From bdcb57ec2b22b335a526d5e303c4705cac6b3290 Mon Sep 17 00:00:00 2001
From: Guy Sartorelli <guy.sartorelli@silverstripe.com>
Date: Wed, 12 Apr 2023 17:29:59 +1200
Subject: [PATCH] NEW Add a cascading theme version of $resourceURL

---
 src/Core/Manifest/ModuleResourceLoader.php |  4 +--
 src/View/ThemeResourceLoader.php           | 29 +++++++++++++++++++---
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/src/Core/Manifest/ModuleResourceLoader.php b/src/Core/Manifest/ModuleResourceLoader.php
index 9dcb25de5..96cf80e2c 100644
--- a/src/Core/Manifest/ModuleResourceLoader.php
+++ b/src/Core/Manifest/ModuleResourceLoader.php
@@ -15,7 +15,7 @@ class ModuleResourceLoader implements TemplateGlobalProvider
     use Injectable;
 
     /**
-     * Convert a file of the form "vendor/package:resource" into a BASE_PATH-relative file
+     * Convert a file of the form "vendor/package:resource" into a BASE_PATH-relative file or folder
      * For other files, return original value
      *
      * @param string $resource
@@ -91,7 +91,7 @@ class ModuleResourceLoader implements TemplateGlobalProvider
      * Returns the original resource otherwise.
      *
      * @param string $resource
-     * @return ModuleResource|string The resource, or input string if not a module resource
+     * @return ModuleResource|string The resource (or directory), or input string if not a module resource
      */
     public function resolveResource($resource)
     {
diff --git a/src/View/ThemeResourceLoader.php b/src/View/ThemeResourceLoader.php
index e6f3d9b7e..7967c22bd 100644
--- a/src/View/ThemeResourceLoader.php
+++ b/src/View/ThemeResourceLoader.php
@@ -7,12 +7,13 @@ use Psr\SimpleCache\CacheInterface;
 use SilverStripe\Core\Flushable;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Core\Manifest\ModuleLoader;
+use SilverStripe\Core\Manifest\ModuleResourceLoader;
 use SilverStripe\Core\Path;
 
 /**
  * Handles finding templates from a stack of template manifest objects.
  */
-class ThemeResourceLoader implements Flushable
+class ThemeResourceLoader implements Flushable, TemplateGlobalProvider
 {
 
     /**
@@ -308,9 +309,9 @@ class ThemeResourceLoader implements Flushable
     }
 
     /**
-     * Resolve a themed resource
+     * Resolve a themed resource or directory
      *
-     * A themed resource and be any file that resides in a theme folder.
+     * A themed resource can be any file that resides in a theme folder.
      *
      * @param string $resource A file path relative to the root folder of a theme
      * @param array $themes An order listed of themes to search, Defaults to {@see SSViewer::get_themes()}
@@ -336,6 +337,28 @@ class ThemeResourceLoader implements Flushable
         return null;
     }
 
+    /**
+     * Return the URL for a given themed resource or directory within the project.
+     *
+     * A themed resource can be any file that resides in a theme folder.
+     */
+    public static function themedResourceURL(string $resource): ?string
+    {
+        $filePath = static::inst()->findThemedResource($resource);
+        if (!$filePath) {
+            return '';
+        }
+
+        return ModuleResourceLoader::singleton()->resolveURL($filePath);
+    }
+
+    public static function get_template_global_variables()
+    {
+        return [
+            'themedResourceURL',
+        ];
+    }
+
     /**
      * Resolve all themes to the list of root folders relative to site root
      *