Package: collective.sectionsubskin
Section Sub Skin================Section Sub Skin is a system for applying an interface to a request that mapsinto a description of how a theme should change for a subsection of the site.These mappings do not automatically change things about the theme, but theyare available in Zope3 style browser views for conditional inclusion.The recommended way of doing this currently (as DTML views are not supported)is to create a view that uses TAL rather than the standard DTML method ofgenerating customised CSS files.Browser views that inherit from `collective.sectionsubskin.browser.subskin.SubSkin`have a "subskin" variable set which is accessible from the view.For example, if all subskins contain a `colour` attribute, the current colour can be found with::<tal:colour replace="view/subskin/colour" on-error="string:MyDefaultColour"/>Boring imports and setup (move to tests.py?).  You probably want to ignore all this.::>>> from zope.app.testing import ztapi>>> import zope.interface>>> from AccessControl.SecurityManagement import newSecurityManager>>> from AccessControl.User import UnrestrictedUser>>> from Testing.makerequest import makerequest>>> app = makerequest(app)>>> portal = portal.__of__(app)>>> newSecurityManager(None, UnrestrictedUser('god', '', ['Manager'], ''))>>> from Products.Five.testbrowser import Browser>>> browser = Browser()>>> from Testing.ZopeTestCase import user_password>>> browser.addHeader('Authorization', 'Basic %s:%s' % ('portal_owner', user_password)) # Only needed as our view is a dummy, if registered through ZCML we'd use permission=zope2.ViewCreating a new theme definition is very easy::>>> from collective.sectionsubskin.definition import BaseDefinition>>> from collective.sectionsubskin.interfaces import ISubskinDefinition>>> from collective.sectionsubskin.test_support import IRedSkin, RedSkinAgain, on the filesystem, the value of this code is::class IRedSkin(ISubskinDefinition):passclass RedSkin(BaseDefinition):title = u"RedSkin"colour = u"FF0000"type_interface = IRedSkinWe can keep an instance of this in a list so we can poke it later::>>> skins = []>>> skins.append(RedSkin())>>> skins[<SectionSubSkin named RedSkin>]>>> skins[0].colouru'FF0000'These are just basic python objects that inherit from BaseDefinition, whichconditionally inherits from p4a.subtyper as well as providing some helper methods.This means you can do anything with them that you can with normal objects::>>> from collective.sectionsubskin.test_support import IBlueSkin, BlueSkin>>> skins.append(BlueSkin())Again, on the filesystem, the value of this code is::class IBlueSkin(ISubskinDefinition):passclass BlueSkin(BaseDefinition):title = u"BlueSkin"colour = u"0000FF"type_interface = IBlueSkinThe skins variable now contains both skins::>>> skins[<SectionSubSkin named RedSkin>, <SectionSubSkin named BlueSkin>]>>> skins[1].colouru'0000FF'Now, if we create a browser view for the site (registed in test_support)::>>> from collective.sectionsubskin.test_support import coloursThese things need to be in filesystem code so Zope doesn't throw a paddy, so it's actually::from collective.sectionsubskin.browser.subskin import SubSkinclass colours(SubSkin):""" Colours. """def render(self):""" Render the CSS. """try:return """html { background-color: #%s; }""" % (self.subskin.colour)except:return """"""__call__ = renderdef __of__(self, parent):# We don't care about acquisition for this toy examplereturn selfWe can instantiate one directly, traverse to it or visit it in a browser::>>> colours(portal, app.REQUEST).render()''>>> portal.unrestrictedTraverse("colours.css").render()''>>> browser.open("%s/colours.css" % self.portal.absolute_url())>>> browser.contents''Only the last of these will trigger the subskin, as it only activates on HTTP requests traversing over the object.As there is no subskin active for the root it correctly renders an empty string.If, however, we create some subfolders we can assign them subskins::>>> red = portal[portal.invokeFactory("Folder","red")]>>> zope.interface.alsoProvides(red, (IRedSkin, ))>>> blue = portal[portal.invokeFactory("Folder","blue")]>>> zope.interface.alsoProvides(blue, (IBlueSkin, ))>>> noskin = portal[portal.invokeFactory("Folder","noskin")]Now when we traverse to the red folder we see the red skin::>>> browser.open("%s/red/colours.css" % self.portal.absolute_url())>>> browser.contents'html { background-color: #FF0000; }'But if we go blue we see the other option::>>> browser.open("%s/blue/colours.css" % self.portal.absolute_url())>>> browser.contents'html { background-color: #0000FF; }'Any unmarked folders still show no subskin::>>> browser.open("%s/noskin/colours.css" % self.portal.absolute_url())>>> browser.contents''Weird traversal will give the last skin encountered::>>> browser.open("%s/red/blue/colours.css" % self.portal.absolute_url())>>> browser.contents'html { background-color: #0000FF; }'and::>>> browser.open("%s/blue/red/colours.css" % self.portal.absolute_url())>>> browser.contents'html { background-color: #FF0000; }'Changelog=========0.2---Added support to the traverser to remove an existing subskin when a new definition is traversed overMatthew Wilkes0.1---Works in 2.10 well.  2.9 with Five 1.4.4 works but is unsupported.MatthewWilkes