Re: dwbp-ISSUE-206: The example with memento needs to be rewritten to use the transport example [Best practices document(s)]

Hi Herbert,

Thanks a lot for your message! We made the corrections on the example [1] .

I have another question about the Memento protocol. You said that Memento
is a protocol that "Access the version of a resource that was the current
version at a specified date/time." My question is: when we have multiple
versions of a resource how memento  identifies which version will be the
current version at a specified time? I'm sorry if this is a stupid
question, but I'm trying to find a better way to connect memento with the
BP.

Cheers,
Bernadette

[1] http://w3c.github.io/dwbp/bp.html#dataVersioning



2015-11-05 5:38 GMT-03:00 Herbert Van de Sompel <hvdsomp@gmail.com>:

> On Wed, Nov 4, 2015 at 8:13 AM, Bernadette Farias Lóscio
> <bfl@cin.ufpe.br> wrote:
> > Hi Herbert,
> >
> > I just updated the DWBP document to include the versioning example with
> > memento [1]. Thanks a lot for your contribution!
> >
> > Please, take a look and tell me if it is ok!
> >
>
> Three things:
>
> * The link to Memento info seems to have disappeared. The official
> spec is RFC7089, whereas http://mementoweb.org/howto/ has more on
> Memento and versioning.
>
> * In Example 8, it would be nice to have a blank line after each curl
> command.
>
> * Something seems to have gone wrong with the second curl in Example
> 9.  This is what it should look like:
>
> curl -i http://example.org/timemap/dataset
>
> HTTP/1.1 200 OK
> Content-Type: application/link-format
>
> <http://example.org/dataset>;rel="original”,
> <http://example.org/timegate/dataset>;rel="timegate”,
> <http://example.org/timemap/dataset>;rel="timemap”;
> type=“application/link-format”,
> <http://example.org/dataset-000>; rel=“first memento";
> datetime="Thu,05 Mar 2015 00:00:00 GMT",
> <http://example.org/dataset-001>; rel=“memento"; datetime=“Sun, 05
> Apr2015 00:00:00 GMT"
> <http://example.org/dataset-002>; rel=“last memento"; datetime="Tue,05
> May 2015 00:00:00 GMT"
>
> > I also have one question about the use of memento. If I understand
> correct,
> > Memento is a protocol that helps to obtain different versions of the same
> > resource.
>
> Memento (RFC7089) is an HTTP-based protocol that provides the
> following functionality regarding resource versions:
> * Access the version of a resource that was the current version at a
> specified date/time. This is achieved via datetime negotiation, a
> variant of content negotiation, and involves a so-called TimeGate.
> * Access the version history of a resource. This is achieved by
> obtaining a TimeMap, which lists all resource versions and their
> respective date/time.
>
> > In this case, I think we should add something on the BP to make
> > it clear that we need: i) a way to describe and to add versioning
> > information to datasets and ii) a way to access such information and to
> > access different versions of a resource. I was also wondering if instead
> of
> > having this information as part of the BP08 and BP09, it would be better
> to
> > have a specific BP related to provide access to different dataset
> versions.
> > Does it make sense for you?
> >
>
> * I think that the Memento TimeMap example in BP09 aligns well with
> the title of the BP "Provide version history", which is exactly what
> TimeMaps do. However, it fits less with the description in the "Why"
> of that BP which states "Determining how the various versions of a
> dataset differ from each other is typically very laborious unless a
> summary of the differences is provided." Memento TimeMaps merely
> provide an overview of the URIs of resource versions and their
> creation datetimes. TimeMaps provide no info on what the difference
> between the versions is, other than that they were created at
> different times. With that regard, it fits better under BP08, which is
> about uniquely identifying versions, etc.
>
> * I think you are right to suggest that the Memento example in BP08 is
> not really about "Providing version information". With that regard, as
> per the above, the TimeMap example would seem to fit better under
> BP08. The current Memento example in BP08 is about accessing a version
> of a dataset that was the "current" version at some given date/time in
> the past. This feature, as such, is not formulated as a BP. Note that
> TimeMaps can also provide this feature since they list all versions.
> But, if there are a very significant number of versions, the use of
> TimeMaps for access to a specific temporal version can be cumbersome.
>
> Since I am at it, I would like to add some thoughts related to the
> "webby" stuff that Erik and I have brought up. I think it would be
> very constructive to include an additional Best Practice about using
> typed links as a way to guide clients and applications. In this new
> Best Practice, a few examples could be provided that show HTTP
> interactions/headers that provide typed web links. The following
> examples come to mind, immediately:
> - the describes/describedby links between dataset and metadata about
> dataset, which I mailed about previously
> - prev/next links to navigate between versions of datasets
> - the Memento timemap link for access to version history
> - maybe others, for example, one using the duplicate relation type to
> link to a mirror copy
>
> Personally, I think this would be a crucial best practice to add to
> the document.
>
> Cheers
>
> Herbert
>
>
> > Thanks,
> > Bernadette
> >
> > [1] http://w3c.github.io/dwbp/bp.html#dataVersioning
> >
> >
> >
> >
> >
> > 2015-10-23 13:42 GMT-03:00 Bernadette Farias Lóscio <bfl@cin.ufpe.br>:
> >>
> >> Hi Herbert,
> >>
> >> Thanks a lot for your help! It would be great if you could help us with
> >> the rewriting of the versioning examples.
> >>
> >> Cheers,
> >> Bernadette
> >>
> >>
> >>
> >> 2015-10-23 11:40 GMT-02:00 Herbert Van de Sompel <hvdsomp@gmail.com>:
> >>>
> >>> hi all,
> >>>
> >>> => I am willing to provide material to rewrite the existing Memento
> >>> example to match the example that is used throughout the document.
> >>>
> >>> => I think that Memento should also be mentioned in the version
> >>> history section. Memento has the notion of TimeMaps, documents that
> >>> list the entire temporal version history of a resource. See
> >>> http://mementoweb.org/guide/rfc/#Pattern6-Response1 . I am willing to
> >>> provide that material too.
> >>>
> >>> Pls let me know if OK.
> >>>
> >>> Cheers
> >>>
> >>> Herbert
> >>>
> >>> On Thu, Oct 22, 2015 at 4:54 PM, Data on the Web Best Practices
> >>> Working Group Issue Tracker <sysbot+tracker@w3.org> wrote:
> >>> > dwbp-ISSUE-206: The example with memento needs to be rewritten to use
> >>> > the transport example [Best practices document(s)]
> >>> >
> >>> > http://www.w3.org/2013/dwbp/track/issues/206
> >>> >
> >>> > Raised by: Bernadette Farias Loscio
> >>> > On product: Best practices document(s)
> >>> >
> >>> > The example used in BP - Information about dataset versioning should
> be
> >>> > available is not consistent with other examples used in the document.
> >>> >
> >>> >
> >>> >
> >>>
> >>>
> >>>
> >>> --
> >>> Herbert Van de Sompel
> >>> Digital Library Research & Prototyping
> >>> Los Alamos National Laboratory, Research Library
> >>> http://public.lanl.gov/herbertv/
> >>>
> >>> ==
> >>>
> >>
> >>
> >>
> >> --
> >> Bernadette Farias Lóscio
> >> Centro de Informática
> >> Universidade Federal de Pernambuco - UFPE, Brazil
> >>
> >>
> ----------------------------------------------------------------------------
> >
> >
> >
> >
> > --
> > Bernadette Farias Lóscio
> > Centro de Informática
> > Universidade Federal de Pernambuco - UFPE, Brazil
> >
> ----------------------------------------------------------------------------
>
>
>
> --
> Herbert Van de Sompel
> Digital Library Research & Prototyping
> Los Alamos National Laboratory, Research Library
> http://public.lanl.gov/herbertv/
>
> ==
>



-- 
Bernadette Farias Lóscio
Centro de Informática
Universidade Federal de Pernambuco - UFPE, Brazil
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