Add view of inventory adjustments in an inventory tab on asset pages.

modules/core/ui/views/farm_ui_views.services.yml

@@ -13,6 +13,11 @@ services:
     arguments: [ '@entity_type.manager', '@asset.location' ]
     tags:
       - { name: access_check, applies_to: _asset_children_access }
+  farm_ui_views.asset_inventory_access:
+    class: Drupal\farm_ui_views\Access\FarmInventoryAssetViewsAccessCheck
+    arguments: [ '@entity_type.manager' ]
+    tags:
+      - { name: access_check, applies_to: _asset_inventory_access }
   farm_ui_views.location_assets_access:
     class: Drupal\farm_ui_views\Access\FarmLocationAssetViewsAccessCheck
     arguments: [ '@entity_type.manager', '@asset.location' ]

modules/core/ui/views/src/Access/FarmInventoryAssetViewsAccessCheck.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Drupal\farm_ui_views\Access;
+
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Routing\Access\AccessInterface;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Access\AccessResult;
+
+/**
+ * Checks access for displaying Views of inventory quantities for an asset.
+ */
+class FarmInventoryAssetViewsAccessCheck implements AccessInterface {
+
+  /**
+   * The asset storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $assetStorage;
+
+  /**
+   * FarmInventoryAssetViewsAccessCheck constructor.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager service.
+   */
+  public function __construct(EntityTypeManagerInterface $entity_type_manager) {
+    $this->assetStorage = $entity_type_manager->getStorage('asset');
+  }
+
+  /**
+   * A custom access check.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match.
+   */
+  public function access(RouteMatchInterface $route_match) {
+
+    // If there is no "asset" parameter, bail.
+    $asset_id = $route_match->getParameter('asset');
+    if (empty($asset_id)) {
+      return AccessResult::allowed();
+    }
+
+    // Allow access if the asset has an inventory.
+    /** @var \Drupal\asset\Entity\AssetInterface $asset */
+    $asset = $this->assetStorage->load($asset_id);
+    $access = AccessResult::allowedIf($asset->hasField('inventory') && !$asset->get('inventory')->isEmpty());
+
+    // Invalidate the access result when the asset is changed.
+    $access->addCacheTags($asset->getCacheTags());
+    return $access;
+  }
+
+}

modules/core/ui/views/src/Routing/RouteSubscriber.php

@@ -33,6 +33,12 @@ class RouteSubscriber extends RouteSubscriberBase {
     if ($route = $collection->get('view.farm_asset.page_location')) {
       $route->setRequirement('_location_assets_access', 'Drupal\farm_ui_views\Access\FarmLocationAssetViewsAccessCheck::access');
     }
+
+    // Add our _inventory_asset_access requirement to
+    // view.farm_inventory.page_asset.
+    if ($route = $collection->get('view.farm_inventory.page_asset')) {
+      $route->setRequirement('_asset_inventory_access', 'Drupal\farm_ui_views\Access\FarmInventoryAssetViewsAccessCheck::access');
+    }
   }
 
 }