copy to keep the histroy

src/grokcore/traverser/util.py

@@ -0,0 +1,83 @@
+##############################################################################
+#
+# Copyright (c) 2006-2007 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.
+#
+##############################################################################
+"""Grok utility functions.
+"""
+import grok
+import grokcore.site.interfaces
+import zope.location.location
+
+from zope import interface
+from zope.schema.interfaces import WrongType
+from grokcore.view.util import url
+from grokcore.site.util import getApplication
+
+
+def safely_locate_maybe(obj, parent, name):
+    """Set an object's __parent__ (and __name__) if the object's
+    __parent__ attribute doesn't exist yet or is None.
+
+    If the object provides ILocation, __parent__ and __name__ will be
+    set directly.  A location proxy will be returned otherwise.
+    """
+    if getattr(obj, '__parent__', None) is not None:
+        return obj
+    # This either sets __parent__ or wraps 'obj' in a LocationProxy
+    return zope.location.location.located(obj, parent, name)
+
+
+def applySkin(request, skin, skin_type):
+    """Change the presentation skin for this request.
+    """
+    # Remove all existing skin declarations (commonly the default skin).
+    ifaces = [iface for iface in interface.directlyProvidedBy(request)
+              if not skin_type.providedBy(iface)]
+    # Add the new skin.
+    ifaces.append(skin)
+    interface.directlyProvides(request, *ifaces)
+
+
+def application_url(request, obj, name=None, data={}):
+    """Return the URL of the nearest enclosing `grok.Application`.
+
+    Raises ValueError if no Application can be found.
+    """
+    return url(request, getApplication(), name, data)
+
+
+def create_application(factory, container, name):
+    """Creates an application and triggers the events from
+    the application lifecycle.
+    """
+    # Check the factory.
+    if not grokcore.site.interfaces.IApplication.implementedBy(factory):
+        raise WrongType(factory)
+
+    # Check the availability of the name in the container.
+    if name in container:
+        raise KeyError(name)
+
+    # Instanciate the application
+    application = factory()
+
+    # Trigger the creation event.
+    grok.notify(grok.ObjectCreatedEvent(application))
+
+    # Persist the application.
+    # This may raise a KeyError.
+    container[name] = application
+
+    # Trigger the initialization event.
+    grok.notify(grok.ApplicationInitializedEvent(application))
+
+    return application