ContextId

Introduction

This page describes and defines a Higgins ContextId.

Definition

• A ContextId is a kind of Context Correlation
• A ContextId identifies a instance of a Context
• A ContextId MUST have a single value of type ContextIdDatatype
• If a Context has a ContextId Attribute its value identifies the Context itself.

Details

• The value of a ContextId must directly or indirectly (e.g. by resolution) provide sufficient information to identify a Context. See the Context Discovery with a ContextId heading below.
• Two different ContextIds may refer to the same Context.

ContextId and IdAS

• 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 Digital Identities may see different subsets of the Context based on the authorization passed in during authentication.
• A given ContextId may be used against multiple Context Providers to produce the same Context (although, as mentioned, different Context instances).

Details

• The Identity Attribute Service (IdAS) can be used as a service to access a Context given a ContextId

Some ContextIds are not resolvable to a Context instance. Most Contexts are not abstract. Using a network (or local) data access service their ContextIds are resolvable to data objects that are instantiated and managed by Context Provider plug-ins.

Open Issues

1. Should the contextId ABNF support IRI (Internationalized Resource Identifiers) and not just URIs? Note that the ABNF above uses IRI rules; this needs to be changed if only URIs will be supported.

See Also

• EntityId
• LocalId
• Context Discovery
• Context Discovery Components
• Higgins XRDS Service Endpoint
• Higgins XDI Context Reference
• Concepts

Links

• Higgins Home