On Thu, Mar 29, 2012 at 08:20, Vincent Massol <vincent(a)massol.net> wrote:
Hi Caleb,
On Mar 28, 2012, at 11:28 PM, Caleb James DeLisle wrote:
On 03/28/2012 02:03 PM, Vincent Massol wrote:
>
> On Mar 28, 2012, at 7:10 PM, Denis Gervalle wrote:
>
>> On Wed, Mar 28, 2012 at 12:27, Vincent Massol <vincent(a)massol.net>
wrote:
>>
>>> Hi devs,
>>>
>>> I'd like to change our deprecation strategy. Here's what we are
currently
>>> supposed to use (we voted it a long
time ago):
>>>
>>>
http://dev.xwiki.org/xwiki/bin/view/Community/DevelopmentPractices#HDepreca…
>>>
>>> "
>>> In addition our rule is to keep @deprecated methods/classes for 2
final
>>> releases after the version where they
were first added has been
released as
>>> final.
>>> For example if a method is deprecated in, say XE 1.3M2 then the method
>>> will be removed in 1.6M1 or after. Of course any major new release can
>>> deprecate anything. For example a XWiki 2.0 release is allowed to
break
>>> backward compatibility (obviously we
need to be careful to offer a
>>> migration path for users of previous major versions).
>>> "
>>>
>>> Issues:
>>> * This seems a bit harsh to me for some of our users/devs in the
community.
>>> * We're not following which
proves to me it's not a good rule
>>> * It doesn't say anything about Scripting APIs which require a greater
>>> stability in order not to break all wiki pages
>>>
>>> Definition of a Scripting API:
>>> * a Script Service (that's the new way of providing script apis)
>>> * a class in the "api" package in xwiki-platform-oldcore (this is
the
old
>>> way of providing script apis)
>>>
>>> Thus I'd like to propose this new rule:
>>>
>>> * Deprecated methods can only be removed in the next Release Cycle.
For
>>> example something deprecated in
version N.x can be removed in version
N+1.y
>>> where x and y can be anything. This
is logical since N+1 means a new
major
>>> release and it's common to
understand that major releases have no
guarantee
>>> of API compatibility (See
http://en.wikipedia.org/wiki/Software_versioningfor example).
>>> * For scripting APIs we can remove
deprecated API only after 4 Release
>>> Cycles. For example since we're in 4.x this means we
>>
>>
>> Why four ? isn't it too much ?
>
> The reason I proposed 4 is because nowadays there still are quite a few
XWiki
1.x instances in the wild so if people have coded apps on 1.x and
then upgrade to 4.0 (for ex) it would be nice if their app still works.
However I think it's ok to not support apis done in 0.9. And next year it
would be ok to drop 1.x api support, etc.
>
> It's long but then we can see in the wild that it's important we
provide stable scripting apis for users since they're used a lot while java
apis are used by more savvy user (developers) and thus having a shorter
removing cycle for them (1 year) should be ok.
What would you like to propose instead?
I'd rather we had no hard rules lest dogmatic adherence to the rules
becomes
an excuse not to fulfill our obligation to do what's best for the
software.
I'm not exactly sure what `break' means
since there's no reason I can
see for these functions to be removed from the
compatibility aspect.
The reason for having a well-defined rule is:
* I think it's better than having to send a vote every time we want to
remove a deprecated api. It certainly is much simpler.
* Publicly document it so that our users will know about this rule and
adapt their deprecation replacement strategy as a consequence
I really think we ought to publish our deprecation and removal policy.
I propose:
#1 Move remaining deprecated scripting API methods from oldcore into
legacy-oldcore compatibility aspect.
That means these:
http://nexus.xwiki.org/nexus/service/local/repositories/releases/archive/or…
This is *already* our strategy, see the "2-step" strategy defined here:
http://dev.xwiki.org/xwiki/bin/view/Community/DevelopmentPractices#HDepreca…
Everyone is already supposed to do this and do this regularly. The issue
is that before being able to move a lot of code we need to fix a lot of
deprecation usages.
<OT>It could be nice to organize a "deprecation day" where we try to
squash as many deprecation usages as possible</OT>
#2 Get xwiki-enterprise building and testing with
xwiki-platform-oldcore
instead of xwiki-platform-legacy-oldcore.
Add an xwiki-enterprise-legacy-jetty-hsql build
profile so that we can
test in parallel, with and without legacy-oldcore.
I ran the UI tests and it appears that we have a
few dependencies on
legacy-oldcore. IMO this is very bad.
This is very very bad and goes against our current policy indeed.
However it doesn't look like we have too
many.
Lets get it running, see the failing tests, report the issues, then fix
them.
This is a very good idea and I'm all for it.
#3 Stop shipping legacy-oldcore by default. Users
can always swap
platform-oldcore for it on their own.
It's not just oldcore, we have several legacy modules and theoretically we
can have as many as we have modules.
I don't think we cans stop shipping a distribution with legacy modules but
what would be nice is to start shipping a distribution without legacy
modules. We could even highlight this one as first listed to raise
awareness.
Couldn't this be achieved (in most case) using a legacy extension
installable from the extension manager ?
I am not sure providing two distribution is good, it increase the work to
release, it increase the complexity for newcomer, ...
#4 Aggressively move deprecated internal
(non-script api) code into the
compatibility aspect, this will allow us to simplify
the oldcore, and
potentially even remove dependencies.
This is already our strategy. Again for some cases it's hard but I'm all
for it. A lot of us introduce new APIs but don't update the code to use the
new API creating a lot of deprecation usages suddenly. I'm all for this
too.
If we want to stall, we can stall at #3, having
1, 2, and some of 4
taken care of will make the final decision the flip of a
switch.
This is all great but it doesn't solve the VOTE. It's a different topic
and something we've already VOTED and doing. I agree it would be nice to do
it more aggressively but it's very different from the deprecation policy
I'd like to find an agreement on.
Unless I misunderstood you and your proposal is to NEVER remove deprecated
APIs, which is a solution of course. I'm a bit afraid of the consequences.
BTW I'd like to update our current strategy documentation to a 3-step
strategy:
* Step 1: deprecate
* Step 2: move to legacy modules (this means removing our usages of the
deprecated apis)
* Step 3: remove from legacy modules <-- This is what we're voting on here
i.e. we could do step3 only when we've done steps 1 and 2 first. This is a
good strategy IMO because it means that we would have done step2 which is
required to be able to remove a deprecated api anyway… ;)
I fully agree. Why not reduce our engagement to keep an API to a shorter
period, the one proposed by Thomas seems reasonable to me, and at the same
time, keep in legacy as much as possible, even after that period elapse ?
Only removing what became really too hard to maintain, but only when the
initial period elapse.
Thanks
-Vincent
Caleb
>
> Thanks
> -Vincent
>
>>> can remove deprecated APIs from 0.x releases. And when we start 5.x we
>>> will be able to remove deprecated scripting apis deprecated in 1.x.
>>>
>>> Here's my +1
>>>
>>> Thanks
>>> -Vincent
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