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

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/

==

Received on Thursday, 5 November 2015 08:38:36 UTC