Feb 5, 2015 · Dec 16, 2014 · Dec 17, 2014 · Dec 22, 2014 · Feb 5, 2015 · Jan 23, 2015
diff --git a/cookbook/map.rst.inc b/cookbook/map.rst.inc
  * :doc:`/cookbook/session/sessions_directory`
  * :doc:`/cookbook/session/php_bridge`
  * (configuration) :doc:`/cookbook/configuration/pdo_session_storage`
  * :doc:`/cookbook/session/avoid_session_start`

 * **symfony1**

diff --git a/cookbook/session/avoid_session_start.rst b/cookbook/session/avoid_session_start.rst
 .. index::
    single: Sessions, cookies

 Avoid Starting Sessions for Anonymous Users
 ===========================================

 Sessions are automatically started whenever you read, write or even check for the
 existence of data in the session. This means that if you need to avoid creating
 a session cookie for some users, it can be difficult: you must *completely* avoid
 accessing the session.

 For example, one common problem in this situation involves checking for flash
 messages, which are stored in the session. The following code would guarantee
 that a session is *always* started:

 .. code-block:: html+jinja

    {% for flashMessage in app.session.flashbag.get('notice') %}
        <div class="flash-notice">
            {{ flashMessage }}
        </div>
    {% endfor %}

 Even if the user is not logged in and even if you haven't created any flash message,
 just calling the ``get()`` (or even ``has()``) method of the ``flashbag`` will
 start a session. This may hurt your application performance because all users will
 receive a session cookie. To avoid this behavior, add a check before trying to
 access the flash messages:

 .. code-block:: html+jinja

    {% if app.request.hasPreviousSession %}
        {% for flashMessage in app.session.flashbag.get('notice') %}
            <div class="flash-notice">
                {{ flashMessage }}
            </div>
        {% endfor %}
    {% endif %}
diff --git a/cookbook/session/index.rst b/cookbook/session/index.rst
    proxy_examples
    locale_sticky_session
    sessions_directory
    php_bridge
    php_bridge
    avoid_session_start
Original file line number	Diff line number	Diff line change
Expand Up		@@ -166,6 +166,7 @@
		* :doc:`/cookbook/session/sessions_directory`
		* :doc:`/cookbook/session/php_bridge`
		* (configuration) :doc:`/cookbook/configuration/pdo_session_storage`
		* :doc:`/cookbook/session/avoid_session_start`

		* symfony1

Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,38 @@
		.. index::
		single: Sessions, cookies

		Avoid Starting Sessions for Anonymous Users
		===========================================

		Sessions are automatically started whenever you read, write or even check for the
		existence of data in the session. This means that if you need to avoid creating
		a session cookie for some users, it can be difficult: you must completely avoid
		accessing the session.

		For example, one common problem in this situation involves checking for flash
		messages, which are stored in the session. The following code would guarantee
		that a session is always started:

		.. code-block:: html+jinja

		{% for flashMessage in app.session.flashbag.get('notice') %}
		<div class="flash-notice">
		{{ flashMessage }}
		</div>
		{% endfor %}

		Even if the user is not logged in and even if you haven't created any flash message,
		just calling the ``get()`` (or even ``has()``) method of the ``flashbag`` will
		start a session. This may hurt your application performance because all users will
		receive a session cookie. To avoid this behavior, add a check before trying to
		access the flash messages:

		.. code-block:: html+jinja

		{% if app.request.hasPreviousSession %}
		{% for flashMessage in app.session.flashbag.get('notice') %}
Copy link Member weaverryanJan 23, 2015 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Ok, so I don't think this is right - it's a confusing thing: A)`Session::isStarted()` checks if the session has been started onthis request or not. This isnot what we want B)`Request::hasPreviousSession()` checks if the user has a session cookie - i.e. if a session was created on a previous request. This is what wedo want. There's a huge confusion over this - I was just readingsymfony/symfony#6036 andsymfony/symfony#6388 about this - the functionality for this is not right in the core, which is why this is so difficult.
		<div class="flash-notice">
		{{ flashMessage }}
		</div>
		{% endfor %}
		{% endif %}
Original file line number	Diff line number	Diff line change
Expand Up		@@ -7,4 +7,5 @@ Sessions
		proxy_examples
		locale_sticky_session
		sessions_directory
		php_bridge
		php_bridge
		avoid_session_start