Chris wrote: I assume these caveats are spelled out here because Z3 developers don't want to slow down Z3 development to test/maintain Z2 compatibility. I know a lot about Z2 code, but I know very little about Z3 code. I'd like that to change, but it's likely that I'll just not have the bandwidth to make sure Z3-inside-Z2 works. If that just means I can't use Z3 features but nothing else breaks, it's probably fine, but if Z3 integration actively breaks Z2, it's likely I'll just need for some extended period of time to continue to use and maintain 2.7.
It'd be great if active Z3 developers could actually help make new releases of Z2 once Five is integrated but the above makes it sound like a "we'll throw it over the wall and you make it work" sort of thing. If it's the latter, maybe as devil's advocate, I need to ask what the point is here?
It appears there is an assumption that merging Z2 and Z3 code within Z2 itself is an unmitigated good thing, but IMHO, each is complicated enough in their own right that I'd personally prefer to be dealing with one or the other at any given time and not both. This isn't exactly idle whining either, I need to do this when I maintain Z4I code, and it's definitely not a walk in the park; it's moderately difficult to do and also difficult find people who have the skills to help too.
Does anyone else share this skepticism or am I about to get shouted down? ;-)
- C
A lot of time was spent talking about these (legitimate) concerns - unfortunately it will probably take a little time to distill all of that communication to the community. But let me take a shot ;) There are several different groups, with different goals and concerns, who are involved here: A: Z2 developers that don't care right now about Z3 B: Z2 developers that care about Z3, but can't effectively use anything Z3 related right now because it is not practical or possible to switch wholesale and there is no bridge to Z3 that doesn't require throwing away existing investments in Z2 C: Z3 developers that don't care about Z2 anymore, often because they dont have existing investments in Z2 There are a significant and growing number of people in group B. At the paris sprint, we were looking for a way to: - Allow folks in group B to start taking advantage of (and developing an interest in and contributing to!) Zope 3 technologies - Make sure that group A would not be 'forced' to do anything they don't want to do - Make sure that group C would not be 'forced' to do anything they don't want to do I feel that the approach of integrating Five into Zope officially does a pretty good job of meeting those goals. We added the Five product and a snapshot of Zope X3.0 into the core so that people could have a reliable baseline 'out of the box'. That integration touched almost nothing in the Z2 code (one or two things that were previously done as monkey patches were un-monkeyed, but that's about it). The Z3 code (and the Five code) just sits there unused unless you choose to use it, so Zope3 code breaking Z2 apps is not really a concern. But is there and available, so people can begin to plot their own migration paths based on their own situations. Like other areas of Z2 (and Z3, for that matter), contributors tend to develop areas of expertise. A new area of expertise for Z2 going forward will be the Five/Z3 integration, and there will be a set of devs who will likely focus on that aspect. I don't expect that the fact that Five and Z3 integration exists will make life any harder for someone who focuses on purely Z2 aspects of the core anytime soon. So the short answer is, we tried really hard to make sure to take an approach where z3 integration would not actively break zope2 in any way or force people into any particular direction. I *do* expect these (good) questions to recur in future Z2 releases, as integration and ability to use Z3 technologies increases, but we'll have plenty of time to work those out. For now, I think it is a huge win to make some Z3 avenues available to people who want to use them, without forcing everyone to drink the kool-aid at once ;) Brian Lloyd brian@zope.com V.P. Engineering 540.361.1716 Zope Corporation http://www.zope.com