Yads

YADS – A D escription S ervice Tony Hammond Nature Publishing Group

“ Down in Hollywood” “ Going down in Hollywood You better hope that you don't run out of gas Down in Hollywood He'll drag you right out of your car and kick your ass Down in Hollywood They're standing on a corner waiting for a sucker like you Down in Hollywood Now, if you want to stay healthy just keep a-moving right on through” – Ry Cooder, Bop Till You Drop

YADS – “Down in Hollywood”

YADS – Balance Sheet

Caveats

Like Lazarus – Newly Arisen

Legacy DOI Roots

Work in Progress

Open Issues

Features

Body of Work Available

RDF & XML Views

Cooked into CrossRef schema

YADS – A Description Service (1)

Open Data Model for Digital Objects

Manages Resource Hierarchies

Simple Generic XML Format

Provides (Latent) RDF Profile

Core Property Set

Extensible Typing

YADS – A Description Service (2)

Early API – Java , Perl , Python , Ruby

Library Code & XSLT Stylesheets

Serializations

YADS/XML (Generic)

RDF/XML

D (Text Description)

SVG

*(SRX - SPARQL)

*(YAML)

*(JSON)

YADS – Use Cases

Co-Hosting: Platforms, Mirror Sites

Multi-Homing: Products, Components

Rendering: Formats

Versioning: Editions

Significant “ Others ” : Errata, Suppl. Material, Etc

Service Acquisition: Metadata, Etc

YADS Model Walkthrough

YADS – Background

Origins Late ‘01 from Early Work on DOI

Focus on Multiple Resolution

Dealt with Task of Relating Handle Values

Resources

Literals

& Groups

Introduced Notion of a Handle “ Map ”

Subsequently Generalized to Model Any Web-Based Resource

YADS – Model Walkthrough

DOI Uses Handle Directory Service

DOI Single Resolution

Simple Redirect Service

DOI Multiple Resolution

Complex Service Set

Requires Resource Selection

Requires Resource Semantics

YADS Data Model

Manages & Describes Resource Hierarchy

YADS – Single Resource

YADS – Multiple Resources

YADS – Groups

YADS – Containers

YADS – Hierarchy

YADS – Profiles

YADS Defining the Model

YADS – Schemas

EBNF

RDF

RDFS

N3

OWL (DAML+OIL)

XML

DTD

XSD

RELAX NG

(Schematron, XCSL, XMI, …)

YADS – EBNF yads = { ( item | nest ) } ; (* Structural elements for aggregating resources & properties *) item = {property}, ( resource | collection ), {property} ; nest = ( {property}, resource, {property}, collection, {property} ) | ( {property}, collection, {property}, resource, {property} ) ; (* Structural element for aggregating structural elements *) collection = group, {group} ; group = item | nest ; (* Resource element as per RFC 3986. *) resource = any-uri ; (* Property elements attributing metadata to resources. *) property = access | detail | directive | label | role | service | type ;

YADS – RDF/N3 @prefix : <#> . @prefix s: <http://www.w3.org/2000/01/rdf-schema> . # Nest class ( :collection & :resource ) :Nest a s:Class . # Item class ( :collection | :resource ) :Item a s:Class . # Resource properties :collection a s:Property ; s:domain :Item, :Nest ; s:range s:Container . :resource a s:Property ; s:domain :Item, :Nest ; s:range s:Resource . # Application properties :access a s:Property ; s:domain :Item, :Nest ; s:range s:Literal . ...

YADS – XSD <xsd:element name = "yads"> <xsd:simpleType> <xsd:choice> <xsd:element ref = "item" minOccurs = "0" maxOccurs = "unbounded"/> <xsd:element ref = "nest" minOccurs = "0" maxOccurs = "unbounded"/> </xsd:choice> </xsd:simpleType> </xsd:element> <xsd:element name = "item"> <xsd:complexType> <xsd:sequence> <xsd:choice> <xsd:element ref = "collection"/> <xsd:element ref = "resource"/> </xsd:choice> <xsd:element ref = "property” minOccurs = "0" maxOccurs = "unbounded"/> </xsd:sequence> </xsd:complexType> </xsd:element> ...

YADS Serializing the Model

YADS – Example Object

YADS – Description doi:1014/waterloo_&_city_line ( # Line branches on line { ( # Line stations on line branch { ( resource => < doi:1014/tube/waterloo > type => " tube:station " access => " Rail Link " ) ( resource => < doi:1014/tube/bank > type => " tube:station " ) } type => " tube:line-branch " ) } type => " tube:line " )

YADS – Handle “Map” doi:1014/waterloo_&_city_line INDEX TYPE VALUE 0 map "( { ( { ( 1 2 3 ) ( 4 5 ) } 6 ) } 7 ) " 1 resource < doi:1014/tube/waterloo > 2 type " tube:station " 3 access " Rail Link " 4 resource < doi:1014/tube/bank > 5 type " tube:station " 6 type " tube:line-branch " 7 type " tube:line ”

YADS – YAML doi:1014/waterloo_&_city_line --- - # Line branches on line - - # Line stations on line branch - - resource: doi:1014/tube/waterloo type: tube:station access: Rail Link - resource: doi:1014/tube/bank type: tube:station - type: tube:line-branch - type: tube:line ...

YADS – Generic XML doi:1014/waterloo_&_city_line <item> <container> <item> <container> <item> <resource> doi:1014/tube/waterloo </resource> <property type="type"> tube:station </property> <property type="access"> Rail Link </property> </item> <item> <resource> doi:1014/tube/bank </resource> <property type="type"> tube:station </property> </item> </container> <property type="type"> tube:line-branch </property> </item> </container> <property type="type"> tube:line </property> </item>

YADS – Specific XML doi:1014/waterloo_&_city_line # Resources elements are promoted to group level # and are "attributed" with properties <resource type=" tube:line "> <resource type=" tube:line-branch "> <resource type=" tube:station " access=" Rail Link "> doi:1014/tube/waterloo </resource> <resource type=" tube:station "> doi:1014/tube/bank </resource> </resource> </resource>

YADS – Application XML (1) doi:1014/waterloo_&_city_line # Typed resources are named <tube:line> <tube:line-branch> <tube:station access="Rail Link">doi:1014/tube/waterloo </tube:station> <tube:station>doi:1014/tube/bank</tube:station> </tube:line-branch> </tube:line>

YADS – Application XML (2) doi:1014/menu_popup # Application XML instance: Menu Popup <menu label="Further Links"> <menu label="DOI Sites"> <item label="IDF">http://www.doi.org</data> <item label="CNRI">http://www.cnri.reston.va.us</data> </menu> </menu>

YADS – Schemas

EBNF

RDF

RDFS

N3

OWL (DAML+OIL)

XML

DTD

XSD

RELAX NG

(Schematron, XCSL, XMI, …)

YADS Querying the Model

YADS – Querying

Standard Query Languages

RDF by SPARQL

(XML by XQuery?)

Native Query Facilities

API

YADS – SPARQL Query BASE <file:../lib/doi/rdf/format1.rdf> PREFIX yads: <doi:1014/yads-schema-2002-04-03#> SELECT ?s ?p ?o WHERE { ?s ?p ?o }

YADS – SPARQL Results <?xml version="1.0" encoding="utf-8"?> <sparql xmlns="http://www.w3.org/2005/sparql-results#"> <head> <variable name="s"/> <variable name="p"/> <variable name="o"/> </head> <results ordered="false" distinct="false"> <result> <binding name="s"><uri> file:../lib/doi/rdf/format1.rdf </uri></binding> <binding name="p"><uri> doi:1014/yads-schema-2002-04-03#collection </uri></binding> <binding name="o"><bnode> r1167855627r26072r1 </bnode></binding> </result> <result> <binding name="s"><bnode> r1167855627r26072r5 </bnode></binding> <binding name="p"><uri> http://www.w3.org/1999/02/22-rdf-syntax-ns#_1 </uri></binding> <binding name="o"><bnode> r1167855627r26072r6 </bnode></binding> </result> ...

YADS Servicing the Model

YADS – Services

YADS Applying the Model

YADS – Home Page

YADS http://nurture.nature.com/tony/yads