Implementing ore isaggregatedby
This presentation is the property of its rightful owner.
Sponsored Links
1 / 11

Implementing ore:isAggregatedBy PowerPoint PPT Presentation


  • 42 Views
  • Uploaded on
  • Presentation posted in: General

Implementing ore:isAggregatedBy. Michael L. Nelson ORE TC Meeting Washington DC, Jan 14-15 2007. Summary.

Download Presentation

Implementing ore:isAggregatedBy

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Implementing ore isaggregatedby

Implementing ore:isAggregatedBy

Michael L. Nelson

ORE TC Meeting

Washington DC, Jan 14-15 2007


Summary

Summary

  • Beginning as a more specific relationship of “lineage” or “reference in context”, ore:isAggregatedBy is now “just” the (sometimes explicit, sometimes implicit) complimentary relationship to ore:aggregates

  • Issues:

    • Atom provides two methods of implementing our original idea of “lineage”: source & via. Only via corresponds to ore:isAggregatedBy; source has no representation in the ORE ADM. This has the potential danger of one serialization being more expressive than the model.

    • HTML cannot express ore:isAggregatedBy (both by limitation of HTML and the ORE ADM). Depending on one’s tolerance for “hacks”, there may be utility in supporting our original notion of “lineage” by providing HTML hints for ReM discovery.


A 3 acknowledges that ar 3 isaggregatedby a 1 a 2

A-3 Acknowledges That AR-3 “isAggregatedBy” A-1 & A-2


Aggregation ar 1 acknowledges it is recursively included in aggregation a 1

Aggregation AR-1 Acknowledges it is Recursively Included in Aggregation A-1


Feed entry source vs feed entry link @rel via @href

source

source=???

source

source

ReM 1

ReM 2

ReM 3

ReM 4

via=isAggregatedBy

via

via

via

/feed/entry/source vs. /feed/entry/link[@rel="via"][email protected]

  • source always “points” to 1st ReM

    • “points”=by-value

  • via always “points” to n-1 ReM

    • “points”=by-reference

  • XML examples:

    • original ReM: http://www.openarchives.org/ore/0.1/atom-implementation#SplashPages

    • source: http://www.openarchives.org/ore/0.1/atom-implementation#source

    • via: http://www.openarchives.org/ore/0.1/atom-implementation#entrylink


Impact of source

Impact of Source

  • Using source likely to be part of Atom idiom

  • This statement is not likely to be true:

    rem.atom == rdf2atom(atom2rdf(rem.atom))

  • This is not without precedent (see tables 2 & 3 of http://www.openarchives.org/ore/0.1/atom#ORE_ATOM), but the distinction is that source expresses something more fundamental than the other unmapped, Atom-specific feed & entry elements (e.g., id, title)


Embedding links to rems in web resources

Embedding Links to ReMs in Web Resources

  • HTML <link> elements and even opaque strings exposed to the user are obvious ways to associate an AR with its ReM

    • http://www.openarchives.org/ore/0.1/discovery#ResourceEmbedding

  • But it is possible to support the original notion of “lineage”, at least in the context of ReM discovery, by instrumenting HTML <A> and <IMG> elements. Unfortunately, there are tradeoffs between utility, correctness and ease. Three possible solutions follow, 2 listed in the Discovery document and 1 new one.


Html option 1 resourcemap attribute

HTML Option #1: resourcemap attribute

<html>

...

Here is a helpful reference for distinguishing

<a href="http://example.org/pics/f-t.pdf"

resourcemap="http://example.org/amphibians.atom">frogs vs. toads</a>.

<p>

Here is a frog

<img src="http://weluvfrogs.org/imgs/frog12.jpeg"

resourcemap="http://frogs.org/frogs.atom">

and here is a toad <img src="http://toadsrule.org/toad.gif"

resourcemap="http://toadsrule.org/toads.atom">.

...

</html>

Pro: very simple, human readable

Con: invalid HTML


Html option 2 a rel attribute

HTML Option #2: <A> rel attribute

<html>

...

Here is a helpful reference for distinquishing

<a href="http://example.org/pics/f-t.pdf"

rel="resourcemap=http://example.org/amphibians.atom">frogs vs. toads</a>.

<p>

Here is a frog

<a rel="resourcemap=http://frogs.org/frogs.atom">

<img src="http://weluvfrogs.org/imgs/frog12.jpeg">

</a> and here is a toad

<a rel="resourcemap=http://toadsrule.org/toads.atom">

<img src="http://toadsrule.org/toad.gif">

</a>.

...

</html>

Pro: Valid HTML

Con: Not uniform (<A> and <IMG> do not (yet) support the same elements)


Html option 3 span elements

HTML Option #3: <span> elements

<html>

...

Here is a helpful reference for distinguishing

<span class="resourcemap=http://example.org/amphibians.atom">

<a href="http://example.org/pics/f-t.pdf" frogs vs. toads</a>.

</span>

<p>

Here is a frog

<span class="resourcemap=http://frogs.org/frogs.atom">

<img src="http://weluvfrogs.org/imgs/frog12.jpeg">

</span> and here is a toad

<span class="resourcemap=http://toadsrule.org/toads.atom">

<img src="http://toadsrule.org/toad.gif">

</span>.

...

</html>

Pro: Valid HTML, Uniform Approach

Con: No longer simple?


Html option 4 class attribute

HTML Option #4: class attribute

<html>

...

Here is a helpful reference for distinguishing

<a href="http://example.org/pics/f-t.pdf"

class="resourcemap=http://example.org/amphibians.atom">frogs vs. toads</a>.

<p>

Here is a frog

<img src="http://weluvfrogs.org/imgs/frog12.jpeg"

class="resourcemap=http://frogs.org/frogs.atom">

and here is a toad <img src="http://toadsrule.org/toad.gif"

class="resourcemap=http://toadsrule.org/toads.atom">.

...

</html>

Pro: very simple, human readable, valid HTML

Con: overloads “class”*

*http://www.w3.org/TR/REC-html40/struct/global.html#adef-class

The class attribute has several roles in HTML:

* As a style sheet selector (when an author wishes to assign style information to a set of elements).

* For general purpose processing by user agents.


  • Login