[Zope-dev] Proposal: refactoring of zope.app.security

[Dan Korostelev]

Hi people!

One of most large packages that really wants to be refactored but
still wasn't touched is zope.app.security. It has much in it and it
brings many dependencies, including zope.app.form and company. And
even some zope.* packages, like zope.securitypolicy still depend on
it. So, let's finally refactor it :)

Here's a sketch of a refactoring plan I wrote after taking a quick
look at the current package:

- Move IAuthentication and other interfaces into new
zope.authentication package. Also move there PrincipalSource and the
"checkPrincipal" utility function. Also move there the PrincipalTerms
class, however that will add dependency on zope.browser (which is
really really tiny, as you may know).

- Move global principal registry, its IPrincipal/IGroup
implementations and its directives into new zope.principalregistry
package.

- Move LocalPermission into new zope.localpermission package. I
personally didn't ever need local permissions.

- Rewrite PermissionsVocabulary and PermissionIdsVocabulary not to
depend on zope.app.component and move them into zope.security. It's
generally useful there and won't introduce any new dependencies.

- Move zcml definition of zope.Public permission. Maybe move security
declaration for the `zope.security.permission.Permission` class as
well.

- Leave all browser views, globalmodules.zcml, _protections.zcml,
other zope.* permission definitions in zope.app.security as well as
backward-compatibility imports.

- Just to note: the "settings" module was recently moved to
zope.securitypolicy as there's the right place for it.

Not sure about:

- ILoginPassword and its basic implementations. The interface should
probably go into zope.authentication while implementations - into
zope.publisher. It will add a dependency on zope.authentication to
zope.publisher, but the zope.authentication are expected to be really
tiny and already installed for most applications, so I believe that
it's okay.

- PrincipalLogging - the adapter from
zope.security.interfaces.IPrincipal to
zope.publisher.interfaces.ILoggingInfo. I'd just move it into
zope.publisher, because it's already tied to zope.security.

- ILogoutSupported flag interface/adapter. Looks like it's only ever
used for enabling/disabling the "logout" button in the UI. I'd
deprecate it and leave in zope.app.security.

- _protections.py module. It defines a NoProxy checker for
zope.i18nmessageid.Message and adds __name__ and __parent__ attributes
to _available_by_default. This module was executed in
zope.app.security.__init__ and generally does useful things for most
of applications. The problem is that neither zope.i18nmessage, nor
zope.location already depend on zope.security. One solution is to move
the protections in that packages, placing the code into "try/except
ImportError" block to avoid hard dependency.

-- 
WBR, Dan Korostelev