do not fail when expression language is not needed

Author: dbu

CHANGELOG.md

@@ -1,6 +1,14 @@
 Changelog
 =========
 
+2.10.3
+------
+
+### Fixed
+
+* Do not error in `InvalidationListener` nor `TagListener` when `symfony/expression-language` is missing but no expression is used.
+* Properly report missing `symfony/expression-language` when an expression is used in response configuration.
+
 2.10.2
 ------
 

src/DependencyInjection/Configuration.php

@@ -240,6 +240,10 @@ private function addCacheableResponseSection(ArrayNodeDefinition $rootNode)
                                 return !empty($v['additional_status']) && !empty($v['expression']);
                             })
                             ->thenInvalid('You may not set both additional_status and expression.')
+                            ->ifTrue(function ($v) {
+                                return !empty($v['expression']) && !class_exists(ExpressionLanguage::class);
+                            })
+                            ->thenInvalid('Configured a response.expression but ExpressionLanguage is not available')
                         ->end()
                     ->end()
                 ->end()

src/EventListener/InvalidationListener.php

@@ -80,7 +80,7 @@ public function __construct(
     ) {
         $this->cacheManager = $cacheManager;
         $this->urlGenerator = $urlGenerator;
-        $this->expressionLanguage = $expressionLanguage ?: new ExpressionLanguage();
+        $this->expressionLanguage = $expressionLanguage;
         $this->mustInvalidateRule = $mustInvalidateRule;
     }
 
@@ -217,7 +217,7 @@ private function invalidateRoutes(array $routes, Request $request)
                 // Iterate over route params and try to evaluate their values
                 foreach ($route->getParams() as $key => $value) {
                     if (is_array($value)) {
-                        $value = $this->expressionLanguage->evaluate($value['expression'], $values);
+                        $value = $this->getExpressionLanguage()->evaluate($value['expression'], $values);
                     }
 
                     $params[$key] = $value;
@@ -227,4 +227,17 @@ private function invalidateRoutes(array $routes, Request $request)
             $this->cacheManager->invalidateRoute($route->getName(), $params);
         }
     }
+
+    private function getExpressionLanguage(): ExpressionLanguage
+    {
+        if (!$this->expressionLanguage) {
+            // the expression comes from controller annotations, we can't detect whether they use expressions while building the configuration
+            if (!class_exists(ExpressionLanguage::class)) {
+                throw new \RuntimeException('Invalidation rules with expressions require '.ExpressionLanguage::class.' to be available.');
+            }
+            $this->expressionLanguage = new ExpressionLanguage();
+        }
+
+        return $this->expressionLanguage;
+    }
 }

src/EventListener/TagListener.php

@@ -48,7 +48,7 @@ class TagListener extends AbstractRuleListener implements EventSubscriberInterfa
     private $symfonyResponseTagger;
 
     /**
-     * @var ExpressionLanguage
+     * @var ExpressionLanguage|null
      */
     private $expressionLanguage;
 
@@ -76,7 +76,7 @@ public function __construct(
         $this->symfonyResponseTagger = $tagHandler;
         $this->cacheableRule = $cacheableRule;
         $this->mustInvalidateRule = $mustInvalidateRule;
-        $this->expressionLanguage = $expressionLanguage ?: new ExpressionLanguage();
+        $this->expressionLanguage = $expressionLanguage;
     }
 
     /**
@@ -173,6 +173,19 @@ private function evaluateTag($expression, Request $request)
         // if there is an attribute called "request", it needs to be accessed through the request.
         $values['request'] = $request;
 
-        return $this->expressionLanguage->evaluate($expression, $values);
+        return $this->getExpressionLanguage()->evaluate($expression, $values);
+    }
+
+    private function getExpressionLanguage(): ExpressionLanguage
+    {
+        if (!$this->expressionLanguage) {
+            // the expression comes from controller annotations, we can't detect whether they use expressions while building the configuration
+            if (!class_exists(ExpressionLanguage::class)) {
+                throw new \RuntimeException('Using the tag annotation requires the '.ExpressionLanguage::class.' to be available.');
+            }
+            $this->expressionLanguage = new ExpressionLanguage();
+        }
+
+        return $this->expressionLanguage;
     }
 }