28 Aug
2012
28 Aug
'12
11:35 p.m.
On Tue, Aug 28, 2012 at 6:29 PM, Vincent Massol <vincent(a)massol.net> wrote:
On Aug 28, 2012, at 6:04 PM, Marius Dumitru Florea <
mariusdumitru.florea(a)xwiki.com> wrote:
It's quite the opposite. Right now, for JAR extensions stored in a Maven
Repository we extract information from the META-INF/maven/.../pom.xml file.
We don't control that at all since it's put there by Maven and in a
Maven-controlled format (which we extend by adding Maven pom properties).
As I've said a few times in this thread, I'm fine to standardize on the
Maven POM format. I'm also fine to have our own format (I called it
META-INF/xwiki/extension.xml). If we have our own format then we do control
it.
Also if we use the same strategy for all extensions (be them JAR or XAR)
the it's the opposite to what you say: we need only to implement to logic
to read META-INF/xwiki/extension.xml once whereas now we need a different
logic for each type:
* for JAR we read from the META-INF/maven/.../pom.xm
* for XAR we read from package.xml
Vincent, either I have missed something, or you have, but I do not
understand how you expect to manage all the maven dependencies that we
currently importing as dependencies of our extensions, if you choose to
have our own metadata format only ?
For package.xml it wouldn't be true because we wouldn't keep the same
On Tue, Aug 28, 2012 at 5:37 PM, Vincent Massol
<vincent(a)massol.net>
wrote:
>
> On Aug 28, 2012, at 4:26 PM, Thomas Mortagne <thomas.mortagne(a)xwiki.com>
wrote:
>
>> On Tue, Aug 28, 2012 at 4:20 PM, Vincent Massol <vincent(a)massol.net>
wrote:
>>>
>>> On Aug 28, 2012, at 3:44 PM, Thomas Mortagne <
thomas.mortagne(a)xwiki.com> wrote:
>>>
>>>> On Tue, Aug 28, 2012 at 3:35 PM, Vincent Massol
<vincent(a)massol.net>
wrote:
>>>>>
>>>>> On Aug 28, 2012, at 3:31 PM, Thomas Mortagne <
thomas.mortagne(a)xwiki.com> wrote:
>>>>>
>>>>>> On Tue, Aug 28, 2012 at 3:23 PM, Thomas Mortagne
>>>>>> <thomas.mortagne(a)xwiki.com> wrote:
>>>>>>> On Tue, Aug 28, 2012 at 3:18 PM, Vincent Massol <
vincent(a)massol.net> wrote:
>>>>>>>>
>>>>>>>> On Aug 28, 2012, at 2:50 PM, Thomas Mortagne <
thomas.mortagne(a)xwiki.com> wrote:
>>>>>>>>
>>>>>>>>> On Tue, Aug 28, 2012 at 1:37 PM, Vincent Massol <
vincent(a)massol.net> wrote:
>>>>>>>>>>
>>>>>>>>>> On Aug 28, 2012, at 1:15 PM, Thomas Mortagne <
thomas.mortagne(a)xwiki.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> Hi guys,
>>>>>>>>>>>
>>>>>>>>>>> I would like to modify a bit the Maven XAR
plugin to add in
the
>>>>>>>>>>>
package.xml some extension related informations like the
extension id
>>>>>>>>>>> and
version at the very least.
>>>>>>>>>>
>>>>>>>>>> Why not package the pom.xml instead in
META-INF/maven/* as
it's done by the Maven JAR plugin?
>>>>>>>>>
>>>>>>>>> Because it's not supposed as part of XAR format
by existing XAR
>>>>>>>>> parser, you will get an error because it will fail to
parse it
as a
>>>>>>>>> document. The
proposal here is to use something that already
exists,
>>>>>>>>> does not
break anything and is very easy to do.
>>>>>>>>
>>>>>>>> I personally much prefer to add META-INF support over
changing
the package.xml format because it's much better aligned with all
other
formats like JAR, EAR, WAR, etc and with the way we handle JAR extensions.
>>>>>>>
>>>>>>> I think you don't understand what I mean here. The issue
is not
that
>>>>>>> it's complex to
support it, adding support in 4.2 for META-INF
will
>>>>>>> not change the fact
that you will get an error in older version
with
>>>>>>> your XAR.
>>>>>>>
>>>>>>>>
>>>>>>>> It doesn't look complex to add either, it's a
matter of
excluding META-INF files from the parser and to use the Maven Archiver
(see
http://maven.apache.org/shared/maven-archiver/).
>>>>>>
>>>>>> Making the XAR format depends on Maven is not exactly something
>>>>>> generic or even very nice. Core extension scanner is looking at
the
>>>>>> pom located in jar file among other things in order to find as
much as
>>>>>> it can but lets not
forget that this is a hack and nothing else.
>>>>>
>>>>> Whatever the solution we need consistency IMO. If your proposal is
to create an extension.xml file located in META-INF/xwiki and that we would
put in all our extension types then I'm all for it too.
>>>>>
>>>>> I don't like mixing extension information with packaging
information. For me package.xml shouldn't contain extension information.
>>>>
>>>> It's exactly the same thing. The package.xml file is the XAR way to
>>>> provide informations about the file and is generated from the
pom.xml.
>>>> It already provide the a subset
of extension informations (name,
>>>> version, license, etc.) so the proposal here is about adding more
>>>> things.
>>>
>>> For me the package.xml should probably even be removed or at least a
lot of information should be removed. There's no point in listing the files
explicitly for example. Same for whether it's a backup pack or not.
>>>
>>> And a lot of the information currently in package.xml should be moved
to META-INF/xwiki/extension.xml such as author, license, version, name,
description.
>>>
>>> So I'm definitely with you about creating a XWiki-specific descriptor
(not tied to maven) located in META-INF/xwiki/extension.xml for all our
extensions, but beefing up package.xml goes in the wrong direction IMO.
>>>
>>> At the very least I'd like that we agree about where we'd like to go
(I've made a proposal with META-INF/xwiki/extension.xml) and then discuss
how to get there and what it takes. If it means going through intermediary
steps, then fine, the important part for me being to agree on where we want
to go.
>>
>> Maybe but that's a different subject and IMO it sounds like creating a
>> new packaging format for wiki pages.
>
> There are 2 topics:
> * Create a generic format for all xwiki extensions (the
META-INF/xwiki/extension.xml), nothing to do with wiki pages
> * Modify the existing XAR format descriptor
(package.xml) to remove
stuff that are 1) not needed (like the list of files and 2)
can be found in
the extension information (i.e. in META-INF/xwiki/extension.xml)
>
> So far you/we have decided that the xwiki extension format will be the
pom.xml
format which is why we are using it in our JAR file to discover
extensions. Based on that it's not logical to invent a new way to add
extension information even if the existing package.xml contains already
some information that happens (by pure coincidence) to be the same as the
one needed by the extension manager (for ex the version in package.xml
could be a completely different version than the extension version).
>
> Based on this the logic is to add the pom.xml file to the XAR.
>
> Now you said that you didn't think using the Maven format is good.
Fine.
This is a change from what we had decided so far and I'm ready to
accept that we may want to dissociate from Maven; hence my proposal about
the META-INF/xwiki/extension.xml file.
>
> So we have 2 choices for me:
> * continue with the current rule of using pom.xml files as containing
extension information
> * decide to bite the bullet and invent a new
format for holding
extension information
>
> Those are the 2 *good* choices for me. Ofc we need to handle backward
compat
as best as we can but that's doable.
>
> You'd like to do the 3rd choice which IMO is a quick and dirty
solution.
I'd accept it but only as a quick hack for 4.2 and that we would
need to correct ASAP.
>
>> I need something for 4.2 and
>> adding the id in package.xml along with the other existing extension
>> informations is quick, easy, fully retro compatible and does not
>> really introduce anything new.
>
> Sure but it does introduce something new: the new information you add
to
package.xml. And this is exactly like a public API; once it's there we
have to support it and be retro compatible. So we have to be careful
because it's a pain to change after.
I'm curious to know what others think about
this.
Thomas is proposing to add some new _optional_ information to the XAR
_descriptor_. If I understood correctly, you don't think the XAR
descriptor is the right place and you propose instead to use a
separate file. More over, you'd like that all supported extension
types use this file. In other words, you don't want the extension
manager to extract information from the descriptor specific to the
extension type but from a different file within that extension. I
think this has two problems in general:
* we need to add support for this separate file for each type of
extension (we control the code of XAR packager but this might not be
the case with other types of extension that we'd want to support in
the future) * the dedicated file will most probably duplicate
information from the
native descriptor (pom.xml, package.xml, etc.)
Yes that's true for pom.xml but it doesn't really matter. We have 2
choices:
- standardize on the pom.xml format
- use our own format
information in 2 places. We would have it in
extension.xml and not in
package.xml which would either disappear (not needed) or contain some
XAR-specific config options, or (third option) we would allow to provide
generic properties in our extension.xml format and the XAR extension type
would have whatever it needs in there.
Once again, IMO, the way extension are stored, and the way the information
about these extensions are provided to the EM, only depends on the
repository they came from. Extension stored in a maven repository will have
to use the maven way, and therefore store their extension related
information in their pom.xml. Extension coming from other repository may
have other method to provide the same information or not. It is up to the
repository.
The problem of Thomas relate to how standalone XAR could be seen as
extension and registered in the EM when these XAR are imported from outside
EM, and therefore being not installed from a repository. I have seen this
as an edge case, similar to how we register built-in extension installed in
the lib folder.
What you to talk about, is to have a more generic way to support these
standalone extensions, but you seems to apply it globally to all extensions.
IMO, you could not expect or impose that all extension coming from a Maven
repository conform to a unique way of containing meta information, since
these extensions may have been extracted from different repositories. This
would require all built-in jar and all dependencies to be repackaged
properly with the needed metadata, which would simply be counter
productive. This would also reduce the flexibility of the current system.
So, if you really want that, using pom.xml is your only choice.
That said, having a standardized, standalone packaging of extension,
independent of a repository, is something that we should think about, and
in that context, your proposal and remarks make sense to me.
I'm still +1 for what Thomas proposed.
What I've discussed in this thread is how I view this ideally. Thomas'
proposal is ok for the short term (4.2) without breaking anything existing.
When you say you're +1 do you mean you're +1
for now for 4.2 or even more
generally in the future as the right solution?
I am +1 for now and later, that extension package stored as a standalone
XAR, use the package.xml to store additional information denoting this XAR
to be a special extension XAR. It will helps current issues quickly without
breaking anything and it does not prevent to develop later a standalone
packaging for any kind of extension, that provide extension information in
a more common way.
WDYT ? Have I misunderstood the situation ?
Thanks
-Vincent
--
Denis Gervalle
SOFTEC sa - CEO
eGuilde sarl - CTO
Thanks,
Marius
>
> Thanks
> -Vincent
>
>>> Thanks
>>> -Vincent
>>>
>>>>> Thanks
>>>>> -Vincent
>>>>>
>>>>>>>> Thanks
>>>>>>>> -Vincent
>>>>>>>>
>>>>>>>>>> It would be more generic and similar to how JARs
are handled.
>>>>>>>>>>
>>>>>>>>>> Thanks
>>>>>>>>>> -Vincent
>>>>>>>>>>
>>>>>>>>>>> The idea is to be able to know what a XAR is
exactly like we
have the
>>>>>>>>>>>
pom.xml packaged with the jar file for example.
>>>>>>>>>>>
>>>>>>>>>>> Among other things it will cover the
following use cases:
>>>>>>>>>>> * when someone import a XAR with the standard
UI,
automatically
>>>>>>>>>>>
register it in the extension index if it happen to be an
extension
>>>>>>>>>>> (i.e.
if we find extension informations in its package.xml)
>>>>>>>>>>> * wiki manager and workspaces can properly
register actual
extension
>>>>>>>>>>> when
creating their default template from a XAR the first
time (this
>>>>>>>>>>> is
for example required to be able to upgrade a farm with EM
where
>>>>>>>>>>>
pretty much all the wiki as been created from this default
template)
>>>>>>>>>>>
>>>>>>>>>>> In both cases the idea is to support as much
current
behaviours as we
>>>>>>>>>>> can
and still be able to use the full power of Extension
Manager.
>>>>>>>>>>>
>>>>>>>>>>> There should not be any backward
compatibility issue here
since it
>>>>>>>>>>> does
not really change anything in the XAR structure.
>>>>>>>>>>>
>>>>>>>>>>> WDYT ?
>>>>>>>>>>>
>>>>>>>>>>> Here is my +1
_______________________________________________
devs mailing list
devs(a)xwiki.org
http://lists.xwiki.org/mailman/listinfo/devs