symfony · Engerim · Jun 11, 2017 · Jun 11, 2017 · Jun 11, 2017 · Jun 11, 2017
diff --git a/src/Symfony/Component/Validator/CHANGELOG.md b/src/Symfony/Component/Validator/CHANGELOG.md
@@ -11,6 +11,7 @@ CHANGELOG
    the `Url::CHECK_DNS_TYPE_*` constants values and will throw an exception in Symfony 4.0
  * added min/max amount of pixels check to `Image` constraint via `minPixels` and `maxPixels`
  * added a new "propertyPath" option to comparison constraints in order to get the value to compare from an array or object
+ * added a `dataPath` option to the `Expression` constraint to allow an other way to get `this` from the context
 
 3.3.0
 -----

diff --git a/src/Symfony/Component/Validator/Constraints/Expression.php b/src/Symfony/Component/Validator/Constraints/Expression.php
@@ -11,7 +11,9 @@
 
 namespace Symfony\Component\Validator\Constraints;
 
+use Symfony\Component\PropertyAccess\PropertyAccess;
 use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\Exception\RuntimeException;
 
 /**
  * @Annotation
@@ -30,6 +32,28 @@ class Expression extends Constraint
 
     public $message = 'This value is not valid.';
     public $expression;
+    protected $dataPath;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function __construct($options = null)
+    {
+        parent::__construct($options);
+
+        if ($this->dataPath && !class_exists(PropertyAccess::class)) {
+            throw new RuntimeException('Unable to use expressions with data path as the Symfony PropertyAccess component is not installed.');
+        }
+    }
+
+    public function __get($option)
+    {
+        if ('dataPath' === $option) {
+            return $this->dataPath;
+        }
+
+        return parent::__get($option);
+    }
 
     /**
      * {@inheritdoc}

diff --git a/src/Symfony/Component/Validator/Constraints/ExpressionValidator.php b/src/Symfony/Component/Validator/Constraints/ExpressionValidator.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Validator\Constraints;
 
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
+use Symfony\Component\PropertyAccess\PropertyAccess;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintValidator;
 use Symfony\Component\Validator\Exception\RuntimeException;
@@ -44,7 +45,12 @@ public function validate($value, Constraint $constraint)
 
         $variables = array();
         $variables['value'] = $value;
-        $variables['this'] = $this->context->getObject();
+
+        if ($constraint->dataPath) {
+            $variables['this'] = PropertyAccess::createPropertyAccessor()->getValue($this->context, $constraint->dataPath);
+        } else {
+            $variables['this'] = $this->context->getObject();
+        }
 
         if (!$this->getExpressionLanguage()->evaluate($constraint->expression, $variables)) {
             $this->context->buildViolation($constraint->message)

diff --git a/src/Symfony/Component/Validator/Tests/Constraints/ExpressionValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/ExpressionValidatorTest.php
@@ -235,4 +235,17 @@ public function testExpressionLanguageUsage()
 
         $this->assertTrue($used, 'Failed asserting that custom ExpressionLanguage instance is used.');
     }
+
+    public function testExpressionWithCustomDataPath()
+    {
+        $constraint = new Expression(array('expression' => 'value <= this["dateEnd"]', 'dataPath' => 'root[data]'));
+
+        $this->setRoot(array('data' => array('dateEnd' => '2011-06-07', 'dateStart' => '2011-06-05')));
+        $this->setPropertyPath('');
+        $this->setProperty(null, 'property');
+
+        $this->validator->validate('2011-06-05', $constraint);
+
+        $this->assertNoViolation();
+    }
 }