minor #14845 [HttpFoundation] deprecate the NamespacedAttributeBag class (xabbuh)

This PR was merged into the 5.3-dev branch.

Discussion
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[HttpFoundation] deprecate the NamespacedAttributeBag class

fixes #14842

Commits
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9df0164 deprecate the NamespacedAttributeBag class

Author: javiereguiluz

components/http_foundation/sessions.rst

@@ -169,6 +169,11 @@ and "Remember Me" login settings or other user based state information.
 :class:`Symfony\\Component\\HttpFoundation\\Session\\Attribute\\NamespacedAttributeBag`
     This implementation allows for attributes to be stored in a structured namespace.
 
+    .. deprecated:: 5.3
+
+        The ``NamespacedAttributeBag`` class is deprecated since Symfony 5.3.
+        If you need this feature, you will have to implement the class yourself.
+
 :class:`Symfony\\Component\\HttpFoundation\\Session\\Attribute\\AttributeBagInterface`
 has the API
 
@@ -237,6 +242,11 @@ So any processing of this might quickly get ugly, even adding a token to the arr
     $tokens['c'] = $value;
     $session->set('tokens', $tokens);
 
+.. deprecated:: 5.3
+
+    The ``NamespacedAttributeBag`` class is deprecated since Symfony 5.3.
+    If you need this feature, you will have to implement the class yourself.
+
 With structured namespacing, the key can be translated to the array
 structure like this using a namespace character (which defaults to ``/``)::
 

session.rst

@@ -167,6 +167,11 @@ By default, session attributes are key-value pairs managed with the
 :class:`Symfony\\Component\\HttpFoundation\\Session\\Attribute\\AttributeBag`
 class.
 
+.. deprecated:: 5.3
+
+    The ``NamespacedAttributeBag`` class is deprecated since Symfony 5.3.
+    If you need this feature, you will have to implement the class yourself.
+
 If your application needs are complex, you may prefer to use
 :ref:`namespaced session attributes <namespaced-attributes>` which are managed with the
 :class:`Symfony\\Component\\HttpFoundation\\Session\\Attribute\\NamespacedAttributeBag`