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| Line 8: |
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| | * The value of a [[ContextId Data Range]] MUST conform to the ABNF defined below | | * The value of a [[ContextId Data Range]] MUST conform to the ABNF defined below |
| | | | |
| − | == Syntax == | + | == Definition == |
| − | The following [http://en.wikipedia.org/wiki/Augmented_Backus-Naur_form ABNF] defines a Higgins [[ContextId]]. All 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]) except:
| + | * An [[Context UDI]] is defined in [http://www.parity.com/spec/udi/udi-syntax.html UDI Syntax] |
| − | * '''xri2-authority''' and '''xri2-subseg''' are the '''xri-authority''' and '''xri-subset''' rules defined in the [http://wiki.oasis-open.org/xri/XriCd02/Xri2dot0Abnf ABNF for XRI 2.0] | + | |
| − | * '''xri3-authority''' and '''xri3-subseg''' are the '''xri-authority''' and '''xri-subset''' rules defined in the [http://wiki.oasis-open.org/xri/XriThree/SyntaxAbnf proposed ABNF for XRI 3.0]
| + | |
| − | | + | |
| − | <pre>
| + | |
| − | contextId_Data_Range = contextURI / contextXRI
| + | |
| − | | + | |
| − | contextURI = contextfileURI / contexthttpURI
| + | |
| − | contextfileURI = [ "file://" ] ipath-abempty descriptor-ext
| + | |
| − | descriptor-ext = ".xrds" / ".xdi" ;see note 1
| + | |
| − | contexthttpURI = ( "http://" / "https://" ) iauthority
| + | |
| − | ipath-abempty [ descriptor-ext ] [ "?" iquery ]
| + | |
| − | | + | |
| − | contextXRI = contextQXRI / ;see note 2
| + | |
| − | contextHXRI ;see note 3
| + | |
| − | contextQXRI = ( [ "xri://" ] xri2-contextQXRI ) /
| + | |
| − | ( [ "xri:" ] xri3-contextQXRI )
| + | |
| − | xri2-contextQXRI = xri2-authority [ "/($context)" *xri2-subseg ]
| + | |
| − | xri3-contextQXRI = xri3-authority [ "/$context" *xri3-subseg ]
| + | |
| − | contextHXRI = proxy-URI "/" (xri2-contextQXRI / xri3-contextQXRI )
| + | |
| − | proxy-URI = ( "http://" / "https://" ) proxy-reg-name
| + | |
| − | proxy-reg-name = "xri." ireg-name
| + | |
| − | </pre>
| + | |
| − | | + | |
| − | == Notes ==
| + | |
| − | | + | |
| − | # ".xrds" and ".xdi" are formats designed expressly for discovery and description of resources using HTTP(S) URIs and/or XRIs. XRDS format is defined by [http://www.oasis-open.org/committees/download.php/24286/xri-resolution-v2.0-wd-11-ed-02.doc XRI Resolution Working 2.0]. XDI format is being defined by the [http://www.oasis-open.org/committees/xdi OASIS XDI Technical Committee]. Other resource description file types can be supported by extending this ABNF rule.
| + | |
| − | # QXRI (Query XRI) is an XRI in URI-normal form without the "xri://" prefix (XRI 2.0) or "xri:" prefix (XRI 3.0). See Section 11.2 of [http://docs.oasis-open.org/xri/2.0/specs/cd02/xri-resolution-V2.0-cd-02.pdf XRI Resolution 2.0].
| + | |
| − | # HXRI (HTTP(S) XRI) is the format for encapsulating an XRI within an HTTP(S) URI for purposes of resolution by an XRI proxy resolver. See Section 6 of [http://docs.oasis-open.org/xri/2.0/specs/cd02/xri-resolution-V2.0-cd-02.pdf XRI Resolution 2.0].
| + | |
| − | | + | |
| − | == IdAS Related Nodes ==
| + | |
| − | * The Identity Attribute Service [[IdAS]] can be used as a service to access a Context given a ContextId.
| + | |
| − | * If two ContextId's values are equal, they refer to the same underlying Context, although not necessarily the same Context "container" instance returned by IdAS. This means that, as a requester of information, different clients of IdAS may see different subsets of the Context based on the authorization passed in during authentication.
| + | |
| − | == Examples ==
| + | |
| − | | + | |
| − | === contextURI ===
| + | |
| − | | + | |
| − | ==== contextfileURI ====
| + | |
| − | | + | |
| − | file://system/config/openid.xrds
| + | |
| − | file://system/config/openid.xdi
| + | |
| − | file://system/config/ldap.xrds
| + | |
| − | file://system/config/ldap.xdi
| + | |
| − | | + | |
| − | ==== contexthttpURI ====
| + | |
| − | | + | |
| − | http://example.com
| + | |
| − | https://example.com
| + | |
| − | http://example.com/user
| + | |
| − | https://example.com/user
| + | |
| − | http://example.com/higgins/openid.xrds
| + | |
| − | https://example.com/higgins/openid.xdi
| + | |
| − | http://example.com/higgins/ldap.xrds
| + | |
| − | https://example.com/higgins/ldap.xdi
| + | |
| − | | + | |
| − | === ContextQXRI ===
| + | |
| − | | + | |
| − | ==== contextQXRI – XRI 2.0 Form ====
| + | |
| − | | + | |
| − | =drummond
| + | |
| − | =drummond/($context)
| + | |
| − | =drummond/($context)*($openid)
| + | |
| − | =drummond/($context)*($ldap)
| + | |
| − | =!F83.62B1.44F.2813
| + | |
| − | =!F83.62B1.44F.2813/($context)*($openid)
| + | |
| − | =!F83.62B1.44F.2813/($context)*($ldap)
| + | |
| − | =drummond*mom
| + | |
| − | =drummond*mom/($context)*($openid)
| + | |
| − | =drummond*mom/($context)*($ldap)
| + | |
| − | @example
| + | |
| − | @example/($context)
| + | |
| − | @example/($context)*($openid)
| + | |
| − | @example/($context)*($ldap)
| + | |
| − | @free*example
| + | |
| − | @free*example/($context)*($openid)
| + | |
| − | @free*example/($context)*($ldap)
| + | |
| − | | + | |
| − | ==== contextQXRI – Proposed XRI 3.0 Form ====
| + | |
| − | | + | |
| − | =drummond
| + | |
| − | =drummond/$context
| + | |
| − | =drummond/$context$openid
| + | |
| − | =drummond/$context$ldap
| + | |
| − | =!F83.62B1.44F.2813
| + | |
| − | =!F83.62B1.44F.2813/$context$openid
| + | |
| − | =!F83.62B1.44F.2813/$context$$ldap
| + | |
| − | =drummond*mom
| + | |
| − | =drummond*mom/$context$openid
| + | |
| − | =drummond*mom/$context$ldap
| + | |
| − | @example
| + | |
| − | @example/$context
| + | |
| − | @example/$context$openid
| + | |
| − | @example/$context$ldap
| + | |
| − | @free*example
| + | |
| − | @free*example/$context$openid
| + | |
| − | @free*example/$context$ldap
| + | |
| − | | + | |
| − | === contextHXRI ===
| + | |
| − | A contextHXRI is a ContextQXRI that uses an HXRI proxy resolver prefix. "xri.net" is a public HXRI proxy resolver operated by XDI.org. All others are examples.
| + | |
| − | | + | |
| − | ==== contextHXRI – XRI 2.0 Form ====
| + | |
| − | | + | |
| − | http://xri.net/=drummond
| + | |
| − | http://xri.net/=drummond/($context)
| + | |
| − | https://xri.net/=drummond/($context)*($openid)
| + | |
| − | https://xri.net/=drummond*mom/($context)*($openid)
| + | |
| − | http://xri.example.com/@example/($context)*($openid)
| + | |
| − | http://xri.example.com/@free*example/($context)*($openid)
| + | |
| − | https://xri.example.org/@1000.a1b2.c3d4.9999!1234/($context)*($ldap)
| + | |
| − | | + | |
| − | ==== contextHXRI – Proposed XRI 3.0 Form ====
| + | |
| − | | + | |
| − | http://xri.net/=drummond
| + | |
| − | http://xri.net/=drummond/$context
| + | |
| − | https://xri.net/=drummond/$context$openid
| + | |
| − | https://xri.net/=drummond*mom/$context$openid
| + | |
| − | http://xri.example.com/@example/$context$openid
| + | |
| − | http://xri.example.com/@example*free/$context$openid
| + | |
| − | https://xri.example.org/@1000.a1b2.c3d4.9999!1234/$context$ldap
| + | |
| − | | + | |
| − | == Context Discovery Rules ==
| + | |
| − | A key property of a [[ContextId]] is that it can be resolved into the metadata necessary open a [[Context]]. The complete process for doing this is described in [[Context Discovery]]. Following are the discovery rules that apply to each form of ContextId.
| + | |
| − | | + | |
| − | === contextURI Discovery ===
| + | |
| − | Since URIs do not offer the structured identifier features of XRIs, they must resolve directly to an XRDS or XDI document containing the Higgins context configuration metadata for a specific context type.
| + | |
| − | | + | |
| − | ==== contextfileURI ====
| + | |
| − | # Open the identified file.
| + | |
| − | # For an XRDS file, select the highest priority service endpoint that conforms to the [[Higgins XRDS Service Endpoint]] requirements.
| + | |
| − | # For an XDI X3 file, parse the Higgins context configuration metadata from the X3 document as described in [[Higgins XDI Context Descriptor]].
| + | |
| − | | + | |
| − | ==== contexthttpURI ====
| + | |
| − | # Resolve the URI to a discovery document as specified in Section 6 of [http://docs.oasis-open.org/xri/2.0/specs/cd02/xri-resolution-V2.0-cd-02.pdf XRI Resolution 2.0].
| + | |
| − | ## If the contexthttpURI ends in the context descriptor extension '''.xrds''' for an XRDS document, use the MIME type '''application/xrds+xml'''.
| + | |
| − | ## If the contexthttpURI ends in the context descriptor extension '''.xdi''' for an XDI document, use the MIME type '''text/x3'''.
| + | |
| − | ## If the contexthttpURI does not end in a context descriptor extension, use either or both of these MIME types as preferred in content negotiation with the server.
| + | |
| − | # If the MIME type of the discovery document is '''application/xrds+xml''', select the highest priority service endpoint that conforms to the [[Higgins XRDS Service Endpoint]] requirements.
| + | |
| − | # If the MIME type is '''text/x3''', parse the Higgins context configuration metadata from the X3 document as described in [[Higgins XDI Context Descriptor]].
| + | |
| − | | + | |
| − | === contextXRI Discovery ===
| + | |
| − | Since XRIs are abstract structured identifiers intended designed explicitly for resource discovery and description, they offer more flexiblity in the discovery process.
| + | |
| − | | + | |
| − | ==== Using XRDS ====
| + | |
| − | # Resolve the authority component of the XRI as specified in [http://docs.oasis-open.org/xri/2.0/specs/cd02/xri-resolution-V2.0-cd-02.pdf XRI Resolution 2.0]. Trusted resolution is RECOMMENDED.
| + | |
| − | # From this XRDS document, select the [[Higgins XRDS Service Endpoint]] as defined in Section 13 of [http://docs.oasis-open.org/xri/2.0/specs/cd02/xri-resolution-V2.0-cd-02.pdf XRI Resolution 2.0]. Note that this provides a number of ways for ContextXRI authors to control service endpoint selection. Using the path component of the XRI to match a [[Higgins XRDS Service Endpoint]] is RECOMMENDED.
| + | |
| − | # Parse the Higgins context metadata as defined in [[Higgins XRDS Service Endpoint]].
| + | |
| − | | + | |
| − | ==== Using XDI ====
| + | |
| − | # Resolution of the authority component of the XRI may use either XRDS resolution or XDI context discovery.
| + | |
| − | ## For XRDS resolution, follow the same steps as described above, except that in the final XRDS document, the highest priority SEP of type '''xri://$xdi''' MUST be selected, and an XDI X3 document MUST be requested from that service endpoint URI.
| + | |
| − | ## For XDI context discovery, resolve the authority component of the XRI as specified in the XDI Contexts section of [http://wiki.oasis-open.org/xdi/XdiRdfModel XDI RDF Model]] document.
| + | |
| − | # In both cases, from the final XDI document, parse the XDI context description as defined in [[Higgins XDI Context Descriptor]].
| + | |
| | | | |
| | == Relationship to OpenID == | | == Relationship to OpenID == |
The only caveat to keep in mind is that if an OpenID 2.0 URL is used as a Higgins ContextId, the XRDS or XDI document to which it resolves must EITHER contain:
