Set the template to deferred if the component is deferred and rendered for the first time

Author: jakubtobiasz

src/LiveComponent/src/EventListener/AddLiveAttributesSubscriber.php

@@ -73,6 +73,16 @@ public function onPreRender(PreRenderEvent $event): void
                     $originalAttributes['data-embedded-template-index'],
                 );
             }
+
+            $hasLiveId = isset($originalAttributes['data-live-id']);
+            $isDeferred = array_key_exists('defer', $originalAttributes);
+
+            // if the original attributes has a data-live-id, it means the component
+            // was already rendered
+            if (!$hasLiveId && $isDeferred) {
+                $attributes = $attributes->without('defer');
+                $event->setTemplate('@LiveComponent/deferred.html.twig');
+            }
         }
 
         // "key" is a special attribute: don't actually render it

src/LiveComponent/templates/deferred.html.twig

@@ -0,0 +1 @@
+<div {{ attributes }} data-action="live:connect->live#$render"></div>