Cache expression

composer.json

@@ -14,7 +14,8 @@
     "ocramius/proxy-manager": "2.*",
     "psr/log": "1.*",
     "psr/cache": "1.0.*",
-    "doctrine/annotations": "1.3.*"
+    "doctrine/annotations": "1.3.*",
+    "symfony/expression-language": "3.*"
   },
   "suggest": {
     "symfony/cache": "3.*"

src/CacheBundle/Annotation/CacheExpression.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace CacheBundle\Annotation;
+
+use CacheBundle\Exception\CacheException;
+use Symfony\Component\Cache\Adapter\FilesystemAdapter;
+use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
+
+/**
+ * @Annotation
+ * @Target({"METHOD"})
+ */
+class CacheExpression extends Cache
+{
+    /**
+     * @var ExpressionLanguage
+     */
+    protected $expressionLanguage;
+
+    /**
+     * @var object
+     */
+    private $context;
+
+    /**
+     * @var bool
+     */
+    private $hasEvaluation = false;
+
+    /**
+     * @inheritDoc
+     */
+    public function getCache() : string
+    {
+        if (!$this->hasEvaluation) {
+            $this->cache = $this->getExpressionLanguage()->evaluate($this->cache, ['this' => $this->context]);
+            $this->hasEvaluation = true;
+        }
+
+        return $this->cache;
+    }
+
+    /**
+     * @param   object  $context
+     *
+     * @return  CacheExpression
+     */
+    public function setContext($context) : self
+    {
+        $this->context = $context;
+
+        return $this;
+    }
+
+    /**
+     * @return  ExpressionLanguage
+     *
+     * @throws  CacheException
+     */
+    private function getExpressionLanguage() : ExpressionLanguage
+    {
+        if (null === $this->expressionLanguage) {
+            if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
+                throw new CacheException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
+            }
+
+            $this->expressionLanguage = new ExpressionLanguage(new FilesystemAdapter('expr_cache'));
+        }
+
+        return $this->expressionLanguage;
+    }
+}

src/CacheBundle/ProxyManager/CacheableClassTrait.php

@@ -4,6 +4,7 @@
 
 
 use CacheBundle\Annotation\Cache;
+use CacheBundle\Annotation\CacheExpression;
 use Doctrine\Common\Annotations\AnnotationReader;
 use Doctrine\Common\Annotations\Reader;
 use Psr\Cache\CacheItemPoolInterface;
@@ -46,6 +47,9 @@ public function getCached(\ReflectionMethod $method, $params)
         /** @var Cache $annotation */
         $annotation = $this->readerForCacheMethod->getMethodAnnotation($method, Cache::class);
 
+        if ($annotation instanceof CacheExpression) {
+            $annotation->setContext($this);
+        }
         $cacheKey = $this->getCacheKey($method, $params, $annotation);
 
         $cacheItem = $this->cacheServiceForMethod->getItem($cacheKey);

tests/CacheWrapperTest.php

@@ -1,6 +1,9 @@
 <?php
 namespace CacheBundle\Tests;
 
+use CacheBundle\Annotation\CacheExpression;
+use CacheBundle\Tests\Helpers\CacheableClass;
+use Doctrine\Common\Annotations\AnnotationReader;
 use Doctrine\Common\Annotations\AnnotationRegistry;
 use Monolog\Handler\TestHandler;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
@@ -129,6 +132,20 @@ public function testAccessToProtectedMethod()
 
     }
 
+    public function testCachePrefixExpressions()
+    {
+        /** @var CacheableClass $object */
+        $object = $this->container->get('cache.testservice');
+        $objectReflectionClass = new \ReflectionClass($object);
+        $annotationReader = new AnnotationReader();
+        /** @var CacheExpression $cacheExpressionAnnotation */
+        $cacheExpressionAnnotation = $annotationReader->getMethodAnnotation(new \ReflectionMethod($objectReflectionClass->getParentClass()->getName(), 'getCachePrefixFromExpression'), CacheExpression::class);
+        $cacheExpressionAnnotation->setContext($object);
+
+        $this->assertContains($object->calculateCachePrefix(), $cacheExpressionAnnotation->getCache());
+        $this->assertEquals(0, strpos($cacheExpressionAnnotation->getCache(), $object->calculateCachePrefix()));
+    }
+
     /**
      * Get TestHandler object
      *

tests/Helpers/CacheableClass.php

@@ -1,10 +1,9 @@
 <?php
 
-
 namespace CacheBundle\Tests\Helpers;
 
-
 use CacheBundle\Annotation\Cache;
+use CacheBundle\Annotation\CacheExpression;
 
 class CacheableClass
 {
@@ -110,4 +109,22 @@ protected function protectedMethod()
     {
         return time();
     }
+
+    /**
+     * @CacheExpression(cache="this.calculateCachePrefix()")
+     *
+     * @return  int
+     */
+    public function getCachePrefixFromExpression() : int
+    {
+        return rand();
+    }
+
+    /**
+     * @return  string
+     */
+    public function calculateCachePrefix() : string
+    {
+        return 'xyz';
+    }
 }