Metadata-Version: 2.1
Name: zope.app.session
Version: 5.0
Summary: Zope session
Home-page: https://github.com/zopefoundation/zope.app.session
Author: Zope Corporation and Contributors
Author-email: zope-dev@zope.dev
License: ZPL 2.1
Keywords: zope3 session
Classifier: Development Status :: 5 - Production/Stable
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Zope Public License
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Topic :: Internet :: WWW/HTTP
Classifier: Framework :: Zope :: 3
Requires-Python: >=3.7
Provides-Extra: test

This package provides session support.


==============================
 Zope3 Session Implementation
==============================

.. note:: All interfaces and implementations provided by this package
          have been migrated to ``zope.session``. This package now
          merely provides ZMI menu configuration.

Overview
========

.. CAUTION::
    Session data is maintained on the server. This gives a security
    advantage in that we can assume that a client has not tampered with
    the data.  However, this can have major implications for scalability
    as modifying session data too frequently can put a significant load
    on servers and in extreme situations render your site unusable.
    Developers should keep this in mind when writing code or risk
    problems when their application is run in a production environment.

    Applications requiring write-intensive session implementations (such
    as page counters) should consider using cookies or specialized
    session implementations.

Sessions allow us to fake state over a stateless protocol - HTTP.
We do this by having a unique identifier stored across multiple
HTTP requests, be it a cookie or some id mangled into the URL.


The ``IClientIdManager`` Utility provides this unique id. It is
responsible for propagating this id so that future requests from the
client get the same id (eg. by setting an HTTP cookie). (Note that
this, and all interfaces, are imported from this package for
demonstration purposes only. They have been moved to
``zope.session.interfaces``) This utility is used when we adapt the
request to the unique client id:

    >>> from zope.app.session.interfaces import IClientId
    >>> IClientId
    <InterfaceClass zope.session.interfaces.IClientId>
    >>> client_id = IClientId(request)

The ``ISession`` adapter gives us a mapping that can be used to store
and retrieve session data. A unique key (the package id) is used
to avoid namespace clashes:

    >>> from zope.app.session.interfaces import ISession
    >>> pkg_id = 'products.foo'
    >>> session = ISession(request)[pkg_id]
    >>> session['color'] = 'red'

    >>> session2 = ISession(request)['products.bar']
    >>> session2['color'] = 'blue'

    >>> session['color']
    'red'
    >>> session2['color']
    'blue'


Data Storage
============

The actual data is stored in an ``ISessionDataContainer`` utility.
``ISession`` chooses which ``ISessionDataContainer`` should be used by
looking up as a named utility using the package id. This allows
the site administrator to configure where the session data is actually
stored by adding a registration for desired ``ISessionDataContainer``
with the correct name.

    >>> from zope.app.session.interfaces import ISessionDataContainer
    >>> from zope.component import getUtility
    >>> sdc = getUtility(ISessionDataContainer, pkg_id)
    >>> sdc[client_id][pkg_id] is session
    True
    >>> sdc[client_id][pkg_id]['color']
    'red'

If no ``ISessionDataContainer`` utility can be located by name using the
package id, then the unnamed ``ISessionDataContainer`` utility is used as
a fallback. An unnamed ``ISessionDataContainer`` is automatically created
for you, which may replaced with a different implementation if desired.

    >>> ISession(request)['unknown'] \
    ...     is getUtility(ISessionDataContainer)[client_id]['unknown']
    True

The ``ISessionDataContainer`` contains ``ISessionData`` objects, and
``ISessionData`` objects in turn contain ``ISessionPkgData`` objects. You
should never need to know this unless you are writing administrative
views for the session machinery.

    >>> from zope.app.session.interfaces import ISessionData, ISessionPkgData
    >>> ISessionData.providedBy(sdc[client_id])
    True
    >>> ISessionPkgData.providedBy(sdc[client_id][pkg_id])
    True

The ``ISessionDataContainer`` is responsible for expiring session data.
The expiry time can be configured by settings its ``timeout`` attribute.

    >>> sdc.timeout = 1200 # 1200 seconds or 20 minutes


Restrictions
============

Data stored in the session must be persistent or picklable.

    >>> class NoPickle(object):
    ...     def __getstate__(self):
    ...         raise TypeError("Cannot serialize")
    >>> session['oops'] = NoPickle()
    >>> import transaction
    >>> transaction.commit()
    Traceback (most recent call last):
    ...
    TypeError: Cannot serialize

..
 Clean up:

    >>> transaction.abort()


Page Templates
==============

    Session data may be accessed in page template documents using
    TALES::

        <span tal:content="request/session:products.foo/color | default">
            green
        </span>

    or::

        <div tal:define="session request/session:products.foo">
            <script type="text/server-python">
                try:
                    session['count'] += 1
                except KeyError:
                    session['count'] = 1
            </script>

            <span tal:content="session/count" />
        </div>


=========
 CHANGES
=========

5.0 (2023-02-10)
================

- Drop support for Python 2.7, 3.5, 3.6.

- Add support for Python 3.8, 3.9, 3.10, 3.11.


4.1.0 (2018-10-22)
==================

- Add support for Python 3.7.


4.0.0 (2017-05-29)
==================

- Add support for Python 3.4, 3.5, 3.6 and PyPy.

- Remove dependency on ``ZODB3`` and other packages that are not used
  by this package, leaving behind only ``zope.session``. Packages that
  are used during testing are now test dependencies.


3.6.2 (2010-09-01)
==================

- Remove undeclared dependency on ``zope.deferredimport``.

3.6.1 (2010-02-06)
==================

- Include meta.zcml from zope.securitypolicy

3.6.0 (2009-02-01)
==================

- Use ``zope.site`` instead of ``zope.app.folder`` in tests.

3.5.2 (2009-01-27)
==================

- Fixed tearDown-Error in tests.

3.5.1 (2007-10-31)
==================

- Resolve ``ZopeSecurityPolicy`` deprecation warning.

3.5.0 (2007-09-27)
==================

* A release to override an untagged, unreasoned dev release in
  ``download.zope.org/distribution``.


3.4.3 (2007-09-27)
==================

* Fix package meta-data.

3.4.2 (2007-09-24)
==================

- rebumped to replace faulty egg

- added missing dependecy to ``zope.session``


3.4.1 (2007-09-24)
==================

- Added missing files to egg distribution


3.4.0 (2007-09-24)
==================

- Initial documented release
