DAV:cannot-copy-collection-version precondition for COPY

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DAV:cannot-copy-collection-version precondition for COPY

Werner Donné

Hi,

Why should the request fail if the source is a collection version?
It seems to me that any version is as good as the checked-in version
to copy from.

Regards,

Werner.
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Re: DAV:cannot-copy-collection-version precondition for COPY

Geoffrey M Clemm

A collection version does not have enough information in it to produce a sensible copy, since it only records the version history of its members, not the versions.  So a collection version is useful for updating a configuration, but is not useful for creating a new configuration (that's what baselines are for).

Cheers,
Geoff

[hidden email] wrote on 08/22/2006 06:34:16 AM:

>
> Hi,
>
> Why should the request fail if the source is a collection version?
> It seems to me that any version is as good as the checked-in version
> to copy from.
>
> Regards,
>
> Werner.
> --
> Werner Donné  --  Re
> Engelbeekstraat 8
> B-3300 Tienen
> tel: (+32) 486 425803   e-mail: [hidden email]
>
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Re: DAV:cannot-copy-collection-version precondition for COPY

Werner Donné

A collection version has the names of its version controlled bindings
and their version history. It is then possible to find the checked-in
version of the members, which is what is used also when a collection
is copied.

Regards,

Werner.

Geoffrey M Clemm wrote:

>
> A collection version does not have enough information in it to produce a
> sensible copy, since it only records the version history of its members,
> not the versions.  So a collection version is useful for updating a
> configuration, but is not useful for creating a new configuration
> (that's what baselines are for).
>
> Cheers,
> Geoff
>
> [hidden email] wrote on 08/22/2006 06:34:16 AM:
>
>>
>> Hi,
>>
>> Why should the request fail if the source is a collection version?
>> It seems to me that any version is as good as the checked-in version
>> to copy from.
>>
>> Regards,
>>
>> Werner.
>> --
>> Werner Donné  --  Re
>> Engelbeekstraat 8
>> B-3300 Tienen
>> tel: (+32) 486 425803   e-mail: [hidden email]
>>

--
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Re: DAV:cannot-copy-collection-version precondition for COPY

Manfred Baedke
Hi Werner,

taking into account the postcondition (DAV:must-not-copy-versioning-property) and the fact that the property DAV:version-controlled-binding-set is more or less all a collection version has to offer, there is nothing left to be copied.

Regards,
Manfred

Werner Donné wrote:
A collection version has the names of its version controlled bindings
and their version history. It is then possible to find the checked-in
version of the members, which is what is used also when a collection
is copied.

Regards,

Werner.

Geoffrey M Clemm wrote:
  
A collection version does not have enough information in it to produce a
sensible copy, since it only records the version history of its members,
not the versions.  So a collection version is useful for updating a
configuration, but is not useful for creating a new configuration
(that's what baselines are for).

Cheers,
Geoff

[hidden email] wrote on 08/22/2006 06:34:16 AM:

    
Hi,

Why should the request fail if the source is a collection version?
It seems to me that any version is as good as the checked-in version
to copy from.

Regards,

Werner.
--
Werner Donné  --  Re
Engelbeekstraat 8
B-3300 Tienen
tel: (+32) 486 425803   e-mail: [hidden email]

      

  
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Re: DAV:cannot-copy-collection-version precondition for COPY

Werner Donné

Hi Manfred,

What does a version controlled collection have more to allow it
to be copied?

Regards,

Werner.

Manfred Baedke wrote:

> Hi Werner,
>
> taking into account the postcondition
> (DAV:must-not-copy-versioning-property) and the fact that the property
> DAV:version-controlled-binding-set is more or less all a collection
> version has to offer, there is nothing left to be copied.
>
> Regards,
> Manfred
>
> Werner Donné wrote:
>> A collection version has the names of its version controlled bindings
>> and their version history. It is then possible to find the checked-in
>> version of the members, which is what is used also when a collection
>> is copied.
>>
>> Regards,
>>
>> Werner.
>>
>> Geoffrey M Clemm wrote:
>>  
>>> A collection version does not have enough information in it to produce a
>>> sensible copy, since it only records the version history of its members,
>>> not the versions.  So a collection version is useful for updating a
>>> configuration, but is not useful for creating a new configuration
>>> (that's what baselines are for).
>>>
>>> Cheers,
>>> Geoff
>>>
>>> [hidden email] wrote on 08/22/2006 06:34:16 AM:
>>>
>>>    
>>>> Hi,
>>>>
>>>> Why should the request fail if the source is a collection version?
>>>> It seems to me that any version is as good as the checked-in version
>>>> to copy from.
>>>>
>>>> Regards,
>>>>
>>>> Werner.
>>>> --
>>>> Werner Donné  --  Re
>>>> Engelbeekstraat 8
>>>> B-3300 Tienen
>>>> tel: (+32) 486 425803   e-mail: [hidden email]
>>>>
>>>>      
>>
>>  

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Re: DAV:cannot-copy-collection-version precondition for COPY

Geoffrey M Clemm
In reply to this post by Werner Donné

It sounds like you are suggesting that the result of the copy depend on what is in the target of the copy?  That would be very strange "copy" behavior (i.e. the result of the copy should only depend on the source of the copy).  Collection versions are for use by "merge" and "update".

Cheers,
Geoff

Werner Donné <[hidden email]> wrote on 08/22/2006 10:59:59 AM:

> A collection version has the names of its version controlled bindings
> and their version history. It is then possible to find the checked-in
> version of the members, which is what is used also when a collection
> is copied.
>
> Regards,
>
> Werner.
>
> Geoffrey M Clemm wrote:
> >
> > A collection version does not have enough information in it to produce a
> > sensible copy, since it only records the version history of its members,
> > not the versions.  So a collection version is useful for updating a
> > configuration, but is not useful for creating a new configuration
> > (that's what baselines are for).
> >
> > Cheers,
> > Geoff
> >
> > [hidden email] wrote on 08/22/2006 06:34:16 AM:
> >
> >>
> >> Hi,
> >>
> >> Why should the request fail if the source is a collection version?
> >> It seems to me that any version is as good as the checked-in version
> >> to copy from.
> >>
> >> Regards,
> >>
> >> Werner.
> >> --
> >> Werner Donné  --  Re
> >> Engelbeekstraat 8
> >> B-3300 Tienen
> >> tel: (+32) 486 425803   e-mail: [hidden email]
> >>
>
> --
> Werner Donné  --  Re
> Engelbeekstraat 8
> B-3300 Tienen
> tel: (+32) 486 425803   e-mail: [hidden email]
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Re: DAV:cannot-copy-collection-version precondition for COPY

Julian Reschke
In reply to this post by Werner Donné

Werner Donné schrieb:
> Hi Manfred,
>
> What does a version controlled collection have more to allow it
> to be copied?
>
> Regards,
>
> Werner.

A version controlled collection has properties, potentially content
(edge case), and members. I'd say that's a lot of stuff that can be
copied. :-)

Best regards, Julian

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Re: DAV:cannot-copy-collection-version precondition for COPY

Werner Donné
In reply to this post by Geoffrey M Clemm

Geoff,

I thought that a version of a collection represented the state of
that collection at a certain point. So the version-controlled-binding-set,
which is a collection version property, contains the binding names
that correspond to the members of the collection at that version.
If collection /a has members b and c at a certain point, then the
version of the collection corresponding to this would have binding
names b and c.

Given a version of a VCR, a system can find that VCR. If our VCR is
collection /a and if we have binding names b and c in the collection
version, we can reconstruct /a/b and /a/c. Now we have enough to
create a new collection with members b and c.

I don't find that very strange. What is the difference between copying
a collection version to another collection, leading to a new version
controlled collection in the latter, and copying a version controlled
collection with a label header. Precondition must-select-version-in-history
in section 8.7 results in some collection version to be used for the
copy. I could also have specified that collection version directly in
the request URI.

Regards,

Werner.

Geoffrey M Clemm wrote:

>
> It sounds like you are suggesting that the result of the copy depend on
> what is in the target of the copy?  That would be very strange "copy"
> behavior (i.e. the result of the copy should only depend on the source
> of the copy).  Collection versions are for use by "merge" and "update".
>
> Cheers,
> Geoff
>
> Werner Donné <[hidden email]> wrote on 08/22/2006 10:59:59 AM:
>
>> A collection version has the names of its version controlled bindings
>> and their version history. It is then possible to find the checked-in
>> version of the members, which is what is used also when a collection
>> is copied.
>>
>> Regards,
>>
>> Werner.
>>
>> Geoffrey M Clemm wrote:
>> >
>> > A collection version does not have enough information in it to produce a
>> > sensible copy, since it only records the version history of its members,
>> > not the versions.  So a collection version is useful for updating a
>> > configuration, but is not useful for creating a new configuration
>> > (that's what baselines are for).
>> >
>> > Cheers,
>> > Geoff
>> >
>> > [hidden email] wrote on 08/22/2006 06:34:16 AM:
>> >
>> >>
>> >> Hi,
>> >>
>> >> Why should the request fail if the source is a collection version?
>> >> It seems to me that any version is as good as the checked-in version
>> >> to copy from.
>> >>
>> >> Regards,
>> >>
>> >> Werner.
>> >> --
>> >> Werner Donné  --  Re
>> >> Engelbeekstraat 8
>> >> B-3300 Tienen
>> >> tel: (+32) 486 425803   e-mail: [hidden email]
>> >>
>>
>> --
>> Werner Donné  --  Re
>> Engelbeekstraat 8
>> B-3300 Tienen
>> tel: (+32) 486 425803   e-mail: [hidden email]

--
Werner Donné  --  Re
Engelbeekstraat 8
B-3300 Tienen
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Re: DAV:cannot-copy-collection-version precondition for COPY

Geoffrey M Clemm

COPY has to obey the semantics defined for it by RFC-2518 (so that an RFC-2518 client can interoperate with an RFC-3253 server), or must fail.
Since a collection version is a resource with no members, the result of a successful COPY of a collection version would have to be the creation of a destination resource with no children.  Since this is unlikely to be the behavior that a versioning client would want, the COPY request is defined to fail.

Cheers,
Geoff


Werner wrote on 08/22/2006 04:24:25 PM:
> I thought that a version of a collection represented the state of
> that collection at a certain point. So the version-controlled-binding-set,
> which is a collection version property, contains the binding names
> that correspond to the members of the collection at that version.
> If collection /a has members b and c at a certain point, then the
> version of the collection corresponding to this would have binding
> names b and c.
>
> Given a version of a VCR, a system can find that VCR. If our VCR is
> collection /a and if we have binding names b and c in the collection
> version, we can reconstruct /a/b and /a/c. Now we have enough to
> create a new collection with members b and c.
>
> I don't find that very strange. What is the difference between copying
> a collection version to another collection, leading to a new version
> controlled collection in the latter, and copying a version controlled
> collection with a label header. Precondition must-select-version-in-history
> in section 8.7 results in some collection version to be used for the
> copy. I could also have specified that collection version directly in
> the request URI.

> Geoffrey M Clemm wrote:
> > It sounds like you are suggesting that the result of the copy depend on
> > what is in the target of the copy?  That would be very strange "copy"
> > behavior (i.e. the result of the copy should only depend on the source
> > of the copy).  Collection versions are for use by "merge" and "update".

> > Werner Donné <[hidden email]> wrote on 08/22/2006 10:59:59 AM:
> >> A collection version has the names of its version controlled bindings
> >> and their version history. It is then possible to find the checked-in
> >> version of the members, which is what is used also when a collection
> >> is copied.

> >> Geoffrey M Clemm wrote:
> >> > A collection version does not have enough information in it to produce a
> >> > sensible copy, since it only records the version history of its members,
> >> > not the versions.  So a collection version is useful for updating a
> >> > configuration, but is not useful for creating a new configuration
> >> > (that's what baselines are for).

> >> > Werner wrote on 08/22/2006 06:34:16 AM:
> >> >> Why should the request fail if the source is a collection version?
> >> >> It seems to me that any version is as good as the checked-in version
> >> >> to copy from.
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Re: DAV:cannot-copy-collection-version precondition for COPY

Manfred Baedke
In reply to this post by Werner Donné

Hi Werner,

> Given a version of a VCR, a system can find that VCR.
I do not see how this could generally be done.

Regards,
Manfred

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Re: DAV:cannot-copy-collection-version precondition for COPY

Manfred Baedke
In reply to this post by Julian Reschke

Well, admitted that in the case of a version-controlled collection with
content and dead properties, a version of this collection also had
content and dead properties, which one might indeed want to copy.
But I do not think that this is really an issue.

Regards,
Manfred

Julian Reschke wrote:

>
> Werner Donné schrieb:
>> Hi Manfred,
>>
>> What does a version controlled collection have more to allow it
>> to be copied?
>>
>> Regards,
>>
>> Werner.
>
> A version controlled collection has properties, potentially content
> (edge case), and members. I'd say that's a lot of stuff that can be
> copied. :-)
>
> Best regards, Julian
>


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Re: DAV:cannot-copy-collection-version precondition for COPY

Werner Donné
In reply to this post by Manfred Baedke

Hi Manfred,

In general it is indeed not possible, but given the fact
that both VCRs and versions have the version-history
property an implementation could be able to do that.

Regards,

Werner.

Manfred Baedke wrote:
> Hi Werner,
>
>> Given a version of a VCR, a system can find that VCR.
> I do not see how this could generally be done.
>
> Regards,
> Manfred
>
>

--
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