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Difference between revisions of "Node Relation"
| Line 1: | Line 1: | ||
==Definition== | ==Definition== | ||
| − | * | + | * An [[EntityId]] is a kind of [[Attribute]] |
| − | * Each value of a [[ | + | * Each value of a [[EntityId]] is a URI(s) that identifies an [[Entity]] |
== Details == | == Details == | ||
| − | Note: If the two [[Entity | Entities]] being linked are digital representations of the same person, thing or concept then a specialization of [[ | + | Note: If the two [[Entity | Entities]] being linked are digital representations of the same person, thing or concept then a specialization of [[EntityId]] called a [[Correlation]] should be used. |
==Format== | ==Format== | ||
A [[Relation]] is a URI. It is comprised of a [[ContextId]] URI combined with an optional identifier string called a [[LocalId]]. The [[LocalId]] may only be omitted when the [[Context]] identified by the [[ContextId]] contains exactly one [[Entity]]. | A [[Relation]] is a URI. It is comprised of a [[ContextId]] URI combined with an optional identifier string called a [[LocalId]]. The [[LocalId]] may only be omitted when the [[Context]] identified by the [[ContextId]] contains exactly one [[Entity]]. | ||
| − | Two kinds of [[ | + | Two kinds of [[EntityId]s are defined: a URIrelation (Hash URI) and XRIrelation. The former is consistent with one of the two proposed W3C's [http://www.w3.org/TR/2007/WD-cooluris-20071217/ Cool URIs] approaches. The latter is an [http://en.wikipedia.org/wiki/XRI XRI] as defined by [http://wiki.oasis-open.org/xri/XriCd02/Xri2dot0Abnf XRI Syntax 2.0]. |
=== ABNF === | === ABNF === | ||
| − | The following [http://en.wikipedia.org/wiki/Augmented_Backus-Naur_form ABNF] defines a Higgins [[ | + | The following [http://en.wikipedia.org/wiki/Augmented_Backus-Naur_form ABNF] defines a Higgins [[EntityId]. Rules not defined in this ABNF are defined in the [http://wiki.oasis-open.org/xri/XriCd02/Xri2dot0Abnf ABNF for XRI 2.0] (which includes the IRI ABNF from [http://www.ietf.org/rfc/rfc3987.txt RFC 3987]). |
relation = URIrelation / XRIrelation | relation = URIrelation / XRIrelation | ||
Revision as of 19:49, 31 January 2008
Contents
Definition
Details
Note: If the two Entities being linked are digital representations of the same person, thing or concept then a specialization of EntityId called a Correlation should be used.
Format
A Relation is a URI. It is comprised of a ContextId URI combined with an optional identifier string called a LocalId. The LocalId may only be omitted when the Context identified by the ContextId contains exactly one Entity.
Two kinds of [[EntityId]s are defined: a URIrelation (Hash URI) and XRIrelation. The former is consistent with one of the two proposed W3C's Cool URIs approaches. The latter is an XRI as defined by XRI Syntax 2.0.
ABNF
The following ABNF defines a Higgins [[EntityId]. Rules not defined in this ABNF are defined in the ABNF for XRI 2.0 (which includes the IRI ABNF from RFC 3987).
relation = URIrelation / XRIrelation URIrelation = contextURI [ "#" subjectId ] XRIrelation = contextXRI [ "//" subjectId ]
Relationship to OpenID
- A Relation's ContextId MAY use OpenID (2.0 only) for its authority segment. See ContextId for details.
Open Issues
- Should we allow the ContextId to be omitted if a LocalId is present? (saves repeating the ContextId when referring to another Entity in the same Context