Added language package

The package contains a local negotiator,
some base classes with a i18n switch adapter
and a library for session handling support.

This packages allows you to implement simply
i18n aware content types and configure the 
server (negotiator) for handling language 
policies. Such a policy could be, that the server 
will lookup for a fix language or language settings
set on a session or the setting from the browser.

See for more information inthe different README.txt 
files or in the included tests

src/z3c/language/__init__.py

@@ -0,0 +1,17 @@
+##############################################################################
+#
+# Copyright (c) 2005 Zope Foundation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+"""
+$Id$
+"""
+

src/z3c/language/negotiator/README.txt

@@ -0,0 +1,77 @@
+==========
+Negotiator
+==========
+
+Setup testbrowser for Negotiator functional tests.
+
+  >>> from zope.testbrowser.testing import Browser
+  >>> browser = Browser()
+  >>> browser.addHeader('Authorization', 'Basic mgr:mgrpw')
+  >>> browser.handleErrors = False
+
+Start Zope3 an go to the root.
+
+  >>> browser.open('http://localhost/@@contents.html')
+  >>> browser.url
+  'http://localhost/@@contents.html'
+
+Add a negotiator.
+
+  >>> browser.open('http://localhost/++etc++site/default/@@contents.html?type_name=BrowserAdd__z3c.language.negotiator.app.Negotiator')
+  >>> browser.url
+  'http://localhost/++etc++site/default/@@contents.html?type_name=BrowserAdd__z3c.language.negotiator.app.Negotiator'
+  >>> browser.getControl(name='new_value').value = ''
+  >>> browser.getControl('Apply').click()
+  >>> browser.url
+  'http://localhost/++etc++site/default/Negotiator/@@registration.html'
+
+And register the added negotiator utility.
+
+  >>> browser.handleErrors = False
+  >>> "This object isn't yet registered." in browser.contents
+  True
+  >>> browser.getLink('Registration').click()
+  >>> browser.getControl('Register this object').click()
+  >>> browser.url
+  'http://localhost/++etc++site/default/Negotiator/@@addRegistration.html'
+  >>> browser.getControl(
+  ...     'Provided interface').value = ['zope.i18n.interfaces.INegotiator']
+  >>> browser.getControl('Register As').value = ''
+  >>> browser.getControl('Comment').value = 'A local negotiator'
+  >>> browser.getControl('Register', index=1).click()
+  >>> browser.url
+  'http://localhost/++etc++site/default/Negotiator/@@registration.html'
+
+Now we see the edit form of the added and registred negotiator instance called
+Negotiator. Set the language lookup policy to 'server'.
+
+  >>> browser.open('http://localhost/++etc++site/default/Negotiator/'
+  ...    '@@edit.html')
+  >>> browser.getControl(name='field.policy').value = ['server']
+
+and set a default server language called 'de'.
+
+  >>> browser.getControl(name='field.serverLanguage').value = 'de'
+
+and save this part.
+
+  >>> browser.getControl(name='UPDATE_SUBMIT').click()
+
+Now we add a session language via the used sequence list widget.
+
+  >>> browser.getControl(name='field.sessionLanguages.add').click()
+  >>> browser.getControl(name='field.sessionLanguages.0.').value = 'fr'
+
+And we also add a offered language.
+
+  >>> browser.getControl(name='field.offeredLanguages.add').click()
+  >>> browser.getControl(name='field.offeredLanguages.0.').value = 'de'
+
+And as last, we save the changes.
+
+  >>> browser.getControl(name='UPDATE_SUBMIT').click()
+
+Now check if the set language is german. See the label at the submit button.
+
+  >>> browser.getControl(name='UPDATE_SUBMIT').value
+  'Abschicken'

src/z3c/language/negotiator/SETUP.cfg

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+<data-files zopeskel/etc/package-includes>
+  z3c.language.negotiator-*.zcml
+</data-files>

src/z3c/language/negotiator/__init__.py

@@ -0,0 +1,21 @@
+##############################################################################
+#
+# Copyright (c) 2005 Zope Foundation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+"""
+$Id$
+"""
+
+__docformat__ = 'restructuredtext'
+
+from z3c.language.negotiator.interfaces import *

src/z3c/language/negotiator/app.py

@@ -0,0 +1,139 @@
+##############################################################################
+#
+# Copyright (c) 2005 Zope Foundation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+"""
+$Id$
+"""
+__docformat__ = 'restructuredtext'
+
+from persistent import Persistent
+from zope.interface import implements
+
+from zope.i18n.interfaces import IUserPreferredLanguages
+from zope.i18n.interfaces import INegotiator
+from zope.i18n.negotiator import negotiator
+
+from zope.app.container.contained import Contained
+
+from z3c.language.session.interfaces import ILanguageSession
+
+from z3c.language.negotiator.interfaces import INegotiatorManager
+from z3c.language.negotiator.interfaces import language_policies
+
+
+
+class Negotiator(Persistent, Contained):
+    """Loacal negotiator implementation.
+
+    The negotiator let you change the policy, which is a alias
+    for the lookup mechanism. 
+
+    'server' -- The server defines the language
+
+    'session' -- The session defines the language (usefull for testing)
+
+    'browser' -- The browser defines the language (usefull for testing)
+
+    'browser --> session --> server' -- Left criteria first
+
+    'browser --> server' -- Left criteria first
+
+    'session --> browser --> server' -- Left criteria first (default use case)
+
+    'session --> server' -- Left criteria first
+
+    The 'server' criteria is used as a fallback criteria in most use cases.
+
+    """
+
+    implements(INegotiator, INegotiatorManager)
+
+    def __init__(self):
+        self._policy = 'session --> browser --> server'
+        self._serverLanguage = None
+        self._sessionLanguages = []
+        self._offeredLanguages = []
+
+    def _getLanguagePolicy(self):
+        """Returns the language policy."""
+        return self._policy
+
+    def _setLanguagePolicy(self, policy):
+        """Set the language policy."""
+        if policy not in language_policies:
+            policies = str(language_policies)
+            msg = "Only %s are valide policy names." % policies
+            raise ValueError(msg, policy)
+        self._policy = policy
+
+    policy = property(_getLanguagePolicy, _setLanguagePolicy)
+
+    def _getServerLanguage(self):
+        """Returns the language for server policy."""
+        return self._serverLanguage
+
+    def _setServerLanguage(self, language):
+        """Set the language for server policy."""
+        self._serverLanguage = language
+
+    serverLanguage = property(_getServerLanguage, _setServerLanguage)
+
+    def _getSessionLanguages(self):
+        """Returns the language for server policy."""
+        return self._sessionLanguages
+
+    def _setSessionLanguages(self, languages):
+        """Set the language for server policy."""
+        self._sessionLanguages = languages
+
+    sessionLanguages = property(_getSessionLanguages, _setSessionLanguages)
+
+    # TODO: 
+    # perhaps we can make a relation to the translation domains
+    # and dymanicly find out what language we support in the domains.
+    def _getOfferedLanguages(self):
+        """Returns the language for server policy."""
+        return self._offeredLanguages
+
+    def _setOfferedLanguages(self, languages):
+        """Set the language for server policy."""
+        self._offeredLanguages = languages
+
+    offeredLanguages = property(_getOfferedLanguages, _setOfferedLanguages)
+
+    def getLanguage(self, languages, request):
+        """Returns the language dependent on the policy."""
+        policyList = self._policy.split(' --> ')
+
+        for policy in policyList:
+
+            # the server is handling the language
+            if policy == 'server':
+                if self.serverLanguage:
+                    return self.serverLanguage
+
+            # the language is handled by a session 
+            elif policy == 'session':
+                session = ILanguageSession(request)
+                lang = session.getLanguage()
+                if lang != None:
+                    return lang
+
+            # the language is handled by the browsers language settings
+            elif policy == 'browser':
+                lang = negotiator.getLanguage(languages, request)
+                if lang != None:
+                    return lang
+
+        return None

src/z3c/language/negotiator/browser/__init__.py

@@ -0,0 +1,17 @@
+##############################################################################
+#
+# Copyright (c) 2005 Zope Foundation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+"""
+$Id$
+"""

src/z3c/language/negotiator/browser/configure.zcml

@@ -0,0 +1,39 @@
+<configure
+    xmlns:zope="http://namespaces.zope.org/zope"
+    xmlns="http://namespaces.zope.org/browser"
+    i18n_domain="z3c.language">
+
+  <!-- local negotiator -->
+  <addMenuItem
+      title="Negotiator"
+      description="Negotiator returns the i18n language for translation."
+      class="z3c.language.negotiator.app.Negotiator"
+      permission="zope.ManageSite"
+      />
+
+  <editform
+      name="edit.html"
+      label="Negotiator for i18n language lookup."
+      schema="..INegotiatorManager"
+      menu="zmi_views" title="Edit"
+      permission="zope.ManageContent"
+      />
+
+  <!-- negotiator views -->
+  <page
+      for="*"
+      name="offered_languages"
+      permission="zope.Public"
+      class=".views.NegotiatorView"
+      attribute="getOfferedLanguages"
+      />
+
+  <page
+      for="*"
+      name="hasOfferedLanguages"
+      permission="zope.Public"
+      class=".views.NegotiatorView"
+      attribute="hasOfferedLanguages"
+      />
+
+</configure>

src/z3c/language/negotiator/browser/views.py

@@ -0,0 +1,59 @@
+##############################################################################
+#
+# Copyright (c) 2005 Zope Foundation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+"""
+$Id$
+"""
+__docformat__ = 'restructuredtext'
+
+from zope.interface import implements
+from zope.i18n.interfaces import INegotiator
+from zope.publisher.browser import BrowserView
+
+from zope.app.zapi import getUtility
+
+from z3c.language.negotiator import IOfferedLanguages
+
+
+
+class NegotiatorView(BrowserView):
+
+    implements(IOfferedLanguages)
+
+    def getOfferedLanguages(self):
+        """View for listing  available (offered) languages."""
+
+        negotiator = getUtility(INegotiator, '', self.context)
+
+        try:
+            offeredLanguages = negotiator.offeredLanguages
+        except:
+            # we don't have a Negotiator instance
+            # we got the global zope.i18n Negotiator
+            offeredLanguages = []
+
+        return offeredLanguages
+
+    def hasOfferedLanguages(self):
+        """View for to check if we have i18n session support."""
+
+        negotiator = getUtility(INegotiator, '', self.context)
+
+        try:
+            offeredLanguages = negotiator.offeredLanguages
+            return True
+        except:
+            # we don't have a Negotiator instance
+            # we got the global zope.i18n Negotiator
+            return False