Stephan Richter wrote:
the following helper functions in zope.app.component do not work well with the
new registry concept of bases: getNextSiteManager, queryNextSiteManager,
Those methods expect a simple lookup tree, where the first base of a local
registry is the registry its parent's site manager's registry or the global
registry; in other words, always the first base is selected (line 45). Since
I started using the baseregistry, I commonly add the base registries at the
first position, since I want them to override the global and other parent
registries. Doing so breaks all components that use the above helper
functions. Here is the solution I am going to check in later today:
These functions will be deprecated, since they simply make no sense with the
current design of the registries. I have checked the core code and they are
not used anywhere except for queryNextUtility. I suspect the same to be true
for all 3rd-party code as well, so that deprecating them should not really
Yes, it seems they're a relic of the old lookup tree and probalby
should've been deprecated along with the 'next' attriubte of site managers.
They are still very useful and their extensive use in the Zope 3 core code is
proof of that. Luckily their fix is simple. Instead of using
get/queryNextSiteManager to look up the next registry, we simply iterate
through all the bases of the closest site manager until an answer is found.
This way the lookup pattern will work as before and supports the new usage
pattern. I have tested this fix and it works for my code well.
The really big question is: Is that change worth porting to the Zope 3.3
If you're talkign about get/queryNextUtility, then yes, I think so. The
deprecation of get/queryNextSiteManager cannot land in 3.3, of course.
It really is a serious bug that will cause people painful error
messages that are hard to understand. Also, it prevents people from using
Zope 3.3 and z3c.baseregistry.
Well, it's not quite as black and white as that, but I can see how the
lack of this bugfix makes it at least very hard to serve our component
lookup registries with z3c.baseregistry.
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