Add sendNotificationMessage hook.

README.md

@@ -57,4 +57,34 @@ if (null !== $objNotificationCollection) {
         $objNotification->send($arrTokens, $strLanguage); // Language is optional
     }
 }
-```
+```
+
+## Hooks
+
+If you want to enrich each message being send by some meta data or want to disable some messages being sent, you can
+use the sendNotificationMessage hook:
+
+```php
+
+// config.php
+$GLOBALS['TL_HOOKS']['sendNotificationMessage'][] = array('MyHook', 'execute');
+
+// The hook
+class MyHook
+{
+    public function execute($objMessage, $arrTokens, $language, $objGatewayModel)
+    {
+         if (!$objMessage->regardUserSettings || !FE_USER_LOGGED_IN 
+            || $objMessage->getRelated('pid')->type !== 'custom_notification') {
+            return true;
+         }
+
+         $user = \MemberModel::findByPK($arrTokens['recipient']);     
+         if (!$user || !$user->disableEmailNotifications) {
+            return true;
+         }
+
+         return false;
+    }
+}
+```

library/NotificationCenter/Model/Message.php

@@ -34,13 +34,24 @@ public function send(array $arrTokens, $strLanguage = '')
             return false;
         }
 
-        if (null !== $objGatewayModel->getGateway()) {
-            return $objGatewayModel->getGateway()->send($this, $arrTokens, $strLanguage);
+        if (null === $objGatewayModel->getGateway()) {
+            \System::log(sprintf('Could not find gateway class for gateway ID "%s".', $objGatewayModel->id), __METHOD__, TL_ERROR);
+
+            return false;
         }
 
-        \System::log(sprintf('Could not find gateway class for gateway ID "%s".', $objGatewayModel->id), __METHOD__, TL_ERROR);
+        if (isset($GLOBALS['TL_HOOKS']['sendNotificationMessage']) && is_array($GLOBALS['TL_HOOKS']['sendNotificationMessage'])) {
+            foreach ($GLOBALS['TL_HOOKS']['sendNotificationMessage'] as $arrCallback) {
+                $arrCallback = array(new $arrCallback[0](), $arrCallback[1]);
+                $blnSuccess  = call_user_func($arrCallback, $this, $arrTokens, $strLanguage, $objGatewayModel);
+
+                if (!$blnSuccess) {
+                    return false;
+                }
+            }
+        }
 
-        return false;
+        return $objGatewayModel->getGateway()->send($this, $arrTokens, $strLanguage);
     }
 
     /**