- From: Andy Seaborne <andy@apache.org>
- Date: Mon, 19 May 2014 18:15:59 +0100
- To: Ivan Herman <ivan@w3.org>
- CC: W3C CSV on the Web Working Group <public-csv-wg@w3.org>
On 19/05/14 17:16, Andy Seaborne wrote:
> On 19/05/14 15:23, Ivan Herman wrote:
>> Let me try to see if I understand what you mean...
>>
>> If there is no metadata assigned to the data then (at least
>> conceptually) we say that we generate a metadata of, roughly, the form:
>>
>> {
>> "@id" : "URI OF THE DATA",
>> "columns" : [{
>> "name" : "col1",
>> "template" : "{col1},
>> },{
>> "name" : "col2",
>> "template" : "{col2},
>> }]
>> }
>
> Where we seem to differ is "template" - that's a template for one term
> (the object of a triple).
>
> The template I have in mind is a complete row:
>
> Taking from:
>
> https://github.com/w3c/csvw/blob/gh-pages/examples/simple-weather-observation.md
>
>
> Date-time, Air temperature (Cel), Dew-point temperature (Cel)
> 2013-12-13T08:00:00Z, 11.2, 10.2
>
>
> <site/22580943/date-time/20131213T0800Z>
> a ssn:Observation ;
> ssn:observationSamplingTime
> [ time:inXSDDateTime "2013-12-13T08:00:00Z"^^xsd:dateTime ] ;
> ssn:observationResult [
> a ssn:SensorOutput ;
> def-op:airTemperature_C
> [ qudt:numericValue "11.2"^^xsd:double ] ;
> def-op:dewPointTemperature_C
> [ qudt:numericValue "10.2"^^xsd:double ] ] .
>
> That could be created with a template like:
>
> ----------------------------------------------
> Columns:
>
> "columns" : [{
> "name" : "date-time"
> },{
> "name" : "air-temperature"
> },{
> "name" : "dew-point"
> }]
>
>
> ----------------------------------------------
> <site/22580943/date-time/{date-time}>
> a ssn:Observation ;
> ssn:observationSamplingTime
> [ time:inXSDDateTime "{date-time}"^^xsd:dateTime ] ;
> ssn:observationResult [
> a ssn:SensorOutput ;
> def-op:airTemperature_C
> [ qudt:numericValue "{air-temperature}"^^xsd:double ] ;
> def-op:dewPointTemperature_C
> [ qudt:numericValue "{dew-point}"^^xsd:double ] ] .
> ----------------------------------------------
>
> skipping over the conversion of 2013-12-13T08:00:00Z to 20131213T0800Z
Just to be clear - this template is not automatically generated from the
column descriptions alone - it's a more complex mapping posisble with an
explicitly provided template.
It is a contrast to 'template' used as column value (c.f. rr:template [1])
[1] http://www.w3.org/TR/r2rml/#from-template
>
> Andy
>
>>
>> And, by doing that, we have only one generation algorithm instead of
>> two branches like in my document now.
>>
>> Yes, this works, I guess. It certainly makes the specification simpler
>> and avoids getting out of sync. I am slightly worried that the
>> end-user would be a bit screwed up, but that may have to go into a
>> separate, tutorial-like text. So it may be worth doing it indeed...
>>
>> (Would need a rewrite of the text I produced, but that is probably
>> relatively easy; just that I would not do it today or tomorrow...)
>>
>> Ivan
>>
>>
>>
>> On 19 May 2014, at 16:14 , Andy Seaborne <andy@apache.org> wrote:
>>
>>> On 19/05/14 15:00, Ivan Herman wrote:
>>>>>> Generating a template, if none provided, would keep the
>>>>>> user-template driven mechanism and metadata-gdefineeneated
>>>>>> template mechanism in-step. It would be clear that they aren't
>>>>>> alternatives with (potentially) capabilities in the direct roue
>>>>>> not in the template route. You could get the generated template
>>>>>> and tweak it, for example.
>>>>>>
>>>> I would need an example to understand what you mean...
>>>>
>>>
>>> If the columns are "foo" and "bar" and no template is in the metadata
>>> then we define the process to be to create and use:
>>>
>>> -------------------------
>>> [
>>> :foo "{foo}" .
>>> :bar "{bar}" .
>>> ]
>>> -------------------------
>>>
>>> Andy
>>>
>>
>>
>> ----
>> Ivan Herman, W3C
>> Digital Publishing Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> GPG: 0x343F1A3D
>> WebID: http://www.ivan-herman.net/foaf#me
>>
>>
>>
>>
>>
>
Received on Monday, 19 May 2014 17:16:32 UTC