Offer a DI-type for other modules to change layout handles before using them

Author: jissereitsma

Layout/LayoutHandlerComposite.php

@@ -0,0 +1,42 @@
+<?php declare(strict_types=1);
+
+namespace Loki\Components\Layout;
+
+use Magento\Framework\View\LayoutInterface;
+
+class LayoutHandlerComposite
+{
+    public function __construct(
+        private readonly LayoutInterface $layout,
+        private readonly array $layoutHandlers = []
+    ) {
+    }
+
+    public function execute(array $handles): void
+    {
+        $originalHandles = $handles;
+        $handles = $this->getHandles($handles);
+        foreach ($handles as $handle) {
+            $this->layout->getUpdate()->addHandle($handle);
+        }
+
+        foreach (array_diff($originalHandles, $handles) as $handle) {
+            $this->layout->getUpdate()->removeHandle($handle);
+        }
+    }
+
+    public function getHandles(array $handles): array
+    {
+        foreach ($this->layoutHandlers as $layoutHandler) {
+            if (false === $layoutHandler instanceof LayoutHandlerInterface) {
+                continue;
+            }
+
+            $handles = $layoutHandler->get($handles);
+        }
+
+        $handles = array_unique($handles);
+
+        return $handles;
+    }
+}

Layout/LayoutHandlerInterface.php

@@ -0,0 +1,13 @@
+<?php
+declare(strict_types=1);
+
+namespace Loki\Components\Layout;
+
+interface LayoutHandlerInterface
+{
+    /**
+     * @param $handles string[]
+     * @return string[]
+     */
+    public function get(array $handles): array;
+}

Util/Controller/LayoutLoader.php

@@ -2,18 +2,21 @@
 
 namespace Loki\Components\Util\Controller;
 
+use Loki\Components\Layout\LayoutHandlerComposite;
 use Magento\Framework\View\LayoutInterface;
 use Magento\Framework\View\Result\PageFactory as ResultPageFactory;
 
 class LayoutLoader
 {
     public function __construct(
         private readonly ResultPageFactory $resultPageFactory,
+        private readonly LayoutHandlerComposite $layoutHandlerComposite
     ) {
     }
 
     public function load(array $handles = []): LayoutInterface
     {
+        $handles = $this->layoutHandlerComposite->getHandles($handles);
         $resultPage = $this->resultPageFactory->create();
 
         if ($handles !== []) {

Util/Controller/TargetRenderer.php

@@ -2,6 +2,7 @@
 
 namespace Loki\Components\Util\Controller;
 
+use Loki\Components\Layout\LayoutHandlerComposite;
 use Loki\Components\Util\IdConvertor;
 use Magento\Framework\Event\Manager as EventManager;
 use Magento\Framework\View\Element\AbstractBlock;
@@ -13,11 +14,16 @@ public function __construct(
         private readonly EventManager $eventManager,
         private readonly LayoutInterface $layout,
         private readonly IdConvertor $idConvertor,
+        private readonly LayoutHandlerComposite $layoutHandlerComposite,
+        private readonly LayoutLoader $layoutLoader
     ) {
     }
 
     public function render(LayoutInterface $layout, array $targetNames): array
     {
+        $handles = $this->layoutHandlerComposite->getHandles($layout->getUpdate()->getHandles());
+        $layout = $this->layoutLoader->load($handles);
+
         return $this->renderBlocks($layout, $this->getTargetBlockNames($targetNames));
     }