[Zope-dev] ZPT attributes and ""

[Christian Theune]

On Tue, 2009-03-10 at 10:50 -0400, Tres Seaver wrote:
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> Malthe Borch wrote:
> > 2009/3/10 Fred Drake <fdrake at gmail.com>:
> >> The change would need to be in zope.tal.
> > 
> > True.
> > 
> >> I'm ambivalent; while it makes sense to me in isolation, the affect on
> >> existing templates is undesirable, and compatibility is a huge deal
> >> for this bit of machinery.
> > 
> > I agree, but it would be interesting to gauge the usage of this
> > functionality (e.g. if everyone could put a breakpoint in the right
> > place, run their apps and check).
> > 
> > Actually, I think this is a bug; why would the empty string not be
> > printed? If we can agree it's a bug, then I guess it should be fixed
> > as part of the general maintenance of the package.
> > 
> > At any rate, if we did change/fix the behavior, a warning should
> > probably be issued. If an attribute == "" then log a warning such as
> > "The behavior of this has changed. Make sure your templates are
> > updated."
> 
> It seems like we ought to start emitting the warnings first, and then
> fold in the new behavior as the default later.  Maybe we could allow
> some kind of configuration to enable the newer behavior sooner.

Ack. Not being able to produce empty attributes is a bug.

Fixing it might break apps. Adding an option to enable it first and then
moving this to a default setting later is a good way to go, IMHO.

I'm not sure how to time the move, though.  One option would be to
release a bugfix with the option as non-default and a feature release
with the option as default.

Christian

-- 
Christian Theune · ct at gocept.com
gocept gmbh & co. kg · forsterstraße 29 · 06112 halle (saale) · germany
http://gocept.com · tel +49 345 1229889 7 · fax +49 345 1229889 1
Zope and Plone consulting and development
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