add support for the class constant on objects

CHANGELOG

@@ -1,6 +1,7 @@
 # 3.3.9 (2022-XX-XX)
 
  * Fix custom escapers when using multiple Twig environments
+ * Add support for "constant('class', object)"
 
 # 3.3.8 (2022-02-04)
 

doc/functions/constant.rst

@@ -14,6 +14,12 @@ You can read constants from object instances as well:
 
     {{ constant('RSS', date) }}
 
+Retrieve the fully qualified class name of an object:
+
+.. code-block:: twig
+
+    {{ constant('class', date) }}
+
 Use the ``defined`` test to check if a constant is defined:
 
 .. code-block:: twig

src/Extension/CoreExtension.php

@@ -1359,6 +1359,10 @@ function twig_source(Environment $env, $name, $ignoreMissing = false)
 function twig_constant($constant, $object = null)
 {
     if (null !== $object) {
+        if ('class' === $constant) {
+            return \get_class($object);
+        }
+
         $constant = \get_class($object).'::'.$constant;
     }
 
@@ -1376,6 +1380,10 @@ function twig_constant($constant, $object = null)
 function twig_constant_is_defined($constant, $object = null)
 {
     if (null !== $object) {
+        if ('class' === $constant) {
+            return true;
+        }
+
         $constant = \get_class($object).'::'.$constant;
     }
 

tests/Fixtures/functions/constant.test

@@ -3,8 +3,10 @@
 --TEMPLATE--
 {{ constant('DATE_W3C') == expect ? 'true' : 'false' }}
 {{ constant('ARRAY_AS_PROPS', object) }}
+{{ constant('class', object) }}
 --DATA--
 return ['expect' => DATE_W3C, 'object' => new \ArrayObject(['hi'])]
 --EXPECT--
 true
 2
+ArrayObject