Fix #19741: Added option to use a closure for $variations definition in yii\filters\PageCache

Author: nadar

framework/CHANGELOG.md

@@ -4,6 +4,7 @@ Yii Framework 2 Change Log
 2.0.48 under development
 ------------------------
 
+- Enh #19741: Added option to use a closure for `$variations` definition in `yii\filters\PageCache` (nadar)
 - Bug #15376: Added $userId for RBAC roles cache (manchenkoff)
 - Bug #18867: Fixed multiple issues with `yii\grid\CheckboxColumn`: "check all" checkbox not being checked on page load when all data row checkboxes are initially checked; clicking checkboxes triggered "change" event for other checkboxes that do not change their state; "check all" checkbox not being checked when disabled checkboxes are present and clicking last non-checked data row checkbox (PowerGamer1)
 - Bug #19635: PHP 8.2 compatibility fix for `yii\validators\DateValidator` (PowerGamer1)

framework/filters/PageCache.php

@@ -7,6 +7,7 @@
 
 namespace yii\filters;
 
+use Closure;
 use Yii;
 use yii\base\Action;
 use yii\base\ActionFilter;
@@ -98,7 +99,7 @@ class PageCache extends ActionFilter implements DynamicContentAwareInterface
      */
     public $dependency;
     /**
-     * @var string[]|string list of factors that would cause the variation of the content being cached.
+     * @var string[]|string|callable list of factors that would cause the variation of the content being cached.
      * Each factor is a string representing a variation (e.g. the language, a GET parameter).
      * The following variation setting will cause the content to be cached in different versions
      * according to the current application language:
@@ -108,6 +109,20 @@ class PageCache extends ActionFilter implements DynamicContentAwareInterface
      *     Yii::$app->language,
      * ]
      * ```
+     *
+     * Since version 2.0.48 you can provide an anonymous function to generate variations. This is especially helpful
+     * when you need to access the User component, which is resolved before the PageCache behavior:
+     *
+     * ```php
+     * 'variations' => function() {
+     *     return [
+     *         Yii::$app->language,
+     *         Yii::$app->user->id
+     *     ];
+     * }
+     * ```
+     *
+     * The callable should return an array.
      */
     public $variations;
     /**
@@ -318,7 +333,13 @@ protected function calculateCacheKey()
         if ($this->varyByRoute) {
             $key[] = Yii::$app->requestedRoute;
         }
-        return array_merge($key, (array)$this->variations);
+
+        if ($this->variations instanceof Closure || (is_array($this->variations) && is_callable($this->variations))) {
+            $variations = call_user_func($this->variations, $this);
+        } else {
+            $variations = $this->variations;
+        }
+        return array_merge($key, (array) $variations);
     }
 
     /**

tests/framework/filters/PageCacheTest.php

@@ -472,4 +472,24 @@ public function testCalculateCacheKey()
         $keys = $this->invokeMethod(new PageCache(), 'calculateCacheKey');
         $this->assertEquals(['yii\filters\PageCache', 'test'], $keys);
     }
+
+    public function testClosureVariations()
+    {
+        $keys = $this->invokeMethod(new PageCache([
+            'variations' => function() {
+                return [
+                    'foobar'
+                ];
+            }
+        ]), 'calculateCacheKey');
+        $this->assertEquals(['yii\filters\PageCache', 'test', 'foobar'], $keys);
+
+        // test type cast of string
+        $keys = $this->invokeMethod(new PageCache([
+            'variations' => function() {
+                return 'foobarstring';
+            }
+        ]), 'calculateCacheKey');
+        $this->assertEquals(['yii\filters\PageCache', 'test', 'foobarstring'], $keys);
+    }
 }