Add entity-types-php mixin

mixin/entity-types-php@1/mixin.php

@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * Auto-register entity declarations from `xml/schema/...*.entityType.php`.
+ *
+ * @mixinName entity-types-php
+ * @mixinVersion 1.0.0
+ * @since 5.57
+ *
+ * @param CRM_Extension_MixInfo $mixInfo
+ *   On newer deployments, this will be an instance of MixInfo. On older deployments, Civix may polyfill with a work-a-like.
+ * @param \CRM_Extension_BootCache $bootCache
+ *   On newer deployments, this will be an instance of MixInfo. On older deployments, Civix may polyfill with a work-a-like.
+ */
+return function ($mixInfo, $bootCache) {
+
+  /**
+   * @param \Civi\Core\Event\GenericHookEvent $e
+   * @see CRM_Utils_Hook::entityTypes()
+   */
+  Civi::dispatcher()->addListener('hook_civicrm_entityTypes', function ($e) use ($mixInfo) {
+    // When deactivating on a polyfill/pre-mixin system, listeners may not cleanup automatically.
+    if (!$mixInfo->isActive() || !is_dir($mixInfo->getPath('xml/schema/CRM'))) {
+      return;
+    }
+
+    $files = (array) glob($mixInfo->getPath('xml/schema/CRM/*/*.entityType.php'));
+    foreach ($files as $file) {
+      $entity = include $file;
+      $e->entityTypes[$entity['class']] = $entity;
+    }
+  });
+
+};