| Rfc | 7095 |
|---|
| Title | jCard: The JSON Format for vCard |
|---|
| Author | P. Kewisch |
|---|
| Date | January 2014 |
|---|
| Format: | TXT, HTML |
|---|
| Status: | PROPOSED STANDARD |
|---|
|
Internet Engineering Task Force (IETF) P. Kewisch
Request for Comments: 7095 Mozilla
Category: Standards Track January 2014
ISSN: 2070-1721
jCard: The JSON Format for vCard
Abstract
This specification defines "jCard", a JSON format for vCard data.
The vCard data format is a text format for representing and
exchanging information about individuals and other entities, for
example, telephone numbers, email addresses, structured names, and
delivery addresses. JSON is a lightweight, text-based, language-
independent data interchange format commonly used in Internet
applications.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7095.
Copyright Notice
Copyright (c) 2014 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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. Converting from vCard to jCard . . . . . . . . . . . . . . . 4
3.1. Pre-processing . . . . . . . . . . . . . . . . . . . . . 4
3.2. jCard Object and Syntactic Entities (RFC 6350, Sections
6.1.1 and 6.1.2) . . . . . . . . . . . . . . . . . . . . 5
3.3. Properties (RFC 6350, Section 6) . . . . . . . . . . . . 5
3.3.1. Special Cases for Properties . . . . . . . . . . . . 7
3.3.1.1. The VERSION Property . . . . . . . . . . . . . . 7
3.3.1.2. Grouping of Properties . . . . . . . . . . . . . 7
3.3.1.3. Structured Property Values . . . . . . . . . . . 8
3.4. Parameters (RFC 6350, Section 5) . . . . . . . . . . . . 10
3.4.1. VALUE Parameter . . . . . . . . . . . . . . . . . . . 10
3.4.2. Multi-Valued Parameters . . . . . . . . . . . . . . . 11
3.5. Values (RFC 6350, Section 4) . . . . . . . . . . . . . . 11
3.5.1. Text (RFC 6350, Section 4.1) . . . . . . . . . . . . 12
3.5.2. URI (RFC 6350, Section 4.2) . . . . . . . . . . . . . 12
3.5.3. Date (RFC 6350, Section 4.3.1) . . . . . . . . . . . 12
3.5.4. Time (RFC 6350, Section 4.3.2) . . . . . . . . . . . 13
3.5.5. Date-Time (RFC 6350, Section 4.3.3) . . . . . . . . . 14
3.5.6. Date and/or Time (RFC 6350, Section 4.3.4) . . . . . 16
3.5.7. Timestamp (RFC 6350, Section 4.3.5) . . . . . . . . . 16
3.5.8. Boolean (RFC 6350, Section 4.4) . . . . . . . . . . . 17
3.5.9. Integer (RFC 6350, Section 4.5) . . . . . . . . . . . 17
3.5.10. Float (RFC 6350, Section 4.6) . . . . . . . . . . . . 17
3.5.11. UTC Offset (RFC 6350, Section 4.7) . . . . . . . . . 18
3.5.12. Language Tag (RFC 6350, Section 4.8) . . . . . . . . 18
3.6. Extensions (RFC 6350, Section 6.10) . . . . . . . . . . . 18
4. Converting from jCard into vCard . . . . . . . . . . . . . . 19
5. Handling Unrecognized Properties or Parameters . . . . . . . 19
5.1. Converting vCard into jCard . . . . . . . . . . . . . . . 19
5.2. Converting jCard into vCard . . . . . . . . . . . . . . . 20
5.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . 20
6. Security Considerations . . . . . . . . . . . . . . . . . . . 21
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
7.1. GROUP vCard Parameter . . . . . . . . . . . . . . . . . . 23
7.2. UNKNOWN vCard Value Data Type . . . . . . . . . . . . . . 24
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 24
9.1. Normative References . . . . . . . . . . . . . . . . . . 24
9.2. Informative References . . . . . . . . . . . . . . . . . 25
Appendix A. ABNF Syntax . . . . . . . . . . . . . . . . . . . . 26
Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 27
B.1. Example: vCard of the Author of RFC 6350 . . . . . . . . 27
B.1.1. vCard Data . . . . . . . . . . . . . . . . . . . . . 27
B.1.2. jCard Data . . . . . . . . . . . . . . . . . . . . . 28
1. Introduction
The vCard data format [RFC6350] provides for the capture and exchange
of information normally stored within an address book or directory
application. The vCard format has gone through multiple revisions,
most recently vCard 4.
As certain similarities exist between vCard and the iCalendar data
format [RFC5545], there is also an effort to define a JSON-based data
format for calendar information called jCal [JCAL] that parallels the
format defined in this specification. The term "JSON" describes the
JavaScript Object Notation defined in [RFC4627].
The purpose of this specification is to define "jCard", a JSON format
for vCard data. One main advantage to using a JSON-based format over
the classic vCard format is easier processing for JavaScript-based
widgets and libraries, especially in the scope of web-based
applications.
The key design considerations are essentially the same as those for
[JCAL] and [RFC6321], that is:
Round-tripping (converting a vCard instance to jCard and back)
will give the same semantic result as the starting point. For
example, all components, properties, and property parameters are
guaranteed to be preserved.
The Ordering of elements and the case of property and parameter
names will not necessarily be preserved.
The vCard data semantics are to be preserved, allowing a simple
consumer to easily browse the data in jCard. A full understanding
of vCard is still required in order to modify and/or fully
comprehend the directory data.
Extensions to the underlying vCard specification must not lead to
requiring an update to jCard.
2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
The underlying format used for jCard is JSON. Consequently, the
terms "object" and "array" as well as the four primitive types
(strings, numbers, booleans, and null) are to be interpreted as
described in Section 1 of [RFC4627].
Some examples in this document contain "partial" JSON documents used
for illustrative purposes. In these examples, three periods "..."
are used to indicate a portion of the document that has been removed
for compactness.
3. Converting from vCard to jCard
This section describes how vCard objects are converted to jCard using
a simple mapping between the vCard data model and JSON elements.
In [RFC6350], vCard objects are comprised of a set of "properties",
"parameters", and "values". The top level of a vCard object contains
"properties". A "property" has a "value" and a set of zero or more
"parameters". Each of these entities has a representation in jCard,
defined in the following sections. The representation of a vCard
object in JSON will be named "jCard object" throughout this document.
3.1. Pre-processing
vCard uses a line-folding mechanism to limit lines of data to a
maximum line length (typically 75 octets) to ensure maximum
likelihood of preserving data integrity as it is transported via
various means (e.g., email) -- see Section 3.2 of [RFC6350].
vCard data uses an "escape" character sequence for text values and
property parameter values. See Section 3.4 of [RFC6350] as well as
[RFC6868].
When converting from vCard to jCard, first vCard lines MUST be
unfolded. Afterwards, any vCard escaping MUST be unescaped.
Finally, JSON escaping (e.g., for control characters) MUST be
applied.
The reverse order applies when converting from jCard to vCard.
First, JSON escaping MUST be unescaped. Afterwards, vCard escaping
MUST be applied. Finally, long lines SHOULD be folded as described
in [RFC6350].
One key difference in the formatting of values used in vCard and
jCard is that in jCard the specification uses date/time values
aligned with the extended format of [ISO.8601.2004], which is more
commonly used in Internet applications that make use of the JSON
format. The sections of this document describing the various date
and time formats contain more information on the use of the complete
representation, reduced accuracy, or truncated representation.
3.2. jCard Object and Syntactic Entities (RFC 6350, Sections 6.1.1 and
6.1.2)
In Sections 6.1.1 and 6.1.2 of [RFC6350], the BEGIN and END
properties delimit a syntactic vCard entity. In jCard, each
syntactic entity is represented by an array with two elements and is
named "jCard object". The first element is the string "vcard", and
the second element is an array of jCard properties as described in
Section 3.3, belonging to the entity.
Although [RFC6350] defines BEGIN and END to be properties, they MUST
NOT appear as properties of the jCard. Instead, the jCard object is
sufficient to define a vCard entity. When converting from jCard to
vCard, the BEGIN and END properties MUST be added to enclose the
properties of the jCard object.
Example:
["vcard", [
/* Add properties in place of this comment */
]
]
Consumers of this format wishing to define content that can represent
multiple jCard objects within the same JSON document can use a simple
JSON array, each element being a single jCard object.
3.3. Properties (RFC 6350, Section 6)
Each individual vCard property is represented in jCard by an array
with three fixed elements, followed by one or more additional
elements, depending on if the property is a multi-valued property as
described in Section 3.3 of [RFC6350].
The array consists of the following fixed elements:
1. The name of the property, as a lowercase string. The vCard
format specifies that property names are case insensitive and
recommends that they be rendered in uppercase. In jCard, they
MUST be in lowercase.
2. An object containing the parameters as described in Section 3.4.
If the property has no parameters, an empty object is used to
represent that.
3. The type identifier string of the value, in lowercase. It is
important that parsers check this to determine the data type of
the value and that they do not rely on assumptions. For example,
for structured values, the data type will be "array".
The remaining elements of the array are used for one or more values
of the property. For single-value properties, the array has exactly
four elements; for multi-valued properties, each value is another
element, and there can be any number of additional elements.
In the following example, the "categories" property is multi-valued
and has two values, while all other properties are single-valued:
["vcard",
[
["version", {}, "text", "4.0"],
["fn", {}, "text", "John Doe"],
["gender", {}, "text", "M"],
["categories", {}, "text", "computers", "cameras"],
...
]
]
As described in Section 3.3.1.3, a property value may be a structured
property value, in which case it is represented as an array
encapsulated in the array that represents the overall property.
Strictly speaking, this means that the property value is not
represented in the format indicated by the type identifier but by an
array instead. However, the values inside the encapsulated array are
of the format identified by the type identifier.
The above also holds for multi-valued properties, where some of the
values may be structured property values and therefore are
represented as an encapsulated array.
A special case is where a value in an encapsulated array consists of
multiple components itself, in which case it is represented as yet
another nested array, with elements matching the value type.
Section 3.3.1.3 describes this in more detail.
The above illustrates that it's important for the parser to check the
format of each property value, as it might either directly match the
value type, or it might be a structured value where nested
subelements match the value type.
3.3.1. Special Cases for Properties
This section describes some properties that have special handling
when converting to jCard.
3.3.1.1. The VERSION Property
The vCard format specification [RFC6350] defines the "VERSION"
property to be mandatory. The jCard "version" property MUST be
represented in the corresponding jCard component, with the same value
as in the vCard. vCards that conform to RFC 6350 will contain the
value "4.0".
Also in accordance to [RFC6350], the "version" property MUST be the
first element of the array containing the properties of a jCard.
3.3.1.2. Grouping of Properties
In vCard [RFC6350], related properties can be grouped together using
a grouping construct. The grouping is accomplished by adding a
prefix (which consists of the group name followed by a dot) to the
property name.
In jCard, the same grouping is achieved through a "group" parameter
that holds the group name. In jCard, a property name therefore MUST
NOT be prefixed by a group name.
The "GROUP" parameter MUST NOT be used in vCard; as per [RFC6350], it
is merely registered to reserve the parameter, avoiding collisions.
Formal registration of the "GROUP" parameter is described in
Section 7.1.
3.3.1.2.1. Group Conversion Rules
In jCard, the parameter's value is a single opaque string.
Conversion rules are as follows:
o From vCard to jCard, the group construct (see [RFC6350],
Section 3.3) is removed. In its place, the "group" parameter is
used. Its value is a string corresponding to the group name,
which is case insensitive both in vCard and jCard. The name's
case SHOULD be converted into lowercase.
o When converting from jCard to vCard, the value of the "group"
parameter followed by a dot is prefixed to the property name, and
the "group" parameter is discarded. The "GROUP" parameter MUST
NOT appear in the resulting vCard. Following the recommendations
in [RFC6350], the name's case SHOULD be converted into uppercase.
Example:
CONTACT.FN:Mr. John Q. Public\, Esq.
is equivalent to:
[ "fn", { "group": "CONTACT" }, "text", "Mr. John Q. Public, Esq." ]
3.3.1.3. Structured Property Values
The vCard specification defines properties with structured values,
for example, "GENDER" or "ADR". In vCard, a structured text value
consists of one or multiple text components, delimited by the
SEMICOLON character. Its equivalent in jCard is a structured
property value, which is an array containing one element for each
text component, with empty/missing text components represented by
zero-length strings.
vCard Example:
ADR:;;123 Main Street;Any Town;CA;91921-1234;U.S.A.
jCard Example:
["adr", {}, "text",
[
"", "", "123 Main Street",
"Any Town", "CA", "91921-1234", "U.S.A."
]
]
Some vCard properties, for example, ADR, also allow a structured
value element that itself has multiple values. In this case, the
element of the array describing the structured value is itself an
array with one element for each of the component's multiple values.
vCard Example:
ADR:;;My Street,Left Side,Second Shack;Hometown;PA;18252;U.S.A.
jCard Example:
["adr", {}, "text",
[
"", "",
["My Street", "Left Side", "Second Shack"],
"Hometown", "PA", "18252", "U.S.A."
]
]
In both cases, the array element values MUST have the primitive type
that matches the jCard type identifier. In [RFC6350], there are only
structured text values and thus only JSON strings are used. For
example, extensions may define structured number or boolean values,
where JSON number or boolean types MUST be used.
Although it is allowed for a structured property value to hold just
one component, it is RECOMMENDED to represent it as a single text
value instead, omitting the array completely. Nevertheless, a simple
implementation MAY choose to retain the array, with a single text
value as its element.
Similarly, structured values that consist of two text components with
one being optional (for example, "GENDER") can be represented as a
single text value. Therefore, parsers of jCard data SHOULD check
even known property values for structured information by considering
the JSON data type of the value, which can be an array or a primitive
value. This is especially important for languages where accessing
array members is done by the same construct as accessing characters
of a string.
Examples:
["gender", {}, "text", ["F", "grrrl"] ],
["gender", {}, "text", "M" ]
Per Section 6.3.1 of [RFC6350], the component separator MUST be
specified even if the component value is missing. Similarly, the
jCard array containing the structured data MUST contain all required
elements, even if they are empty.
vCard Example:
ADR;LABEL="123 Maple Ave\nSuite 901\nVancouver BC\nA1B 2C9\nCan
ada":;;;;;;
jCard Example:
["adr",
{"label":"123 Maple Ave\nSuite 901\nVancouver BC\nA1B 2C9\nCanada"},
"text",
["", "", "", "", "", "", ""]
]
3.4. Parameters (RFC 6350, Section 5)
Property parameters are represented as a JSON object where each key-
value pair represents the vCard parameter name and its value. The
name of the parameter MUST be in lowercase; the original case of the
parameter value MUST be preserved. For example, the "LANGUAGE"
property parameter is represented in jCard by the "language" key.
Any new vCard parameters added in the future will be converted in the
same way.
Example:
["role", { "language": "tr" }, "text", "roca"],
3.4.1. VALUE Parameter
vCard defines a "VALUE" property parameter (Section 5.2 of
[RFC6350]). This property parameter MUST NOT be added to the
parameters object. Instead, the value type is signaled through the
type identifier in the third element of the array describing the
property. When converting a property from vCard to jCard, the value
type is determined as follows:
1. If the property has a "VALUE" parameter, that parameter's value
is used as the value type.
2. If the property has no "VALUE" parameter but has a default value
type, the default value type is used.
3. If the property has no "VALUE" parameter and has no default value
type, "unknown" is used.
Converting from jCard into vCard is done as follows:
1. If the property's value type is "unknown", no "VALUE" parameter
is included.
2. If the property's value type is the default type for that
property, no "VALUE" parameter is included.
3. Otherwise, a "VALUE" parameter is included, and the value type is
used as the parameter value.
See Section 5 for information on handling unknown value types.
3.4.2. Multi-Valued Parameters
In [RFC6350], some parameters allow using a comma-separated list of
values. To ease processing in jCard, the value for such parameters
MUST be represented in an array containing the separated values. The
array elements MUST be string values. Single-value parameters SHOULD
be represented using a single string value, although a more simple
implementation might prefer an array with one string element. An
example of such a parameter is the vCard "SORT-AS" parameter; more
such parameters may be added in extensions.
The vCard specification requires encapsulation between DQUOTE
characters if a parameter value contains a colon, a semicolon, or a
comma. These extra DQUOTE characters do not belong to the actual
parameter value and hence are not included when the parameter is
converted to jCard.
Example:
["vcard",
[
["version", {}, "text", "4.0"],
["n",
{ "sort-as": ["Harten", "Rene"] },
"text",
["van der Harten", "Rene", "J.", "Sir", "R.D.O.N."]
],
["fn", {}, "text", "Rene van der Harten"]
...
]
]
3.5. Values (RFC 6350, Section 4)
The following subsections specify how vCard property value data types
(which are defined in Section 4 of [RFC6350]) are represented in
jCard.
3.5.1. Text (RFC 6350, Section 4.1)
Description: vCard "TEXT" property values are represented by a
property with the type identifier "text". The value elements are
JSON strings. For details on structured text values, see
Section 3.3.1.3.
Example:
["kind", {}, "text", "group"]
3.5.2. URI (RFC 6350, Section 4.2)
Description: vCard "URI" property values are represented by a
property with the type identifier "uri". The value elements are
JSON strings.
Example:
["source", {}, "uri", "ldap://ldap.example.com/cn=babs%20jensen"]
3.5.3. Date (RFC 6350, Section 4.3.1)
Description: vCard "DATE" property values are represented by a
property with the type identifier "date". The value elements are
JSON strings with the same date value specified by [RFC6350], but
represented using the extended format specified in
[ISO.8601.2004], Section 4.1.2. If the complete representation is
not used, the same date format restrictions regarding reduced
accuracy, truncated representation, and expanded representation
noted in [RFC6350], Section 4.3.1 apply. Whenever the extended
format is not applicable, the basic format MUST be used.
ABNF syntax:
date-complete = year "-" month "-" day ;YYYY-MM-DD
date-noreduc = date-complete
/ "--" month "-" day ; --MM-DD
/ "---" day ; ---DDD
date = date-noreduc
/ year; YYYY
/ year "-" month ; YYYY-MM
/ "--" month ; --MM
Examples:
["bday", {}, "date", "1985-04-12"],
["bday", {}, "date", "1985-04"],
["bday", {}, "date", "1985"],
["bday", {}, "date", "--04-12"],
["bday", {}, "date", "---12"]
This table contains possible conversions between the vCard DATE
format and jCard date. This information is just an example and not a
formal specification of the syntax. The specification can be found
in [ISO.8601.2000] and [ISO.8601.2004].
+-----------+----------+------------+
| | vCard | jCard |
+-----------+----------+------------+
| Complete | 19850412 | 1985-04-12 |
| | | |
| Reduced | 1985-04 | 1985-04 |
| | | |
| Reduced | 1985 | 1985 |
| | | |
| Truncated | --0412 | --04-12 |
| | | |
| Truncated | --04 | --04 |
| | | |
| Truncated | ---12 | ---12 |
+-----------+----------+------------+
3.5.4. Time (RFC 6350, Section 4.3.2)
Description: vCard "TIME" property values are represented by a
property with the type identifier "time". The value elements are
JSON strings with the same time value specified by [RFC6350], but
represented using the extended format specified in
[ISO.8601.2004], Section 4.2. If the complete representation is
not used, the same time format restrictions regarding reduced
accuracy, decimal fraction, and truncated representation noted in
[RFC6350], Section 4.3.2 apply. Whenever the extended format is
not applicable, the basic format MUST be used. The seconds value
of 60 MUST only be used to account for positive "leap" seconds,
and the midnight hour is always represented by 00, never 24.
Fractions of a second are not supported by this format. In jCard,
UTC offsets are permitted within a time value; note that this
differs from jCal [JCAL], where they are not permitted.
ABNF syntax:
time-notrunc = hour [":" minute [":" second]] [zone]
time = time-notrunc
/ "-" minute ":" second [zone]; -mm:ss
/ "-" minute [zone]; -mm
/ "--" second [zone]; --ss
Examples:
["x-time-local", {}, "time", "12:30:00"],
["x-time-utc", {}, "time", "12:30:00Z"],
["x-time-offset", {}, "time", "12:30:00-08:00"],
["x-time-reduced", {}, "time", "23"],
["x-time-truncated", {}, "time", "-30"]
This table contains possible conversions between the vCard TIME
format and jCard time. This information is just an example and not a
formal specification of the syntax. The specification can be found
in [ISO.8601.2000] and [ISO.8601.2004].
+-----------+--------+----------+
| | vCard | jCard |
+-----------+--------+----------+
| Complete | 232050 | 23:20:50 |
| | | |
| Reduced | 2320 | 23:20 |
| | | |
| Reduced | 23 | 23 |
| | | |
| Truncated | -2050 | -20:50 |
| | | |
| Truncated | -20 | -20 |
| | | |
| Truncated | --50 | --50 |
+-----------+--------+----------+
Also, all combinations may have any zone designator appended, as in
the complete representation.
3.5.5. Date-Time (RFC 6350, Section 4.3.3)
Description: vCard "DATE-TIME" property values are represented by a
property with the type identifier "date-time". The value elements
are JSON strings with the same date value specified by [RFC6350],
but represented using the extended format specified in
[ISO.8601.2004], Section 4.3. If the complete representation is
not used, the same date and time format restrictions noted in
Sections 3.5.3 and 3.5.4 apply. Just as described in [RFC6350],
truncation of the date part is permitted.
Example:
["anniversary", {}, "date-time", "2013-02-14T12:30:00"],
["anniversary", {}, "date-time", "2013-01-10T19:00:00Z"],
["anniversary", {}, "date-time", "2013-08-15T09:45:00+01:00"],
["anniversary", {}, "date-time", "---15T09:45:00+01:00"]
This table contains possible conversions between the vCard DATE-TIME
format and jCard date-time. This information is just an example and
not a formal specification of the syntax. The specification can be
found in [ISO.8601.2000] and [ISO.8601.2004].
+----------------+----------------------+---------------------------+
| Representation | vCard | jCard |
+----------------+----------------------+---------------------------+
| Complete | 19850412T232050 | 1985-04-12T23:20:50 |
| | | |
| Complete | 19850412T232050Z | 1985-04-12T23:20:50Z |
| | | |
| Complete | 19850412T232050+0400 | 1985-04-12T23:20:50+04:00 |
| | | |
| Complete | 19850412T232050+04 | 1985-04-12T23:20:50+04 |
| | | |
| Reduced | 19850412T2320 | 1985-04-12T23:20 |
| | | |
| Reduced | 19850412T23 | 1985-04-12T23 |
| | | |
| Truncated and | --0412T2320 | --04-12T23:20 |
| Reduced | | |
| | | |
| Truncated and | --04T2320 | --04T23:20 |
| Reduced | | |
| | | |
| Truncated and | ---12T2320 | ---12T23:20 |
| Reduced | | |
| | | |
| Truncated and | --0412T2320 | --04-12T23:20 |
| Reduced | | |
| | | |
| Truncated and | --04T23 | --04T23 |
| Reduced | | |
+----------------+----------------------+---------------------------+
As specified in [ISO.8601.2000], the lower-order components may not
be omitted in the date part (reduced accuracy) and the higher-order
components may not be omitted in the time part (truncation). Also,
all combinations may have any zone designator appended, as in the
complete representation.
3.5.6. Date and/or Time (RFC 6350, Section 4.3.4)
Description: vCard "DATE-AND-OR-TIME" property values are
represented by a property with the type identifier "date-and-or-
time". The value elements are either a date-time (Section 3.5.5),
a date (Section 3.5.3), or a time (Section 3.5.4) value. Just as
described in Section 4.3.4 of [RFC6350], a stand-alone time value
MUST always be preceded by a "T".
Example:
["bday", {}, "date-and-or-time", "2013-02-14T12:30:00"],
["bday", {}, "date-and-or-time", "---22T14:00"]
["bday", {}, "date-and-or-time", "1985"],
["bday", {}, "date-and-or-time", "T12:30"]
3.5.7. Timestamp (RFC 6350, Section 4.3.5)
Description: vCard "TIMESTAMP" property values are represented by a
property with the type identifier "timestamp". The value elements
are JSON strings with the same timestamp value specified by
[RFC6350], but represented using the extended format and complete
representation specified in [ISO.8601.2004], Section 4.3.2.
Example:
["rev", {}, "timestamp", "2013-02-14T12:30:00"],
["rev", {}, "timestamp", "2013-02-14T12:30:00Z"],
["rev", {}, "timestamp", "2013-02-14T12:30:00-05"],
["rev", {}, "timestamp", "2013-02-14T12:30:00-05:00"]
This table contains possible conversions between the vCard TIMESTAMP
format and jCard timestamp. This information is just an example and
not a formal specification of the syntax. The specification can be
found in [ISO.8601.2000] and [ISO.8601.2004].
+----------------+----------------------+---------------------------+
| Representation | vCard | jCard |
+----------------+----------------------+---------------------------+
| Complete | 19850412T232050 | 1985-04-12T23:20:50 |
| | | |
| Complete | 19850412T232050Z | 1985-04-12T23:20:50Z |
| | | |
| Complete | 19850412T232050+0400 | 1985-04-12T23:20:50+04:00 |
| | | |
| Complete | 19850412T232050+04 | 1985-04-12T23:20:50+04 |
+----------------+----------------------+---------------------------+
3.5.8. Boolean (RFC 6350, Section 4.4)
Description: vCard "BOOLEAN" property values are represented by a
property with the type identifier "boolean". The value element is
a JSON boolean value.
Example:
["x-non-smoking", {}, "boolean", true]
3.5.9. Integer (RFC 6350, Section 4.5)
Description: vCard "INTEGER" property values are represented by a
property with the type identifier "integer". The value elements
are JSON primitive number values.
Examples:
["x-karma-points", {}, "integer", 42]
JSON allows decimals (e.g., 3.14) and exponents (e.g., 2e10) to be
used in numeric values. jCard does not prohibit this for "integer"
property values. However, since vCard does not support decimals or
exponents in integers, any decimals and exponents MUST be eliminated
when converting an "integer" value type property from jCard to vCard.
3.5.10. Float (RFC 6350, Section 4.6)
Description: vCard "FLOAT" property values are represented by a
property with the type identifier "float". The value elements are
JSON primitive number values.
Example:
["x-grade", {}, "float", 1.3]
JSON allows exponents (e.g., 2e10) to be used in numeric values.
jCard does not prohibit this for "float" property values. However,
since vCard does not support exponents in floats, any exponents MUST
be eliminated when converting a "float" value type property from
jCard to vCard.
3.5.11. UTC Offset (RFC 6350, Section 4.7)
Description: vCard "UTC-OFFSET" property values are represented by a
property with the type identifier "utc-offset". The value
elements are JSON strings with the same UTC offset value specified
by [RFC6350], with the exception that the hour and minute
components are separated by a ":" character, for consistency with
the [ISO.8601.2004] timezone offset, extended format.
Example:
// Note: [RFC6350] mentions use of utc-offset
// for the TZ property as NOT RECOMMENDED
["tz", {}, "utc-offset", "-05:00"]
3.5.12. Language Tag (RFC 6350, Section 4.8)
Description: vCard "LANGUAGE-TAG" property values are represented by
a property with the type identifier "language-tag". The value
elements are JSON strings containing a single language-tag, as
defined in [RFC5646].
Example:
["lang", {}, "language-tag", "de"]
3.6. Extensions (RFC 6350, Section 6.10)
vCard extension properties and property parameters (those with an
"X-" prefix in their name) are handled in the same way as other
properties and property parameters: the property is represented by an
array, the property parameter represented by an object. The property
or parameter name uses the same name as for the vCard extension, but
in lowercase. For example, the "X-FOO" property in vCard turns into
the "x-foo" jCard property. See Section 5 for how to deal with
default values for unrecognized extension properties or property
parameters.
4. Converting from jCard into vCard
When converting property and property parameter values, the names
SHOULD be converted to uppercase. Although vCard names are case
insensitive, common practice is to keep them all uppercase following
the actual definitions in [RFC6350].
Character escaping and line folding MUST be applied to the resulting
vCard data as required by [RFC6350] and [RFC6868].
When converting to vCard, the "VALUE" parameter MUST be added to
properties whose default value type is unknown but do not have a
jCard type identifier "unknown". The "VALUE" parameter MAY be
omitted for properties using the default value type. The "VALUE"
parameter MUST be omitted for properties that have the jCard type
identifier "unknown".
5. Handling Unrecognized Properties or Parameters
In vCard, properties can have one or more value types as specified by
their definition, with one of those values being defined as the
default. When a property uses its default value type, the "VALUE"
property parameter does not need to be specified on the property.
For example, "BDAY"'s default value type is "date-and-or-time", so
"VALUE=date-and-or-time" need not be set as a property parameter.
However, "BDAY" also allows a "text" value to be specified, and if
that is used, "VALUE=text" has to be set as a property parameter.
When new properties are defined or "X-" properties used, a vCard-to-
jCard converter might not recognize them, and not know what the
appropriate default value types are, yet it needs to be able to
preserve the values. A similar issue arises for unrecognized
property parameters.
In jCard, a new "unknown" property value type is introduced. Its
purpose is to allow preserving unknown property values when round-
tripping between jCard and vCard. To avoid collisions, this
specification reserves the "UNKNOWN" property value type in vCard.
It MUST NOT be used in any vCard as specified by [RFC6350], nor any
extensions to it. The type is hence registered to the "vCard Value
Data Types" registry; see Section 7.2.
5.1. Converting vCard into jCard
Any property that does not include a "VALUE" property parameter and
whose default value type is not known MUST be converted to a
primitive JSON string. The content of that string is the unprocessed
value text. Also, value type MUST be set to "unknown".
To correctly implement this format, it's critical to use the value
type "unknown" when the default value type is not known. If this
requirement is ignored and, for example, "text" is used, additional
escaping may occur that breaks round-tripping values.
Any unrecognized property parameter MUST be converted to a string
value, with its content set to the property parameter value text,
treated as if it were a "TEXT" value.
5.2. Converting jCard into vCard
In jCard, the value type is always explicitly specified. It is
converted to vCard using the vCard "VALUE" parameter, except in the
following two cases:
o If the value type specified in jCard matches the default value
type in vCard, the "VALUE" parameter MAY be omitted.
o If the value type specified in jCard is set to "unknown", the
"VALUE" parameter MUST NOT be specified. The value MUST be taken
over in vCard without processing.
5.3. Examples
The following is an example of an unrecognized vCard property (that
uses a "URI" value as its default), and the equivalent jCard
representation of that property.
vCard:
X-COMPLAINT-URI:mailto:abuse@example.org
jCard:
["x-complaint-uri", {}, "unknown", "mailto:abuse@example.org"]
The following is an example of how to cope with jCard data where the
parser was unable to identify the value type. Note how the "unknown"
value type is not added to the vCard data, and escaping, aside from
standard JSON string escaping, is not processed.
jCard:
["x-coffee-data", {}, "unknown", "Stenophylla;Guinea\\,Africa"]
vCard:
X-COFFEE-DATA:Stenophylla;Guinea\,Africa
There are no standard properties in [RFC6350] that have a default
type of integer. Consequently, this example uses the following
extended property that we treat as having a default type (namely,
integer) known to the parser in order to illustrate how a property
with a known default type would be transformed.
jCard:
["x-karma-points", {}, "integer", 95]
vCard:
X-KARMA-POINTS:95
The following is an example of an unrecognized vCard property
parameter (that uses a "FLOAT" value as its default) specified on a
recognized vCard property, and the equivalent jCard representation of
that property and property parameter.
vCard:
GENDER;X-PROBABILITY=0.8:M
jCard:
["gender", { "x-probability": "0.8" }, "text", "M"]
6. Security Considerations
This specification defines how vCard data can be "translated" between
two different data formats -- the original text format and JSON --
with a one-to-one mapping to ensure all the semantic data in one
format (properties, parameters, and values) are preserved in the
other. It does not change the semantic meaning of the underlying
data itself, or impose or remove any security considerations that
apply to the underlying data.
The use of JSON as a format does have its own inherent security risks
as discussed in Section 7 of [RFC4627]. Even though JSON is
considered a safe subset of JavaScript, it should be kept in mind
that a flaw in the parser for JSON data could still impose a threat
that doesn't arise with conventional vCard data.
With this in mind when using jCard, the parser for JSON data should
be aware of the security implications. For example, the use of
JavaScript's eval() function is only allowed using the regular
expression in Section 6 of [RFC4627]. A native parser with full
awareness of the JSON format should be preferred.
In addition, it is expected that this new format will result in vCard
data being more widely disseminated (e.g., with use in web
applications rather than just dedicated "contact managers").
In all cases, application developers have to conform to the semantics
of the vCard data as defined by [RFC6350] and associated extensions,
and all of the security considerations described in Section 9 of
[RFC6350], or any associated extensions, are applicable.
7. IANA Considerations
This document defines a MIME media type for use with vCard in JSON
data. This media type SHOULD be used for the transfer of calendaring
data in JSON.
Type name: application
Subtype name: vcard+json
Required parameters: none
Optional parameters: "version", as defined for the text/vcard media
type in [RFC6350], Section 10.1.
Encoding considerations: Same as encoding considerations of
application/json as specified in [RFC4627], Section 6.
Security considerations: See Section 6.
Interoperability considerations: This media type provides an
alternative format for vCard data based on JSON.
Published specification: This specification.
Applications which use this media type: Applications that currently
make use of the text/vcard media type can use this as an
alternative. Similarly, applications that use the application/
json media type to transfer directory data can use this to further
specify the content.
Fragment identifier considerations: N/A
Additional information:
Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): N/A
Macintosh file type code(s): N/A
Person & email address to contact for further information:
vcarddav@ietf.org
Intended usage: COMMON
Restrictions on usage: There are no restrictions on where this media
type can be used.
Author: See the "Author's Address" section of this document.
Change controller: IETF
7.1. GROUP vCard Parameter
IANA has added the "GROUP" parameter to the "vCard Parameters"
registry, initialized in Section 10.3.2 of [RFC6350]. Usage of the
"GROUP" parameter is further described in Section 3.3.1.2 of this
document.
Namespace: <empty>
Parameter name: GROUP
Purpose: To simplify the jCard format.
Description: The "GROUP" parameter is reserved for the exclusive use
of the jCard format described in this document. It MUST NOT be
used in plain vCard [RFC6350], nor in xCard [RFC6351].
Format definition: When converting from jCard to vCard, the value of
the "GROUP" parameter is used as part of the property name.
Therefore, the value is restricted to characters allowed in
property names, namely ALPHA, DIGIT, and "-" characters. When
used, the "GROUP" parameter MUST NOT be empty.
Example: As this registration serves as a reservation of the "GROUP"
parameter so that it is not used in vCard, there is no applicable
vCard example. Examples of its usage in jCard can be found in
this document.
7.2. UNKNOWN vCard Value Data Type
IANA has added the "UNKNOWN" value data type to the "vCard Value Data
Types" registry, initialized in Section 10.3.3 of [RFC6350]. Usage
of the "UNKNOWN" type is further described in Section 5 of this
document.
Value name: UNKNOWN
Purpose: To allow preserving property values whose default value
type is not known during round-tripping between jCard and vCard.
Format definition: (Not applicable)
Description: The "UNKNOWN" value data type is reserved for the
exclusive use of the jCard format. It MUST NOT be used in plain
vCard [RFC6350].
Example: As this registration serves as a reservation of the
"UNKNOWN" type so that it is not used in vCard, there is no
applicable vCard example. Examples of its usage in jCard can be
found in this document.
8. Acknowledgments
The author would like to thank the following for their valuable
contributions: Cyrus Daboo, Mike Douglass, William Gill, Erwin Rehme,
Dave Thewlis, Simon Perreault, Michael Angstadt, Peter Saint-Andre,
Bert Greevenbosch, and Javier Godoy. This specification originated
from the work of the XML-JSON technical committee of the Calendaring
and Scheduling Consortium.
9. References
9.1. Normative References
[ISO.8601.2000]
International Organization for Standardization, "Data
elements and interchange formats -- Information
interchange -- Representation of dates and times", ISO
8601, December 2000.
[ISO.8601.2004]
International Organization for Standardization, "Data
elements and interchange formats -- Information
interchange -- Representation of dates and times", ISO
8601, December 2004.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4627] Crockford, D., "The application/json Media Type for
JavaScript Object Notation (JSON)", RFC 4627, July 2006.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5646] Phillips, A. and M. Davis, "Tags for Identifying
Languages", BCP 47, RFC 5646, September 2009.
[RFC6350] Perreault, S., "vCard Format Specification", RFC 6350,
August 2011.
[RFC6868] Daboo, C., "Parameter Value Encoding in iCalendar and
vCard", RFC 6868, February 2013.
9.2. Informative References
[JCAL] Kewisch, P., Daboo, C., and M. Douglass, "jCal: The JSON
format for iCalendar", Work in Progress, December 2013.
[RFC5545] Desruisseaux, B., "Internet Calendaring and Scheduling
Core Object Specification (iCalendar)", RFC 5545,
September 2009.
[RFC6321] Daboo, C., Douglass, M., and S. Lees, "xCal: The XML
Format for iCalendar", RFC 6321, August 2011.
[RFC6351] Perreault, S., "xCard: vCard XML Representation", RFC
6351, August 2011.
[calconnect-artifacts]
The Calendaring and Scheduling Consortium, "Code Artifacts
and Schemas", <http://www.calconnect.org/artifacts.shtml>.
Appendix A. ABNF Syntax
Below is the ABNF syntax as per [RFC5234] for vCard in JSON. ABNF
symbols not described here are taken from [RFC4627]. The syntax is
non-normative and given for reference only.
The numeric section numbers given in the comments refer to sections
in [RFC6350]. Additional semantic restrictions apply, especially
regarding the allowed properties and subcomponents per component.
Details on these restrictions can be found in this document and
[RFC6350].
Additional ABNF syntax may be available on the Internet at
[calconnect-artifacts].
; A jCard object uses the name "vcard" and a properties array.
; Restrictions to which properties may be specified are to
; be taken from RFC 6350.
jcardobject = begin-array
DQUOTE component-name DQUOTE value-separator
properties-array
end-array
; A jCard property consists of the name string, parameters object,
; type string, and one or more values as specified in this document.
property = begin-array
DQUOTE property-name DQUOTE value-separator
params-object value-separator
DQUOTE type-name DQUOTE
property-value *(value-separator property-value)
end-array
properties-array = begin-array
[ property *(value-separator property) ]
end-array
; Property values depend on the type-name. Aside from the value types
; mentioned here, extensions may make use of other JSON value types.
property-value = simple-prop-value / structured-prop-value
simple-prop-value = string / number / true / false
structured-prop-value =
begin-array
[ structured-element *(value-separator structured-element) ]
end-array
; Each structured element may have multiple values if
; semantically allowed.
structured-element = simple-prop-value / structured-multi-prop
structured-multi-prop =
begin-array
[ simple-prop-value *(value-separator simple-prop-value) ]
end-array
; The jCard params-object is a JSON object that follows the semantic
; guidelines described in this document.
params-object = begin-object
[ params-member *(value-separator params-member) ]
end-object
params-member = DQUOTE param-name DQUOTE name-separator param-value
param-value = string / param-multi
param-multi = begin-array
[ string *(value-separator string) ]
end-array
; The type MUST be a valid type as described by this document. New
; value types can be added by extensions.
type-name = "text" / "uri" / "date" / "time" / "date-time" /
"boolean" / "integer" / "float" / "utc-offset" /
"language-tag" / x-type
; Property, parameter, and type names MUST be lowercase. Additional
; semantic restrictions apply as described by this document and
; RFC 6350.
component-name = lowercase-name
property-name = lowercase-name
param-name = lowercase-name
x-type = lowercase-name
lowercase-name = 1*(%x61-7A / DIGIT / "-")
Appendix B. Examples
This section contains an example of a vCard object with its jCard
representation.
B.1. Example: vCard of the Author of RFC 6350
B.1.1. vCard Data
BEGIN:VCARD
VERSION:4.0
FN:Simon Perreault
N:Perreault;Simon;;;ing. jr,M.Sc.
BDAY:--0203
ANNIVERSARY:20090808T1430-0500
GENDER:M
LANG;PREF=1:fr
LANG;PREF=2:en
ORG;TYPE=work:Viagenie
ADR;TYPE=work:;Suite D2-630;2875 Laurier;
Quebec;QC;G1V 2M2;Canada
TEL;VALUE=uri;TYPE="work,voice";PREF=1:tel:+1-418-656-9254;ext=102
TEL;VALUE=uri;TYPE="work,cell,voice,video,text":tel:+1-418-262-6501
EMAIL;TYPE=work:simon.perreault@viagenie.ca
GEO;TYPE=work:geo:46.772673,-71.282945
KEY;TYPE=work;VALUE=uri:
http://www.viagenie.ca/simon.perreault/simon.asc
TZ:-0500
URL;TYPE=home:http://nomis80.org
END:VCARD
B.1.2. jCard Data
["vcard",
[
["version", {}, "text", "4.0"],
["fn", {}, "text", "Simon Perreault"],
["n",
{},
"text",
["Perreault", "Simon", "", "", ["ing. jr", "M.Sc."]]
],
["bday", {}, "date-and-or-time", "--02-03"],
["anniversary",
{},
"date-and-or-time",
"2009-08-08T14:30:00-05:00"
],
["gender", {}, "text", "M"],
["lang", { "pref": "1" }, "language-tag", "fr"],
["lang", { "pref": "2" }, "language-tag", "en"],
["org", { "type": "work" }, "text", "Viagenie"],
["adr",
{ "type": "work" },
"text",
[
"",
"Suite D2-630",
"2875 Laurier",
"Quebec",
"QC",
"G1V 2M2",
"Canada"
]
],
["tel",
{ "type": ["work", "voice"], "pref": "1" },
"uri",
"tel:+1-418-656-9254;ext=102"
],
["tel",
{ "type": ["work", "cell", "voice", "video", "text"] },
"uri",
"tel:+1-418-262-6501"
],
["email",
{ "type": "work" },
"text",
"simon.perreault@viagenie.ca"
],
["geo", { "type": "work" }, "uri", "geo:46.772673,-71.282945"],
["key",
{ "type": "work" },
"uri",
"http://www.viagenie.ca/simon.perreault/simon.asc"
],
["tz", {}, "utc-offset", "-05:00"],
["url", { "type": "home" }, "uri", "http://nomis80.org"]
]
]
Author's Address
Philipp Kewisch
Mozilla Corporation
650 Castro Street, Suite 300
Mountain View, CA 94041
USA
EMail: mozilla@kewis.ch
URI: http://www.mozilla.org/