GeoJSON S. Gillies Internet-Draft Mapbox Intended status: Informational September 9, 2016 Expires: March 13, 2017 GeoJSON Text Sequences draft-ietf-geojson-text-sequence-01 Abstract A proposed standard for geographic data that can be parsed and produced incrementally. Status of This Memo 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 http://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 March 13, 2017. Copyright Notice Copyright (c) 2016 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 (http://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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Gillies Expires March 13, 2017 [Page 1] Internet-Draft GeoJSONSeq September 2016 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. GeoJSON Text Sequence Format . . . . . . . . . . . . . . . . 2 3. Security Considerations . . . . . . . . . . . . . . . . . . . 3 4. Interoperability Considerations . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 4 Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction Large or never-ending sequences of records pose a problem for JSON that is well explained in the motivation for JSON Text Sequences [RFC7464]. GeoJSON [RFC7946] faces the same kind of problem: geographic datasets often run to the tens of thousands or millions of features. The problem is often amplified by the prescence of large arrays of coordinates for each of the features. This document describes a specialization of JSON Text Sequences. A GeoJSON Text Sequence is a document of possibly infinite size containing one or more GeoJSON objects, e.g., multiple GeoJSON texts that can be parsed and produced incrementally, and not only a single GeoJSON FeatureCollection, Feature, or Geometry. The advantage of using ASCII character RS "0x1e" to denote a record is that sequence producers and parsers need not enforce a canonical form for record GeoJSON. Any valid GeoJSON, pretty-printed or compact, can be used in a GeoJSON text sequence. Additionally, GeoJSON text sequences inherit from the other [RFC7464] rules for consistent processing of sequences with potentially corrupted records. 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. GeoJSON Text Sequence Format Defined in prose, following [RFC7464]: a GeoJSON text sequence is any number of GeoJSON [RFC7946] texts, each encoded in UTF-8 [RFC3629], each preceded by one ASCII RS character, and each followed by a line feed (LF). Gillies Expires March 13, 2017 [Page 2] Internet-Draft GeoJSONSeq September 2016 The GeoJSON Text Sequence Format conforms to all the rules of [RFC7464] and adds the following constraint: each JSON text MUST contain a single GeoJSON object as defined in [RFC7946]. Heterogeneous sequences containing a mix of GeoJSON Geometry, Feature, and FeatureCollection objects are permitted. How producers and parsers of GeoJSON text sequences communicate rules for allowed GeoJSON types in exchanged sequences is not specified in this document. 3. Security Considerations GeoJSON text sequences have no security considerations beyond those of JSON text sequences and the GeoJSON format. 4. Interoperability Considerations A variety of parsers designed for newline-delimited sequences of compact JSON text are deployed on the internet today. While there is no canonical form for JSON texts, and pretty-printed and compact forms are equally valid, GeoJSON text sequences containing compact GeoJSON texts with no internal newlines are more interoperable with existing non-standardized parsers. In a distributed system where order and exactly-once delivery of messages are difficult to achieve, GeoJSON text sequences that do not rely on order of texts for extra semantics are more interoperable than those that do. 5. IANA Considerations The MIME media type for GeoJSON feature sequences is application/ geo+json-seq. Type name: application Subtype name: geo+json-seq Required parameters: n/a Optional parameters: n/a Encoding considerations: binary Security considerations: See Section 3 above Interoperability considerations: See Section 4 abovee Gillies Expires March 13, 2017 [Page 3] Internet-Draft GeoJSONSeq September 2016 Published specification: [[This document]] Applications that use this media type: No known applications currently use this media type. This media type is intended for GeoJSON applications currently using colloquial line-delimited variants of GeoJSON. Additional information: Magic number(s): n/a File extension(s): n/a Macintosh file type code: n/a Object Identifiers: n/a Person to contact for further information: Sean Gillies (sean.gillies@gmail.com) Intended usage: COMMON Restrictions on usage: none 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November 2003, . [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data Interchange Format", RFC 7159, March 2014. [RFC7464] Williams, N., "JavaScript Object Notation (JSON) Text Sequences", RFC 7464, DOI 10.17487/RFC7464, February 2015, . [RFC7946] Butler, H., Daly, M., Doyle, A., Gillies, S., Hagen, S., and T. Schaub, "The GeoJSON Format", RFC 7946, DOI 10.17487/RFC7946, August 2016, . Gillies Expires March 13, 2017 [Page 4] Internet-Draft GeoJSONSeq September 2016 Appendix A. Contributors TODO. Author's Address S. Gillies Mapbox Email: sean.gillies@gmail.com URI: http://sgillies.net Gillies Expires March 13, 2017 [Page 5]