XDI Graph Patterns

1. This document contains illustrations of seven basic XDI graph patterns: Simple properties: properties that accept only a single literal value. Complex properties: properties that may accept multiple literal values as well as describe typing and ordering of those values. Simple subjects: subjects that may contain only instances of themselves and metadata describing those instances. Complex subjects: subjects that may contain all of the above. Social graphs: relationships between XDI authorities. Link contracts: subgraphs used for XDI authorization. Messages: XDI documents used in the XDI protocol. It also illustrates how versioning may be applied to any branch of the graph. Note: this document uses the XDI metagraph symbols as documented in the XDI Graph Model 2011-02-09. XDI Graph Patterns OASIS XDI TC SubmissionDrummond Reed 2011-02-18

2. Notation Root node: Represents the root context of an XDI graph Context node: Represents an XDI subject or non-literal XDI object Literal node: Represents a literal XDI object Contextual arc: Uniquely identifies a context node Literal arc: Uniquely identifies a literal node Relational arc: Non-uniquely links nodes Example root context literal “literal” contextual context literal contextual “literal” context contextual relational context

3. Simple properties (=abc) (=abc) =abc =abc +age! =abc/+age! “33” Simple property graph +age =abc+age Metadata subgraphfpr +age simple property =abc+age/$d! $d! “2010-10-10T11:12:13Z” Versioning metadata subgraph $v =abc+age$v =abc+age$v/!1! !1! “32” First version value =abc+age$v/!2! !2! “33” Second version value !1 =abc+age$v!1 First version datestamp $d! =abc+age$v!1/$d! “2010-09-09T10:11:12Z” !2 =abc+age$v!2 Second version datestamp $d! =abc+age$v!2/$d! “2010-10-10T11:12:13Z”

4. Complex properties (=abc) +home+fax +home =abc+tel/+home+fax =abc+tel/+home =abc+tel/*2 =abc+tel/!1! (=abc) =abc *2 =abc !1! +tel “+1.206.555.1111” !2! =abc+tel “+1.206.555.2222” *1 =abc+tel/!2! =abc+tel/*1 =abc+tel/+work +work Complex property graph Metadata subgraphs for +tel complex property !1 =abc+tel!1 $d! =abc+tel!1/$d! “2010-11-11T11:11:11Z” !2 =abc+tel!2 $d! =abc+tel!2/$d! “2010-12-22T22:22:22Z” Versioning metadata subgraph $v =abc+tel$v !1 =abc+tel$v!1 First version snapshot(subgraph not shown) … !2 =abc+tel$v!2 Second version shapshot(subgraph not shown) …

5. Simple subjects (=abc) =abc+passport!1/+country! +country! “Canada” (=abc) =abc+passport!1 =abc+passport!1/+number! +number! !1 =abc =abc “987654321” $d! =abc+passport!1/+$d! +passport *1 “2005-01-01T00:00:00Z” =abc+passport!2/+country! =abc+passport +country! *2 “New Zealand” !2 =abc+passport!2/+number! +number! “123456789” $d! =abc+passport!2 =abc+passport!2/+$d! “2010-10-01T00:00:00Z” Simple subject graph Metadata subgraph for +passport simple subject () =abc+passport() !1 =abc+passport()!1 $d! =abc+passport()!1/$d! “2010-11-11T11:11:11Z” !2 =abc+passport()!2 $d! =abc+passport()!2/$d! “2010-12-22T22:22:22Z” Versioning metadata subgraph $v =abc+tel$v !1 =abc+tel$v!1 First version snapshot(subgraph not shown) … !2 =abc+tel$v!2 Second version shapshot(subgraph not shown) …

6. Complex subjects (=abc) =abc/+age! +age! “33” (=abc) =abc Examples of from previous pages (child subgraphs not shown) of attributes of the complex subject =abc =abc+tel +tel =abc … +passport =abc+passport … !1 Subgraphs for instances of the =abc complex subject (child subgraphs not shown) =abc!1 … !2 =abc!2 For a person, these would be “personas” … Metadata subgraph for =abc complex subject () =abc() !1 =abc()!1 $d! =abc()!1/$d! !2 “2010-11-11T11:11:11Z” =abc()!2 $d! =abc()!2/$d! “2010-12-22T22:22:22Z” Versioning metadata subgraph $v =abc$v !1 =abc$v!1 First version snapshot(subgraph not shown) … !2 =abc$v!2 Second version shapshot(subgraph not shown) …

7. Social graphs (=abc) Social graph expressed at the =abc endpoint (=abc) =abc =abc =xyz =abc is best friends with =xyz +best+friend =xyz (http://facebook.com) (http://facebook.com) =abc is friends with =xyz in the Facebook context +friend =xyz (http://facebook.com)=xyz +seattle +seattle +soccer =abc is a teammate of =xyz in a Seattle soccer context +seattle+soccer +teammate =xyz +seattle+soccer=xyz

8. Link contracts (=abc) +age! =abc/+age! “33” (=abc) =abc +tel =abc+tel =abc +passport =abc+passport +age! =abc!1/+age! Subgraph of =abc properties included in personal =abc!1 !1 +tel =abc!1 =abc!1/+tel Link contract $do =abc!1$do Link contract root node $get =abc!1$do$get (=xyz) … $() Permitted XDI operations on the =abc!1 graph (subtrees not shown) (=xyz) $add … Link contract assignment =abc!1$do$add $for =abc!1$do$for … Policies under which these permissions are granted

9. Messages (=abc) “from” – source endpoint (=abc) $msg Message context $msg !1234 Message ID $msg!1234 (=xyz) Datestamp $() $d! $msg!1234/$d! (=xyz) “2010-12-22T22:22:22Z” “to” – target endpoint(s) Message envelope Message actions $do $msg!1234$do Message action root $get $msg!1234$do$get … Message actions (verbs and subgraphs must match link contracts) (subgraphs not shown) $add … $msg!1234$do$add $for $msg!1234$do$for … Optional description of the message purpose (must match link contract) (subgraph not shown)