diff --git a/reference/constraints/Expression.rst b/reference/constraints/Expression.rst index 5db3373b55e..68526372837 100644 --- a/reference/constraints/Expression.rst +++ b/reference/constraints/Expression.rst @@ -217,6 +217,13 @@ more about the expression language syntax, see // ... } + .. caution:: + + In Symfony 2.4 and Symfony 2.5, if the property (e.g. ``isTechnicalPost``) + were ``null``, the expression would never be called and the value + would be seen as valid. To ensure that the value is not ``null``, + use the :doc:`NotNull constraint `. + For more information about the expression and what variables are available to you, see the :ref:`expression ` option details below.