest extends EntityHierarchyKernelTestBase {
     $this->assertIdenticalResultset($executable, $expected, ['name' => 'name', 'id' => 'id']);
   }
 
+  /**
+   * Tests views sibling integration.
+   */
+  public function testViewsIntegrationSiblings() {
+    $children = $this->createChildEntities($this->parent->id(), 3);
+    $child = reset($children);
+    $this->createChildEntities($child->id(), 5);
+    // Tree is as follows
+    // 1     : Parent
+    // - 4   : Child 3
+    // - 3   : Child 2
+    // - 2   : Child 1
+    // - - 9 : Child 5
+    // - - 8 : Child 4
+    // - - 7 : Child 3
+    // - - 6 : Child 2
+    // - - 5 : Child 1
+    // Test showing single hierarchy.
+    $expected = [
+      [
+        'name' => 'Child 3',
+        'id' => 4,
+      ],
+      [
+        'name' => 'Child 2',
+        'id' => 3,
+      ],
+    ];
+    $executable = Views::getView('entity_hierarchy_test_children_view');
+    $executable->preview('block_4', [$child->id()]);
+    $this->assertCount(2, $executable->result);
+    $this->assertIdenticalResultset($executable, $expected, ['name' => 'name', 'id' => 'id']);
+  }
+
 }