added a note about how to check for dynamic attribute existence in the docs

diff --git a/doc/functions/attribute.rst b/doc/functions/attribute.rst
index 3051bda..ceba96b 100644 (file)
--- a/doc/functions/attribute.rst
+++ b/doc/functions/attribute.rst
@@ -4,7 +4,8 @@
 .. versionadded:: 1.2
     The ``attribute`` function was added in Twig 1.2.
 
-``attribute`` can be used to access a "dynamic" attribute of a variable:
+The ``attribute`` function can be used to access a "dynamic" attribute of a
+variable:
 
 .. code-block:: jinja
 
@@ -12,6 +13,13 @@
     {{ attribute(object, method, arguments) }}
     {{ attribute(array, item) }}
 
+In addition, the ``defined`` test can check for the existence of a dynamic
+attribute:
+
+.. code-block:: jinja
+
+    {{ attribute(object, method) is defined ? 'Method exists' : 'Method does not exist' }}
+
 .. note::
 
     The resolution algorithm is the same as the one used for the ``.``

diff --git a/test/Twig/Tests/Fixtures/functions/attribute.test b/test/Twig/Tests/Fixtures/functions/attribute.test
index 16ae1e8..472b74d 100644 (file)
--- a/test/Twig/Tests/Fixtures/functions/attribute.test
+++ b/test/Twig/Tests/Fixtures/functions/attribute.test
@@ -4,9 +4,13 @@
 {{ attribute(obj, method) }}
 {{ attribute(array, item) }}
 {{ attribute(obj, "bar", ["a", "b"]) }}
+{{ attribute(obj, method) is defined ? 'ok' : 'ko' }}
+{{ attribute(obj, nonmethod) is defined ? 'ok' : 'ko' }}
 --DATA--
-return array('obj' => new TwigTestFoo(), 'method' => 'foo', 'array' => array('foo' => 'bar'), 'item' => 'foo')
+return array('obj' => new TwigTestFoo(), 'method' => 'foo', 'array' => array('foo' => 'bar'), 'item' => 'foo', 'nonmethod' => 'xxx')
 --EXPECT--
 foo
 bar
 bar_a-b
+ok
+ko