Internet DRAFT - draft-ietf-calext-icalendar-jscalendar-extensions
draft-ietf-calext-icalendar-jscalendar-extensions
Calendaring Extensions R. Stepanek
Internet-Draft FastMail
Intended status: Standards Track M. Douglass
Expires: 12 January 2023 BCS
11 July 2022
iCalendar Format Extension for JSCalendar
draft-ietf-calext-icalendar-jscalendar-extensions-00
Abstract
This document defines a set of new properties for iCalendar and
extends the use of existing ones. Their primary purpose is to align
the same set of features between the JSCalendar and iCalendar
formats, but the new definitions also aim to be useful within just
the iCalendar format.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 12 January 2023.
Copyright Notice
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Table of Contents
1. Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
3. New Properties . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. COMP-ID Property . . . . . . . . . . . . . . . . . . . . 3
3.2. SHOW-WITHOUT-TIME Property . . . . . . . . . . . . . . . 4
4. Updated Properties . . . . . . . . . . . . . . . . . . . . . 4
4.1. GEO Property . . . . . . . . . . . . . . . . . . . . . . 5
5. New Parameters . . . . . . . . . . . . . . . . . . . . . . . 5
5.1. CONTENT-ID Parameter . . . . . . . . . . . . . . . . . . 5
5.2. INVITED-BY Parameter . . . . . . . . . . . . . . . . . . 6
5.3. LINK-REL Parameter . . . . . . . . . . . . . . . . . . . 6
5.4. PROP-ID Parameter . . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Preface
This document is a work in progress. The list of new or updated
properties and parameters is likely to be incomplete. This section
is removed from the document before publication.
2. Introduction
The JSCalendar [RFC8984] format aims to be an alternative to the
iCalendar [RFC5545] format for representation of calendar data. As
such, it introduces new semantics that are not covered in the current
definition of iCalendar and its extensions. Converting calendar data
between the two formats is defined in [ref-jscalendar-icalendar] with
the goal of not loosing any semantics during conversion. In order to
do so, this document defines a new set of properties for iCalendar
and extends existing definitions.
2.1. 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 BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
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3. New Properties
3.1. COMP-ID Property
Property name: COMP-ID
Purpose: This property uniquely identifies a component among all its
siblings of the same type.
Value type: TEXT, also see Format Definition for value restrictions.
Conformance: The property can be specified once in a calendar
component.
Property parameters: IANA and non-standard property parameters can
be specified on this property.
Description: A calendar component may embed multiple components of
the same type. For example, a VEVENT component may embed multiple
VALARM components. To distinguish these VALARMs among all global
instances of VALARM calendar components, an application may choose
to assign a uniquely global UID to each of them. However, some
applications or formats such as JSCalendar, do not require
globally uniqueness. Instead, they only require uniqueness among
all instances of calendar components within one parent component.
This is what the COMP-ID property is for.
The COMP-ID property identifies a component among all of its
siblings of the same type. A valid COMP-ID value must be of 1 and
a maximum of 255 octets in size, and it MUST only contain the
ASCII alphanumeric characters (A-Za-z0-9), hyphen (-), and
underscore (_). The identifier only has the purpose to uniquely
identify siblings, its value has no other meaning. If an
application makes use of COMP-ID it SHOULD assign a unique
identifier to each sibling component of the same type within their
parent component. The same identifier MAY be used for components
of a different type, and it MAY also be assigned to a same-typed
component that is not a sibling.
Resolving duplicate identifier conflicts is specific to the
application. Similarly, handling components where some but not
all siblings have a COMP-ID is assigned, is application-specific.
Format definition: This property is defined by the following
notation:
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comp-id = "COMP-ID" comp-id-param ":" comp-id-value CRLF
comp-id-value = 1*255(ALPHA / DIGIT / "-"/ "_")
comp-id-param = *(";" other-param)
Example(s):
COMP-ID:m2398
3.2. SHOW-WITHOUT-TIME Property
Property name: SHOW-WITHOUT-TIME
Purpose: This property indicates if an event or task should be
displayed with time information.
Value type: BOOLEAN
Conformance: The property can be specified once in the VEVENT, VTODO
or VJOURNAL calendar components.
Property parameters: IANA and non-standard property parameters can
be specified on this property.
Description: This indicates that the time is not important to
display to the user when rendering this calendar object. An
example of this is an event that conceptually occurs all day or
across multiple days, such as "New Year's Day" or "Italy
Vacation". While the time component is important for free-busy
calculations and checking for scheduling clashes, calendars may
choose to omit displaying it and/or display the object separately
to other objects to enhance the user's view of their schedule.
Format definition: This property is defined by the following
notation:
show-without-time = "SHOW-WITHOUT-TIME" show-without-time-param
":" boolean CRLF
show-without-time-param = *(";" other-param)
Example(s):
SHOW-WITHOUT-TIME:TRUE
4. Updated Properties
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4.1. GEO Property
This specification modifies the definition of the GEO property to
allow storing spatial positions in form of URIs using the geo: scheme
[RFC5870]. The following additions are made to the definition of
this property, original specified in Section 3.8.1.6 of [RFC5545].
Value type: The default value type is FLOAT, where the value MUST be
two SEMICOLON-separated FLOAT values. The value type can also be
set to URI to indicate geo: encoded coordinates.
Property parameters: VALUE
Description: When the property value is a URI in the geo: scheme,
then the VALUE property parameter MUST be set to URI.
Format definition: This property is defined by the following
notation:
geo = "GEO" geoparam ( ":" geovalue ) /
(
";" "VALUE" "=" "URI"
":" uri ; uri MUST be in the geo: scheme
)
CRLF
geoparam = *(";" other-param)
geovalue = float ";" float
;Latitude and Longitude components
Example(s):
GEO:37.386013;-122.082932
GEO;VALUE=URI:geo:48.198634,16.371648;crs=wgs84;u=40
5. New Parameters
5.1. CONTENT-ID Parameter
Parameter name: CONTENT-ID
Purpose: This parameter identifies an attachment contents for use
with styled descriptions.
Format definition:
cid-param = "CONTENT-ID" "=" DQUOTE uri DQUOTE
; uri must be a cid-url defined in RFC 8288
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Description: This parameter MAY be set on an "ATTACH" or "IMAGE"
property. It assigns the property an identifier that MUST be
unique within the calendar component. A calendar component MAY
include a STYLED-DESCRIPTION property as specified in Section 6.5
of [RFC9073], and MAY contain HTML text. URLs in the "cid:"
scheme referred to by images and other data within that HTML
description can be resolved to calendar component attachments
having that content-id.
Example(s):
IMAGE;CONTENT-ID="cid:foo@bar.net":
data:image/jpeg;base64,SGVsbG8sIFdvcmxk..
STYLED-DESCRIPTION;VALUE=TEXT;FMTTYPE=text/html:
<html><body><img src="cid:foo@bar.net" alt="foo"/></body></html>
5.2. INVITED-BY Parameter
Parameter name: INVITED-BY
Purpose: This parameter specifies which calendar address user
invited another.
Format definition:
inviteby-param = "INVITED-BY" "=" DQUOTE cal-address DQUOTE
Description: This parameter MAY be set on an "ATTENDEE" property,
specified in Section 3.8.4.1 of [RFC5545]. If set, it identifies
the participant that invited the calendar user represented by the
ATTENDEE property to the calendar component.
Example(s):
ATTENDEE;INVITED-BY="inviter@example.com":invitee@example.com
5.3. LINK-REL Parameter
Parameter name: LINK-REL
Purpose: This parameter defines how an attachment relates to
calendar component.
Format definition:
linkrel-param = "LINK-REL" "=" paramtext
; one of Link Relation Types registered in
; the IANA Link Relations Registry (RFC 8288)
Description: This parameter MAY be set on an "ATTACH" or "IMAGE"
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property. It indicates how the contents of the attachment or
image relate to the calendar component this property is part of.
For the list of available relations, see the Link Relation Types
in the IANA Link Relations Registry [RFC8288].
Example(s):
ATTACH;LINK-REL=payment:https://example.com/donate
5.4. PROP-ID Parameter
Parameter name: PROP-ID
Purpose: This parameter identifies a property among all its siblings
of the same type.
Format definition:
prop-id-param = "PROP-ID" "=" 1*255(ALPHA / DIGIT / "-"/ "_")
Description: This parameter uniquely identifies a property among all
of its siblings with the same name within a calendar component. A
valid PROP-ID value must be of 1 and a maximum of 255 octets in
size, and it MUST only contain the ASCII alphanumeric characters
(A-Za-z0-9), hyphen (-), and underscore (_). The identifier only
has the purpose to uniquely identify siblings, its value has no
other meaning. If an application makes use of PROP-ID it SHOULD
assign a unique identifier to each sibling property of the same
name within their embedding component. The same identifier MAY be
used for properties of a different name, and it MAY also be
assigned to a same-named property that is not a sibling.
Resolving duplicate identifier conflicts is specific to the
application. Similarly, handling properties where some but not
all siblings have a PROP-ID is assigned, is application-specific.
Example(s):
ATTACH;PROP-ID=a983:https://example.com/something
6. IANA Considerations
This section will be filled at a later stage.
7. Security Considerations
This section will be filled at a later stage.
8. References
8.1. Normative References
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and
Scheduling Core Object Specification (iCalendar)",
RFC 5545, DOI 10.17487/RFC5545, September 2009,
<https://www.rfc-editor.org/info/rfc5545>.
[RFC5870] Mayrhofer, A. and C. Spanring, "A Uniform Resource
Identifier for Geographic Locations ('geo' URI)",
RFC 5870, DOI 10.17487/RFC5870, June 2010,
<https://www.rfc-editor.org/info/rfc5870>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8288] Nottingham, M., "Web Linking", RFC 8288,
DOI 10.17487/RFC8288, October 2017,
<https://www.rfc-editor.org/info/rfc8288>.
[RFC8984] Jenkins, N. and R. Stepanek, "JSCalendar: A JSON
Representation of Calendar Data", RFC 8984,
DOI 10.17487/RFC8984, July 2021,
<https://www.rfc-editor.org/info/rfc8984>.
[RFC9073] Douglass, M., "Event Publishing Extensions to iCalendar",
RFC 9073, DOI 10.17487/RFC9073, August 2021,
<https://www.rfc-editor.org/info/rfc9073>.
8.2. Informative References
[ref-jscalendar-icalendar]
"JSCalendar: Converting from and to iCalendar",
<https://datatracker.ietf.org/doc/draft-ietf-calext-
jscalendar-icalendar/>.
Authors' Addresses
Robert Stepanek
FastMail
PO Box 234, Collins St West
Melbourne VIC 8007
Australia
Email: rsto@fastmailteam.com
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Michael Douglass
Bedework Commercial Services
226 3rd Street
Troy, NY 12180
United States of America
Email: mdouglass@bedework.com
URI: http://bedework.com
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