Send element IDs with purge tags

src/HeaderEnum.php

@@ -6,6 +6,7 @@ enum HeaderEnum: string
 {
     case CACHE_TAG = 'Cache-Tag';
     case CACHE_PURGE_TAG = 'Cache-Purge-Tag';
+    case CACHE_PURGE_ELEMENT = 'Cache-Purge-Element';
     case CACHE_PURGE_PREFIX = 'Cache-Purge-Prefix';
     case CACHE_CONTROL = 'Cache-Control';
     case CDN_CACHE_CONTROL = 'CDN-Cache-Control';

src/Helper.php

@@ -30,6 +30,7 @@ public static function makeGatewayApiRequest(iterable $headers): ResponseInterfa
         }
 
         $headers = Collection::make($headers)
+            ->map(fn($value) => $value instanceof Collection ? $value->join(',') : (string) $value)
             ->put(HeaderEnum::REQUEST_TYPE->value, 'api');
 
         if (Module::getInstance()->getConfig()->getDevMode()) {

src/StaticCache.php

@@ -144,7 +144,11 @@ private function handleBeforeRenderPageTemplate(TemplateEvent $event): void
 
     private function handleInvalidateElementCaches(InvalidateElementCachesEvent $event): void
     {
-        $tags = Collection::make($event->tags)->map(fn(string $tag) => StaticCacheTag::create($tag)->minify(true));
+        $tags = Collection::make($event->tags)->map(
+            fn(string $tag) => StaticCacheTag::create($tag)
+                ->withElement($event->element)
+                ->minify(true)
+        );
 
         $skip = $tags->contains(function(StaticCacheTag $tag) {
             return preg_match('/element::craft\\\\elements\\\\\S+::(drafts|revisions)/', $tag->originalValue);
@@ -205,7 +209,8 @@ private function purgeElementUri(ElementInterface $element): void
             : Path::new($uri)->withLeadingSlash()->withoutTrailingSlash();
 
         $environmentId = Module::getInstance()->getConfig()->environmentId;
-        $this->tagsToPurge->prepend("$environmentId:$uri");
+        $tag = StaticCacheTag::create("$environmentId:$uri")->withElement($element);
+        $this->tagsToPurge->prepend($tag);
     }
 
     private function addCacheHeadersToWebResponse(): void
@@ -274,20 +279,21 @@ public function purgeTags(string|StaticCacheTag ...$tags): void
             'tags' => $tags,
         ]), __METHOD__);
 
+        $headers = Collection::make([
+            HeaderEnum::CACHE_PURGE_TAG->value => $tags->map(fn(StaticCacheTag $tag) => $tag->getValue())->unique()->filter(),
+            HeaderEnum::CACHE_PURGE_ELEMENT->value => $tags->map(fn(StaticCacheTag $tag) => $tag->element->id ?? null)->unique()->filter(),
+        ]);
+
         if ($isWebResponse) {
-            $tags->each(fn(StaticCacheTag $tag) => $response->getHeaders()->add(
-                HeaderEnum::CACHE_PURGE_TAG->value,
-                $tag->getValue(),
-            ));
+            $headers->each(function(Collection $values, string $name) use ($response) {
+                $values->each(fn($value) => $response->getHeaders()->add($name, $value));
+            });
 
             return;
         }
 
         // TODO: make sure we don't go over max header size
-        Helper::makeGatewayApiRequest([
-            // Mapping to string because: https://github.com/laravel/framework/pull/54630
-            HeaderEnum::CACHE_PURGE_TAG->value => $tags->map(fn(StaticCacheTag $tag) => (string) $tag)->implode(','),
-        ]);
+        Helper::makeGatewayApiRequest($headers);
     }
 
     public function purgeUrlPrefixes(string ...$urlPrefixes): void

src/StaticCacheTag.php

@@ -2,10 +2,13 @@
 
 namespace craft\cloud;
 
+use craft\base\ElementInterface;
+
 class StaticCacheTag implements \Stringable, \JsonSerializable
 {
     public readonly string $originalValue;
     private bool $minify = false;
+    public ?ElementInterface $element = null;
 
     public function __construct(
         private string $value,
@@ -18,11 +21,22 @@ public static function create(string $value): self
         return new self($value);
     }
 
+    public function withElement(?ElementInterface $element): self
+    {
+        $this->element = $element;
+
+        return $this;
+    }
+
     public function jsonSerialize(): false|string
     {
         return json_encode([
             'value' => $this->getValue(),
             'originalValue' => $this->originalValue,
+            'element' => $this->element?->getAttributes([
+                'id',
+                'url',
+            ]),
         ]);
     }