From d7dce98aecc29480d2f629624b0fe981c3929e0c Mon Sep 17 00:00:00 2001
From: brandonkelly <brandon@pixelandtonic.com>
Date: Tue, 10 Dec 2024 11:53:26 -0800
Subject: [PATCH] Set no-cache headers on pages with image transform generation
 URLs

Resolves #16195
---
 CHANGELOG-WIP.md                         | 1 +
 src/imagetransforms/ImageTransformer.php | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/CHANGELOG-WIP.md b/CHANGELOG-WIP.md
index 56163672d01..27938a45128 100644
--- a/CHANGELOG-WIP.md
+++ b/CHANGELOG-WIP.md
@@ -8,4 +8,5 @@
 
 ## System
 - Database rows with foreign keys referencing nonexistent rows are now deleted via garbage collection.
+- Pages which contain image transform generation URLs now set no-cache headers. ([#16195](https://github.com/craftcms/cms/discussions/16195))
 - Updated Twig to 3.15. ([#16207](https://github.com/craftcms/cms/discussions/16207))
diff --git a/src/imagetransforms/ImageTransformer.php b/src/imagetransforms/ImageTransformer.php
index 74d32f870ea..ac2c746e94f 100644
--- a/src/imagetransforms/ImageTransformer.php
+++ b/src/imagetransforms/ImageTransformer.php
@@ -110,6 +110,9 @@ public function getTransformUrl(Asset $asset, ImageTransform $imageTransform, bo
                     'transformId' => $index->id,
                 ]), 2048);
 
+                // Prevent the page from being cached
+                Craft::$app->getResponse()->setNoCacheHeaders();
+
                 // Return the temporary transform URL
                 return UrlHelper::actionUrl('assets/generate-transform', [
                     'transformId' => $index->id,