|Internet-Draft||sdfType for Links||December 2022|
|Bormann||Expires 4 June 2023||[Page]|
- ASDF WG
- Intended Status:
- Standards Track
An sdfType for Links
This document defines and registers an sdfType "link" for the Semantic Definition Format (SDF) for Data and Interactions of Things (draft-ietf-asdf-sdf-12.txt).¶
This note is to be removed before publishing as an RFC.¶
Status information for this document may be found at https://datatracker.ietf.org/doc/draft-bormann-asdf-sdftype-link/.¶
Discussion of this document takes place on the A Semantic Definition Format for Data and Interactions of Things Working Group mailing list (mailto:email@example.com), which is archived at https://mailarchive.ietf.org/arch/browse/asdf/. Subscribe at https://www.ietf.org/mailman/listinfo/asdf/.¶
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."¶
This Internet-Draft will expire on 4 June 2023.¶
Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
The Semantic Definition Format for Data and Interactions of Things (SDF, [I-D.ietf-asdf-sdf]) is a format for domain experts to use in the creation and maintenance of data and interaction models in the Internet of Things.¶
A common data type that occurs in the modeling of IoT devices is the link. [RFC8288] defines the concept of Web Linking, which complements the target URI that any link will contain, with additional parameters, such as the "link relation type" that explains the relationship expressed by the link, as well as "target attributes" that provide additional information about the target of the link (without a need to "dereference", i.e., follow, the link).¶
This document defines and registers an sdfType "link" for the Semantic Definition Format. This type models an abstract "serialization" [RFC8288] of a link, in a way that is compatible with the way SDF maps information models to its data modeling language.¶
Links play an important role in SDF modeling both during definition
time (for adding information to a model, as e.g., in
during run time (for making links to instances into a subject of data
and interaction modeling).
The present document is an early attempt at addressing the run-time
usage of links, in particular links that fit the Web Linking [RFC8288]
A related draft [I-D.laari-asdf-relations] addresses definition-time links, but does
seem to touch modeling run-time use of links as well (e.g., by
discussing "writable" link relations).¶
Not all links used in ecosystems are based on URIs.
E.g., OMA has "object links", which are pairs of numbers (object/instance).
These ecosystem links may have some structure that should be modeled
in the SDF model (e.g., where the object id part of a link always has
to have a specific value).
This structure can be mapped into URI strings using some convention,
e.g., an OMA object link could be
oma-object is placeholder for a URI scheme to be defined).
However, burying structural components of the ecosystem-specific link
in a string syntax makes it hard to access and control those
components from the model.¶
Examples are needed to show how the OCF collection pattern is addressed by the current specification.¶
The security considerations of [RFC8288] apply in a general way, although modeling a link as a datatype does not incur all of the security considerations that will apply to actually interchanging these links.¶
TODO: This document registers the sdfType "link" in the SDF sdfType registry (which is to be defined in the SDF specification).¶
- Koster, M. and C. Bormann, "Semantic Definition Format (SDF) for Data and Interactions of Things", Work in Progress, Internet-Draft, draft-ietf-asdf-sdf-12, , <https://www.ietf.org/archive/id/draft-ietf-asdf-sdf-12.txt>.
- Nottingham, M., "Web Linking", RFC 8288, DOI 10.17487/RFC8288, , <https://www.rfc-editor.org/info/rfc8288>.
- Bormann, C., "CoRE Target Attribute Registry", Work in Progress, Internet-Draft, draft-bormann-core-target-attr-01, , <https://www.ietf.org/archive/id/draft-bormann-core-target-attr-01.txt>.
- Laari, P., "Extended relation information for Semantic Definition Format (SDF)", Work in Progress, Internet-Draft, draft-laari-asdf-relations-00, , <https://www.ietf.org/archive/id/draft-laari-asdf-relations-00.txt>.
- Shelby, Z., "Constrained RESTful Environments (CoRE) Link Format", RFC 6690, DOI 10.17487/RFC6690, , <https://www.rfc-editor.org/info/rfc6690>.