Calendaring Extensions to WebDAV (CalDAV)cyrus@daboo.nameOracle Corporation600 Blvd. de Maisonneuve WestSuite 1900MontrealQCH3A 3J2CAbernard.desruisseaux@oracle.comhttp://www.oracle.com/
Open Source Application Foundation
2064 Edgewood Dr.Palo AltoCA94303USlisa@osafoundation.orghttp://www.osafoundation.org/
Applications
calschedcalschcaldavcalendarcalendaringschedulingwebdaviCaliCalendartext/calendarHTTP
This document specifies a set of methods, headers, message bodies,
properties, and reports that define calendar access extensions to
the WebDAV protocol. The new protocol elements are intended to make
WebDAV-based calendaring and scheduling an interoperable standard
that supports calendar access, calendar management, calendar sharing,
and calendar publishing.
The concept of using HTTP and
WebDAV as a basis for a calendar
access protocol is by no means a new concept: it was discussed in
the IETF CALSCH working group as early as 1997 or 1998. Several
companies have implemented calendar access protocols using HTTP
to upload and download iCalendar
objects, and using WebDAV to get listings of resources.
However, those implementations do not interoperate because there
are many small and big decisions to be made in how to model
calendaring data as WebDAV resources, as well as how to implement
required features that aren't already part of WebDAV.
This document proposes a way to model calendar data in WebDAV,
with additional features to make an interoperable calendar
access protocol.
Discussion of this Internet-Draft is taking place on the mailing list
<http://lists.osafoundation.org/mailman/listinfo/ietf-caldav>.
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 .
The term "protected" is used in the Conformance field
of property definitions as defined in Section 1.4.2 of
.
When XML element types in the namespaces "DAV:" and
"urn:ietf:params:xml:ns:caldav" are referenced in this
document outside of the context of an XML fragment,
the string "DAV:" and "CALDAV:" will be prefixed to
the element type names respectively.
Definitions of XML elements in this document use XML element
type declarations (as found in XML Document Type Declarations),
described in Section 3.2 of .
The namespace "urn:ietf:params:xml:ns:caldav" is reserved
for the XML elements defined in this specification, its
revisions, and related CalDAV specifications. XML elements
defined by individual implementations MUST NOT use the
"urn:ietf:params:xml:ns:caldav" namespace, and instead
should use a namespace that they control.
The XML declarations used in this document do not include
namespace information. Thus, implementers MUST NOT use these
declarations as the only way to create valid CalDAV properties or
to validate CalDAV XML element type. Some of the declarations
refer to XML elements defined by WebDAV which use the
"DAV:" namespace. Wherever such XML elements appear, they are
explicitly prefixed with "DAV:" to avoid confusion.
Also note that some CalDAV XML element names are identical to
WebDAV XML element names, though their namespace differs. Care
must be taken not to confuse the two sets of names.
Processing of XML by CalDAV clients and servers MUST follow the
rules described in , in particular Sections 8.2 and 17, and Appendix A of that specification.
This section lists what functionality is required of a CalDAV
server. To advertise support for CalDAV, a server:
MUST support iCalendar as a
media type for calendar object resource format;
MUST support WebDAV Class 1 and Class 3;
MUST support WebDAV ACL with
the additional privilege defined in
of this document;
MUST support transport over TLS
as defined in ;
MUST support ETags with additional
requirements specified in of
this document;
MUST support all calendaring REPORTs defined in
of this document; and
MUST advertise support on all calendar collections and
calendar object resources for the calendaring REPORTs
in the DAV:supported-report-set property as defined in
Versioning Extensions to WebDAV.
In addition, a server:
SHOULD support the MKCALENDAR method defined in
of this document.
One of the features which has made WebDAV a successful protocol
is its firm data model. This makes it a useful framework for
other applications such as calendaring. This specification
follows the same pattern by developing all features based
on a well-described data model.
As a brief overview, a CalDAV calendar is modeled as a WebDAV
collection with a defined structure; each calendar collection contains
a number of resources representing calendar objects as its direct
child resource. Each resource representing a calendar object (event
or to-do, or journal entry, or other calendar components) is called
a "calendar object resource". Each calendar object resource and each
calendar collection can be individually locked and have individual
WebDAV properties. Requirements derived from this model are provided
in and
.
A CalDAV server is a calendaring-aware engine combined with
a WebDAV repository. A WebDAV repository is a set of WebDAV
collections, containing other WebDAV resources, within a
unified URL namespace. For example, the repository
"http://www.example.com/webdav/" may contain WebDAV
collections and resources, all of which have URLs beginning
with "http://www.example.com/webdav/". Note that the root
URL "http://www.example.com/" may not itself be a WebDAV
repository (for example, if the WebDAV support is implemented
through a servlet or other Web server extension).
A WebDAV repository MAY include calendar data in some parts
of its URL namespace, and non-calendaring data in other parts.
A WebDAV repository can advertise itself as a CalDAV server
if it supports the functionality defined in this
specification at any point within the root of the
repository. That might mean that calendaring data is spread
throughout the repository and mixed with non-calendar data
in nearby collections (e.g., calendar data may be found in
/home/lisa/calendars/ as well as in /home/bernard/calendars/,
and non-calendar data in /home/lisa/contacts/). Or, it might
mean that calendar data can be found only in certain sections of
the repository (e.g., /calendar/). Calendaring
features are only required in the repository sections that
are or contain calendar object resources. So a repository
confining calendar data to the /calendar/ collection would
only need to support the CalDAV required features within
that collection.
The CalDAV server or repository is the canonical location
for calendar data and state information. Both CalDAV
servers and clients MUST ensure that the data is consistent
and compliant. Clients may submit requests to change data
or download data. Clients may store calendar objects
offline and attempt to synchronize at a later time.
However, clients MUST be prepared for calendar data on the
server to change between the time of last synchronization
and when attempting an update, as calendar collections may
be shared and accessible via multiple clients. Entity tags
and other features make this possible.
Recurrence is an important part of the data model because it
governs how many resources are expected to exist. This
specification models a recurring calendar component and its
recurrence exceptions as a single resource. In this model,
recurrence rules, recurrence dates, exception rules, and
exception dates are all part of the data in a single
calendar object resource. This model avoids problems of limiting
how many recurrence instances to store in the repository, how to
keep recurrence instances in sync with the recurring calendar
component,
and how to link recurrence exceptions with the recurring calendar
component. It also results in less data to synchronize between
client and server, and makes it easier to make changes to all
recurrence instances or to a recurrence rule. It makes it
easier to create a recurring calendar component, and easier
to delete all recurrence instances.
Clients are not forced to retrieve information about all recurrence
instances of a recurring component. The CALDAV:calendar-query and
CALDAV:calendar-multiget REPORTs defined in this document allow
clients to retrieve only recurrence instances that overlap a
given time range.
Calendar object resources contained in calendar collections MUST
NOT contain more than one type of calendar component (e.g.,
VEVENT, VTODO, VJOURNAL, VFREEBUSY, etc.) with the exception of
VTIMEZONE components which MUST be specified for each unique TZID
parameter value specified in the iCalendar object. For instance,
a calendar object resource can contain two VEVENT components and
one VTIMEZONE component, but it cannot contain one VEVENT
component and one VTODO component. Instead the VEVENT and VTODO
components would have to be stored in separate calendar object
resources in the same collection.
Calendar object resources contained in calendar collections MUST
NOT specify the iCalendar METHOD property.
The UID property value of the calendar components contained in a
calendar object resource MUST be unique in the scope of the
calendar collection in which they are stored.
Calendar components in a calendar collection that have
different UID property values MUST be stored in separate calendar
object resources.
Calendar components with the same UID property value, in a given
calendar collection, MUST be contained in the same calendar object
resource. This ensures that all components in a recurrence "set"
are contained in the same calendar object resource. It is possible
for a calendar object resource to just contain components that represent
"overridden" instances (ones which modify the behavior of a regular
instance, and thus include a RECURRENCE-ID property),
without also including the "master" recurring component (the one that
defines the recurrence "set" and does not contain any "RECURRENCE-ID"
property).
For example, given the following iCalendar object:
The VEVENT component with the UID value "1@example.com", would
be stored in its own calendar object resource. The two
VEVENT components with the UID value "2@example.com", which
represent a recurring event where one recurrence instance has
been overridden, would be stored in the same calendar object
resource.
A calendar collection contains calendar object resources that
represent calendar components within a calendar. A calendar
collection is manifested to clients as a WebDAV resource
collection identified by a URL. A calendar collection MUST
report the DAV:collection and CALDAV:calendar XML elements
in the value of the DAV:resourcetype property. The element
type declaration for CALDAV:calendar is:
]]>
A calendar collection can be created through provisioning (e.g.,
automatically created when a user's account is provisioned),
or it can be created with the MKCALENDAR method (see
). This method can be useful
for a user to create additional calendars (e.g., soccer
schedule) or for users to share a calendar (e.g., team
events or conference room). Note however that this document
doesn't define what extra calendar collections are for.
Users must rely on non-standard cues to find out what a
calendar collection is for, or use the
CALDAV:calendar-description property defined
in to provide such a
cue.
The following restrictions are applied to the resources within a calendar collection:
Calendar collections MUST only contain calendar object
resources and collections that are not calendar collections.
i.e., the only "top-level" non-collection resources allowed in
a calendar collection are calendar object resources. This
ensures that calendar clients do not have to deal with
non-calendar data in a calendar collection, though they do have
to distinguish between calendar object resources and
collections when using standard WebDAV techniques to examine
the contents of a collection.
Collections contained in calendar collections MUST NOT contain
calendar collections at any depth. i.e., "nesting" of calendar
collections within other calendar collections at any depth is
not allowed. This specification does not define how collections
contained in a calendar collection are used or how they relate to
any calendar object resources contained in the calendar
collection.
Multiple calendar collections MAY be children of the same
collection.
A server supporting the features described in this document MUST
include "calendar-access" as a field in the DAV response header
from an OPTIONS request on any resource that supports any
calendar properties, reports, method, or privilege. A value of
"calendar-access" in the DAV response header MUST indicate that
the server supports all MUST level requirements specified in this
document.
>> Request <<>> Response <<
In this example, the OPTIONS method returns the value
"calendar-access" in the DAV response header to
indicate that the collection "/home/bernard/calendars/"
supports the properties, reports, methods, or privileges
defined in this specification.
This section defines properties that MAY be defined
on calendar collections.
calendar-description
urn:ietf:params:xml:ns:caldav
Provides a human-readable description of the calendar
collection.
This property MAY be defined on any calendar collection. If
defined, it MAY be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ). An
xml:lang attribute indicating the human language of the
description SHOULD be set for this property by clients or
through server provisioning. Servers MUST return any
xml:lang attribute if set for the property.
If present, the property contains a description of the
calendar collection that is suitable for presentation to a
user. If not present, the client should assume no
description for the calendar collection.
PCDATA value: string
]]>Calendrier de Mathilde Desruisseaux
]]>
calendar-timezone
urn:ietf:params:xml:ns:caldav
Specifies a time zone on a calendar collection.
This property SHOULD be defined on all calendar
collections. If defined, it SHOULD NOT be returned by a
PROPFIND DAV:allprop request (as defined in Section 14.2 of
).
The CALDAV:calendar-timezone property is used to specify
the time zone the server should rely on to resolve "date"
values and "date with local time" values (i.e., floating
time) to "date with UTC time" values. The server will
require this information to determine if a calendar
component scheduled with "date" values or "date with local
time" values overlaps a CALDAV:time-range specified in a
CALDAV:calendar-query REPORT. The server will also require
this information to compute the proper FREEBUSY time period
as "date with UTC time" in the VFREEBUSY component returned
in a response to a CALDAV:free-busy-query REPORT request
that takes into account calendar components scheduled with
"date" values or "date with local time" values. In the
absence of this property the server MAY rely on the time
zone of their choice.
The iCalendar data embedded within the CALDAV:calendar-timezone XML
element MUST follow the standard XML character data encoding rules,
including use of <, >, & etc entity encoding
or the use of a <[!CDATA[ ... ]]> construct. In the later case
the iCalendar data cannot contain the character sequence "]]>"
which is the end delimiter for the CDATA section.
PCDATA value: an iCalendar object with exactly one VTIMEZONE
component.
]]>BEGIN:VCALENDAR
PRODID:-//Example Corp.//CalDAV Client//EN
VERSION:2.0
BEGIN:VTIMEZONE
TZID:US-Eastern
LAST-MODIFIED:19870101T000000Z
BEGIN:STANDARD
DTSTART:19671029T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:Eastern Standard Time (US & Canada)
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:19870405T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:Eastern Daylight Time (US & Canada)
END:DAYLIGHT
END:VTIMEZONE
END:VCALENDAR
]]>
supported-calendar-component-set
urn:ietf:params:xml:ns:caldav
Specifies the calendar component types
(e.g., VEVENT, VTODO, etc.) that calendar object
resources can contain in the calendar collection.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ).
The CALDAV:supported-calendar-component-set property is
used to specify restrictions on the calendar component
types that calendar object resources may contain in a
calendar collection. Any attempt by the client to store
calendar object resources with component types not listed
in this property, if it exists, MUST result in an error,
with the CALDAV:supported-calendar-component precondition
() being violated. Since
this property is protected it cannot be changed by clients
using a PROPPATCH request. However, clients can initialize
the value of this property when creating a new calendar
collection with MKCALENDAR. The empty-element tag
<C:comp name="VTIMEZONE"/> MUST only be specified if
support for calendar object resources that only contain
VTIMEZONE components is provided or desired. Support for
VTIMEZONE components in calendar object resources that
contain VEVENT or VTODO components is always assumed. In
the absence of this property the server MUST accept all
component types, and the client can assume that.
]]>
]]>
supported-calendar-data
urn:ietf:params:xml:ns:caldav
Specifies what media types are allowed for calendar object
resources in a calendar collection.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ).
The CALDAV:supported-calendar-data property is used to
specify the media type supported for the calendar object
resources contained in a given calendar collection (e.g.,
iCalendar version 2.0). Any attempt by the client to store
calendar object resources with a media type not listed in
this property MUST result in an error, with the
CALDAV:supported-calendar-data precondition () being violated. In the absence
of this property the server MUST accept data with the media
type "text/calendar" and iCalendar version 2.0, and clients
can assume that.
]]>
]]>
max-resource-size
urn:ietf:params:xml:ns:caldav
Provides a numeric value indicating the maximum size of
resource in octets that the server is willing to accept
when a calendar object resource is stored in a calendar
collection.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ).
The CALDAV:max-resource-size is used to specify a numeric
value that represents the maximum size in octets that the
server is willing to accept when a calendar object resource
is stored in a calendar collection. Any attempt to store a
calendar object resource exceeding this size MUST result in
an error, with the CALDAV:max-resource-size precondition
() being violated. In the
absence of this property the client can assume that the
server will allow storing a resource of any reasonable size.
PCDATA value: a numeric value (positive integer)
]]>102400
]]>
min-date-time
urn:ietf:params:xml:ns:caldav
Provides a date-time value indicating the earliest date and
time (in UTC) that the server is willing to accept for any
date or time value in a calendar object resource stored in
a calendar collection.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by a
PROPFIND DAV:allprop request (as defined in Section 14.2 of
).
The CALDAV:min-date-time is used to specify an iCalendar
DATE-TIME value in UTC that indicates the earliest
inclusive date that the server is willing to accept for any
explicit date or time value in a calendar object resource
stored in a calendar collection. Any attempt to store a
calendar object resource using a date or time value earlier
than this value MUST result in an error, with the
CALDAV:min-date-time precondition () being violated. Note that
servers MUST accept recurring components that specify
instances beyond this limit, provided none of those
instances have been overridden. In that case the server
MAY simply ignore those instances outside of the
acceptable range when processing reports on the calendar
object resource. In the absence of this property the client
can assume any valid iCalendar date may be used at least up
to the CALDAV:max-date-time value if that is defined.
PCDATA value: an iCalendar format DATE-TIME value in UTC
]]>19000101T000000Z
]]>
max-date-time
urn:ietf:params:xml:ns:caldav
Provides a date-time value indicating the latest date and
time (in UTC) that the server is willing to accept for any
date or time value in a calendar object resource stored in
a calendar collection.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ).
The CALDAV:max-date-time is used to specify an iCalendar
DATE-TIME value in UTC that indicates the inclusive latest
date that the server is willing to accept for any date or
time value in a calendar object resource stored in a
calendar collection. Any attempt to store a calendar object
resource using a date or time value later than this value
MUST result in an error, with the CALDAV:max-date-time
precondition () being
violated. Note that servers MUST accept recurring
components that specify instances beyond this limit,
provided none of those instances have been overridden. In
that case the server MAY simply ignore those instances
outside of the acceptable range when processing reports on
the calendar object resource. In the absence of this
property the client can assume any valid iCalendar date may
be used at least down to the CALDAV:min-date-time value if
that is defined.
PCDATA value: an iCalendar format DATE-TIME value in UTC
]]>20491231T235959Z
]]>
max-instances
urn:ietf:params:xml:ns:caldav
Provides a numeric value indicating the maximum number of
recurrence instances that a calendar object resource stored
in a calendar collection can generate.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ).
The CALDAV:max-instances is used to specify a numeric
value that indicates the maximum number of recurrence
instances that a calendar object resource stored in a
calendar collection can generate. Any attempt to store a
calendar object resource with a recurrence pattern that
generates more instances than this value MUST result in an
error, with the CALDAV:max-instances precondition () being violated. In the absence
of this property the client can assume that the server has
no limits on the number of recurrence instances it can
handle or expand.
PCDATA value: a numeric value (integer greater than zero)
]]>100
]]>
max-attendees-per-instance
urn:ietf:params:xml:ns:caldav
Provides a numeric value indicating the maximum number of
ATTENDEE properties in any instance of a calendar object
resource stored in a calendar collection.
This property MAY be defined on any calendar collection. If
defined, it MUST be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ).
The CALDAV:max-attendees-per-instance is used to specify a
numeric value that indicates the maximum number of
iCalendar ATTENDEE properties on any one instance of a
calendar object resource stored in a calendar collection.
Any attempt to store a calendar object resource with more
ATTENDEE properties per instance than this value MUST
result in an error, with the
CALDAV:max-attendees-per-instance precondition () being violated. In the absence
of this property the client can assume that the server can
handle any number of ATTENDEE properties in a calendar
component.
PCDATA value: a numeric value (integer greater than zero)
]]>25
]]>
This specification requires an additional Precondition (see
Section 16 of for
the PROPPATCH method. The precondition is:
(CALDAV:valid-calendar-data): The time zone specified in
CALDAV:calendar-timezone property MUST be a valid
iCalendar object containing a single valid VTIMEZONE component.
The creation of calendar collections and calendar object resources may
be initiated by either a CalDAV client or by the CalDAV server. For
example, a server might come pre-configured with a user's calendar
collection, or the CalDAV client might request the server to create a
new calendar collection for a given user. Servers might populate
events as calendar objects inside a calendar collection, or clients
might request the server to create events. Either way, both client and
server MUST comply with the requirements in this document, and MUST
understand objects appearing in calendar collections or according to
the data model defined here.
An HTTP request using the MKCALENDAR method creates a new calendar
collection resource. A server MAY restrict calendar collection
creation to particular collections.
Support for MKCALENDAR on the server is only RECOMMENDED and not
REQUIRED because some calendar stores only support one calendar
per user (or principal) and those are typically pre-created for
each account. However, servers and clients are strongly encouraged
to support MKCALENDAR whenever possible to allow users to create
multiple calendar collections to better help organize their data.
Clients SHOULD use the DAV:displayname property for a
human-readable name of the calendar. Clients can either
specify the value of the DAV:displayname property in the
request body of the MKCALENDAR request, or alternatively
issue a PROPPATCH request to change the DAV:displayname property
to the appropriate value immediately after issuing the
MKCALENDAR request. Clients SHOULD NOT set the DAV:displayname
property to be the same as any other calendar collection at the same
URI "level". When displaying calendar collections to users,
clients SHOULD check the DAV:displayname property and use that
value as the name of the calendar. In the event that the
DAV:displayname property is empty, the client MAY use the last
part of the calendar collection URI as the name, however that
path segment may be "opaque" and not represent any meaningful
human-readable text.
If a MKCALENDAR request fails, the server state preceding the
request MUST be restored.
Marshalling:
If a request body is included, it MUST be a CALDAV:mkcalendar
XML element. Instruction processing MUST occur in the order
instructions are received (i.e., from top to bottom).
Instructions MUST either all be executed or none executed.
Thus if any error occurs during processing, all executed
instructions MUST be undone and a proper error result
returned. Instruction processing details can be found in
the definition of the DAV:set instruction in Section 14.26
of .
]]>
If a response body for a successful request is included, it MUST
be a CALDAV:mkcalendar-response XML element.
]]>
The response MUST include a Cache-Control:no-cache header.
Preconditions:
(DAV:resource-must-be-null): A resource MUST NOT exist
at the Request-URI;
(CALDAV:calendar-collection-location-ok): The
Request-URI MUST identify a location where a calendar
collection can be created;
(CALDAV:valid-calendar-data): The time zone specified in
the CALDAV:calendar-timezone property MUST be a valid
iCalendar object containing a single valid VTIMEZONE component;
(DAV:needs-privilege): The DAV:bind privilege MUST be
granted to the current user on the parent collection
of the Request-URI.
Postconditions:
(CALDAV:initialize-calendar-collection): A new
calendar collection exists at the Request-URI. The
DAV:resourcetype of the calendar collection MUST
contain both DAV:collection and CALDAV:calendar XML
elements.
The following are examples of response codes one would expect
to get in a response to a MKCALENDAR request. Note that this
list is by no means exhaustive.
201 (Created) - The calendar collection resource was created
in its entirety;
207 (Multi-Status) - The calendar collection resource was
not created since one or more DAV:set instructions specified
in the request body could not be processed successfully. The
following are examples of response codes one would expect
to be used in a 207 (Multi-Status) response in this situation:
403 (Forbidden) - The client, for reasons the server
chooses not to specify, cannot alter one of the properties;
409 (Conflict) - The client has provided a value whose
semantics are not appropriate for the property. This
includes trying to set read-only properties;
424 (Failed Dependency) - The DAV:set instruction on the
specified resource would have succeeded if it were not for
the failure of another DAV:set instruction specified in the
request body;
423 (Locked) - The specified resource is locked and the
client either is not a lock owner or the lock type
requires a lock token to be submitted and the client did
not submit it; and
507 (Insufficient Storage) - The server did not have
sufficient space to record the property;
403 (Forbidden) - This indicates at least one of two
conditions: 1) the server does not allow the creation of calendar
collections at the given location in its namespace, or 2) the
parent collection of the Request-URI exists but cannot accept
members;
409 (Conflict) - A collection cannot be made at the
Request-URI until one or more intermediate collections have been
created;
415 (Unsupported Media Type) - The server does not support
the request type of the body; and
507 (Insufficient Storage) - The resource does not have
sufficient space to record the state of the resource after the
execution of this method.
This example creates a calendar collection called
/home/lisa/calendars/events/ on the server
cal.example.com with specific values for the properties
DAV:displayname, CALDAV:calendar-description,
CALDAV:supported-calendar-component-set, and
CALDAV:calendar-timezone.
>> Request <<Lisa's EventsCalendar restricted to events.]]><![CDATA[]]>
]]>>> Response <<
Clients populate calendar collections with calendar object
resources. The URL for each calendar object resource is
entirely arbitrary, and does not need to bear a specific
relationship to the calendar object resource's iCalendar
properties or other metadata. New calendar object resources
MUST be created with a PUT request targeted at an unmapped URI. A PUT
request targeted at a mapped URI updates an existing calendar
object resource.
When servers create new resources, it's not hard for the server to
choose an unmapped URI. It's slightly tougher for clients, because a
client might not want to examine all resources in the collection,
and might not want to lock the entire collection to ensure that a new
resource isn't created with a name collision. However, there is an HTTP
feature to mitigate this. If the client intends to create a new
non-collection resource, such as a new VEVENT, the client SHOULD
use the HTTP request header "If-None-Match: *" on the PUT request.
The Request-URI on the PUT request MUST include the target
collection, where the resource is to be created, plus the name of
the resource in the last path segment. The "If-None-Match: *" request
header ensures that the client will not inadvertently overwrite an
existing resource, if the last path segment turned out to already be
used.
>> Request <<>> Response <<
The request to change an existing event is the same, but with a
specific ETag in the "If-Match" header, rather than the
"If-None-Match" header.
As indicated in Section 3.10 of
, the URL of calendar
object resources containing (an arbitrary set of) calendaring
and scheduling information may be suffixed by ".ics", and the URL
of calendar object resources containing free or busy time
information may be suffixed by ".ifb".
This specification creates additional Preconditions (see
Section 16 of for
PUT, COPY and MOVE methods. These preconditions apply:
When a PUT operation of a calendar object resource into
a calendar collection occurs.When a COPY or MOVE operation of a calendar object resource into
a calendar collection occurs.The new preconditions are:
(CALDAV:supported-calendar-data): The resource submitted in
the PUT request, or targeted by a COPY or MOVE request MUST
be a supported media type (i.e., iCalendar) for calendar object
resources;
(CALDAV:valid-calendar-data): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST be valid
data for the media type being specified (i.e., MUST contain valid
iCalendar data);
(CALDAV:valid-calendar-object-resource): The resource
submitted in the PUT request, or targeted by a COPY or MOVE request
MUST obey all restrictions specified in
(e.g., calendar object resources MUST NOT contain more
than one type of calendar component, calendar object
resources MUST NOT specify the iCalendar METHOD property,
etc.);
(CALDAV:supported-calendar-component): The resource
submitted in the PUT request, or targeted by a COPY or MOVE request
MUST contain a type of calendar component that is supported in the
targeted calendar collection;
(CALDAV:no-uid-conflict): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST NOT
specify an iCalendar UID property
value already in use in the targeted calendar collection
or overwrite an existing calendar object resource with
one that has a different UID
property value. Servers SHOULD report the URL of the
resource that is already making use of the same UID
property value in the DAV:href element;
]]>
(CALDAV:calendar-collection-location-ok): In a COPY or
MOVE request, when the Request-URI is a calendar collection,
the Destination-URI MUST identify a location where a calendar
collection can be created;
(CALDAV:max-resource-size): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST have an octet size less than or equal to the value of the CALDAV:max-resource-size property value () on the calendar collection where the resource will be stored;
(CALDAV:min-date-time): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST have all of its iCalendar date or time property values (for each recurring instance) greater than or equal to the value of the CALDAV:min-date-time property value () on the calendar collection where the resource will be stored;
(CALDAV:max-date-time): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST have all of its iCalendar date or time property values (for each recurring instance) less than the value of the CALDAV:max-date-time property value () on the calendar collection where the resource will be stored;
(CALDAV:max-instances): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST generate a number of recurring instances less than or equal to the value of the CALDAV:max-instances property value () on the calendar collection where the resource will be stored;
(CALDAV:max-attendees-per-instance): The resource submitted in the
PUT request, or targeted by a COPY or MOVE request MUST have a number of ATTENDEE properties on any one instance less than or equal to the value of the CALDAV:max-attendees-per-instance property value () on the calendar collection where the resource will be stored;
iCalendar provides a "standard mechanism for doing non-standard
things". This extension support allows implementers to make use of
non-standard components, properties and parameters whose names are
prefixed with the text "X-".
Servers MUST support the use of non-standard components,
properties and parameters in calendar object resources stored
via the PUT method.
Servers may need to enforce rules for their own "private"
components, properties or parameters, so servers MAY reject
any attempt by the client to change those or use values for
those outside of any restrictions the server may have. Servers
SHOULD ensure that any "private" components, properties or
parameters it uses follow the convention of including a vendor
id in the "X-" name as described in Section 4.2 of , e.g., "X-ABC-Private".
The DAV:getetag property MUST be defined and set to a strong
entity tag on all calendar object resources.
A response to a GET request targeted at a calendar object
resource MUST contain an ETag response header field
indicating the current value of the strong entity tag of
the calendar object resource.
Servers SHOULD return a strong entity tag (ETag header) in a PUT
response when the stored calendar object resource is equivalent
by octet equality to the calendar object resource submitted in
the body of the PUT request. This allows clients to reliably use
the returned strong entity tag for data synchronization
purposes. For instance, the client can do a PROPFIND request on
the stored calendar object resource and have the DAV:getetag
property returned, and compare that value with the strong entity
tag it received on the PUT response, and know that if they are
equal, then the calendar object resource on the server has not
been changed.
In the case where the data stored by a server as a result of a
PUT request is not equivalent by octet equality to the submitted
calendar object resource, the behavior of the ETag response
header is undefined, with the exception that a strong entity tag
MUST NOT be returned in the response. As a result, clients may
need to retrieve the modified calendar object resource (and
ETag) as a basis for further changes, rather than use the
calendar object resource it had sent with the PUT request.
CalDAV servers MUST support and adhere to the requirements of
WebDAV ACL. WebDAV ACL provides
a framework for an extensible set of privileges that can be
applied to WebDAV collections and ordinary resources.
CalDAV servers MUST also support the calendaring privilege
defined in this section.
Calendar users often wish to allow other users to see their
busy time information, without viewing the other details
of the calendar components (e.g., location, summary, attendees).
This allows a significant amount of privacy while still
allowing other users to schedule meetings at times when
the user is likely to be free.
The CALDAV:read-free-busy privilege controls which calendar
collections, regular collections and calendar object resources
are examined when a CALDAV:free-busy-query REPORT request is
processed (see ). This
privilege can be granted on calendar collections, regular
collections or calendar object resources. Servers MUST support
this privilege on all calendar collections, regular collections
and calendar object resources.
]]>
The CALDAV:read-free-busy privilege MUST be aggregated in the
DAV:read privilege. Servers MUST allow the CALDAV:read-free-busy
to be granted without the DAV:read privilege being granted.
Clients should note that when only the CALDAV:read-free-busy
privilege has been granted on a resource, this does not imply
access to GET, HEAD, OPTIONS and PROPFIND on the resource --
those operations are governed by the DAV:read privilege.
This section defines an additional property for WebDAV principal
resources as defined in .
calendar-home-set
urn:ietf:params:xml:ns:caldav
Identifies the URL of any WebDAV collections that contain
calendar collections owned by the associated principal
resource.
This property MAY be defined in a principal resource. If
defined, it MAY be protected and SHOULD NOT be returned by
a PROPFIND DAV:allprop request (as defined in Section 14.2
of ). Support
for this property is RECOMMENDED.
The CALDAV:calendar-home-set property is meant to allow
users to easily find the calendar collections owned by
the principal. Typically, users will group all the
calendar collections that they own under a common
collection. This property specifies the URL of
collections that either are calendar collections or
ordinary collections that have child or descendant
calendar collections owned by the principal.
]]>http://cal.example.com/home/bernard/calendars/
]]>
This section defines the REPORTs that CalDAV servers MUST
support on calendar collections and calendar object resources.
CalDAV servers MUST advertise support for these REPORTs
on all calendar collections and calendar object resources
with the DAV:supported-report-set property defined in
Section 3.1.5 of . CalDAV servers
MAY also advertise support for these REPORTs on ordinary
collections.
Some of these REPORTs allow calendar data (from possibly
multiple resources) to be returned.
The REPORT method (defined in Section 3.6 of
) provides an
extensible mechanism for obtaining information about one or
more resources. Unlike the PROPFIND method, which returns
the value of one or more named properties, the REPORT method
can involve more complex processing. REPORT is valuable in
cases where the server has access to all of the information
needed to perform the complex request (such as a query), and
where it would require multiple requests for the client to
retrieve the information needed to perform the same request.
CalDAV servers MUST support the DAV:expand-property REPORT
defined in Section 3.8 of .
Servers MAY support the REPORTs defined in this document on
ordinary collections (collections that are not calendar
collections) in addition to calendar collections or calendar
object resources. In computing responses to the REPORTs on
ordinary collections, servers MUST only consider calendar object
resources contained in calendar collections that are targeted by
the REPORT based on the value of the Depth request header.
iCalendar provides a way to specify DATE and DATE-TIME values
that are not bound to any time zone in particular, hereafter
called "floating date" and "floating time" respectively. These
values are used to represent the same day, hour, minute and
second value regardless of which time zone is being observed.
For instance, the DATE value "20051111", represents November 11th,
2005 in no specific time zone, while the DATE-TIME value
"20051111T111100" represents November 11th, 2005 at 11:11 AM in
no specific time zone.
CalDAV servers may need to convert "floating date" and "floating
time" values in date with UTC time values in the processing
of calendaring REPORT requests.
For the CALDAV:calendar-query REPORT, CalDAV servers MUST rely
on the value of the CALDAV:timezone XML element, if specified
as part of the request body, to perform the proper conversion
of "floating date" and "floating time" values to date with UTC
time values. If the CALDAV:timezone XML element is not specified
in the request body, CalDAV servers MUST rely on the value of
the CALDAV:calendar-timezone property, if defined, else the
CalDAV servers MAY rely on the time zone of their choice.
For the CALDAV:free-busy-query REPORT, CalDAV servers MUST rely
on the value of the CALDAV:calendar-timezone property, if defined,
to compute the proper FREEBUSY time period value as date with UTC
time, for calendar components scheduled with "floating date" or
"floating time". If the CALDAV:calendar-timezone property is not
defined, CalDAV servers MAY rely on the time zone of their choice.
Some of the reports defined in this section can include a time
range filter that is used to restrict the set of calendar object
resources returned to just those that overlap the specified time
range. The time range filter can be applied to a calendar
component as a whole, or to specific calendar component
properties with date or date-time value types.
To determine whether a calendar object resource matches the time
range filter element, the start and end times for the targeted
component or property are determined and then compared to the
requested time range. If there is an overlap with the requested
time range, then the calendar object resource matches the filter
element. The rules defined in for
determining the actual start and end times of calendar components
MUST be used, and these are fully enumerated in
of this document.
When such time range filtering is used, special consideration must
be given to recurring calendar components such as VEVENT and
VTODO components. The server MUST expand recurring components to
determine whether any recurrence instances overlap the specified
time range. If one or more recurrence instances overlap the time
range, then the calendar object resource matches the filter element.
Some calendaring REPORTs defined in this document allow partial
retrieval of calendar object resources. A CalDAV client MAY specify
what information to return in the body of a calendaring REPORT
request.A CalDAV client MAY request particular WebDAV property values,
all WebDAV property values, or a list of the names of the
resource's WebDAV properties. A CalDAV client MAY also request
calendar data to be returned and whether all calendar components
and properties should be returned or only particular ones. See
CALDAV:calendar-data in .By default, the returned calendar data will include the
component that defines the recurrence set, referred to as the
"master component", as well as the components that define
exceptions to the recurrence set, referred to as the "overridden
components".A CalDAV client only interested in the recurrence instances that
overlap a specified time range MAY request to receive only the
"master component" along with the "overridden components" that
impact the specified time range and thus limit the data returned by
the server. See CALDAV:limit-recurrence-set in . An overridden component
impacts a time range if its current start and end times overlap the
time range, or if the original start and end times - the ones that
would have been used if the instance were not overridden - overlap
the time range.A CalDAV client with no support for recurrence properties (i.e.,
EXDATE, EXRULE, RDATE and RRULE) and possibly VTIMEZONE components,
or a client not willing to perform recurrence expansion because
of limited processing capability MAY request to receive only the
recurrence instances that overlap a specified time range as
separate calendar components that each define exactly one
recurrence instance. See CALDAV:expand in .Finally, in the case of VFREEBUSY components, a CalDAV client
MAY request to receive only the FREEBUSY property values that
overlap a specified time range. See CALDAV:limit-freebusy-set in
.
Servers MUST support the use of non-standard component,
property or parameter names in the CALDAV:calendar-data XML element
in calendaring REPORT requests to allow clients to request that
non-standard components, properties and parameters be returned
in the calendar data provided in the response.
Servers MAY support the use of non-standard component, property
or parameter names in the CALDAV:comp-filter, CALDAV:prop-filter and
CALDAV:param-filter XML elements specified in the CALDAV:filter
XML element of calendaring REPORT requests.
Servers MUST fail with the CALDAV:supported-filter precondition if
a calendaring REPORT request uses a CALDAV:comp-filter,
CALDAV:prop-filter or CALDAV:param-filter XML element that makes
reference to a non-standard component, property or parameter name
which the server does not support queries on.
The CALDAV:calendar-query REPORT performs a search for all
calendar object resources that match a specified filter.
The response of this REPORT will contain all the WebDAV
properties and calendar object resource data specified in the
request. In the case of the CALDAV:calendar-data XML element,
one can explicitly specify the calendar components and properties
that should be returned in the calendar object resource data
that matches the filter.
The format of this REPORT is modeled on the PROPFIND method.
The request and response bodies of the CALDAV:calendar-query
REPORT use XML elements that are also used by PROPFIND. In
particular the request can include XML elements to request
WebDAV properties to be returned. When that occurs the
response should follow the same behavior as PROPFIND with
respect to the DAV:multistatus response elements used to
return specific property results. For instance, a request
to retrieve the value of a property which does not exist
is an error and MUST be noted with a response XML element
which contains a 404 (Not Found) status value.
Support for the CALDAV:calendar-query REPORT is REQUIRED.
Marshalling:
The request body MUST be a CALDAV:calendar-query XML
element as defined in .
The request MAY include a Depth header. If no Depth header
is included, Depth:0 is assumed.
The response body for a successful request MUST be a
DAV:multistatus XML element (i.e., the response uses the
same format as the response for PROPFIND). In the case
where there are no response elements, the returned
DAV:multistatus XML element is empty.
The response body for a successful CALDAV:calendar-query
REPORT request MUST contain a DAV:response element
for each iCalendar object that matched the search
filter. Calendar data is being returned in the
CALDAV:calendar-data XML element inside the
DAV:propstat XML element.
Preconditions:
(CALDAV:supported-calendar-data): The attributes
"content-type" and "version" of the CALDAV:calendar-data
XML element (see ) specify a media type supported by the server
for calendar object resources.
(CALDAV:valid-filter): The CALDAV:filter XML element (see )
specified in the REPORT request MUST be valid.
For instance, a CALDAV:filter cannot nest a
]]> element in a
]]> element, or a
CALDAV:filter cannot nest a
]]>
element in a
]]> element.
(CALDAV:supported-filter): The CALDAV:comp-filter (see ), CALDAV:prop-filter (see ) and CALDAV:param-filter (see
) XML elements used in
the CALDAV:filter XML element (see ) in the REPORT request only make
reference to components, properties and parameters for which
queries are supported by the server. i.e., if the
CALDAV:filter element attempts to reference an unsupported
component, property or parameter, this precondition is
violated. Servers SHOULD report the CALDAV:comp-filter,
CALDAV:prop-filter or CALDAV:param-filter for which it does
not provide support.
]]>
(CALDAV:valid-calendar-data): The time zone specified in
the REPORT request MUST be a valid
iCalendar object containing a single valid VTIMEZONE component.
(CALDAV:min-date-time): Any XML element specifying a range of
time MUST have its start or end date or time
values greater than or equal to
the value of the CALDAV:min-date-time property value
() on the calendar collections
being targeted by the REPORT;
(CALDAV:max-date-time): Any XML element specifying a range of
time MUST have its start or end date or time
values less than or equal to
the value of the CALDAV:max-date-time property value
() on the calendar collections
being targeted by the REPORT;
Postconditions:
(DAV:number-of-matches-within-limits): The number of matching
calendar object resources must fall within server-specific,
predefined limits. For example, this condition might be
triggered if a search specification would cause the return
of an extremely large number of responses.
In this example, the client requests the server to
return specific components and properties of the VEVENT
components that overlap the time range from January
4th, 2006 at 00:00:00 AM UTC to January 5th, 2006 at
00:00:00 AM UTC. In addition the DAV:getetag
property is also requested and returned as part of the
response. Note that the first calendar object returned is a
recurring event whose first instance lies outside of the requested
time range, but whose third instance does overlap the time range.
Note that due to the CALDAV:calendar-data element restrictions, the
DTSTAMP property in VEVENT components has not been returned, and
the only property returned in the VCALENDAR object is VERSION.
See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd2.ics"fffff-abcd2"BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=US/Eastern:20060102T120000
DURATION:PT1H
RRULE:FREQ=DAILY;COUNT=5
SUMMARY:Event #2
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=US/Eastern:20060104T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060104T120000
SUMMARY:Event #2 bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=US/Eastern:20060106T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060106T120000
SUMMARY:Event #2 bis bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=US/Eastern:20060104T100000
DURATION:PT1H
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OK
]]>
In this example, the client requests the server to
return VEVENT components that overlap the time range
from January 3rd, 2006 at 00:00:00 AM UTC to January 5th, 2006
at 00:00:00 AM UTC. Use of the CALDAV:limit-recurrence-set
element causes the server to only return overridden
recurrence components that overlap the time range specified
in that element, or that affect other instances that overlap the time
range (e.g., in the case of a "THISANDFUTURE" behavior). In this example
the first overridden component in the matching resource is returned but
the second one is not.
See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd2.ics"fffff-abcd2"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060102T120000
DURATION:PT1H
RRULE:FREQ=DAILY;COUNT=5
SUMMARY:Event #2
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060104T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060104T120000
SUMMARY:Event #2 bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;PARTSTAT=ACCEPTED;ROLE=CHAIR:mailto:cyrus@example.com
ATTENDEE;PARTSTAT=NEEDS-ACTION:mailto:lisa@example.com
DTSTAMP:20060206T001220Z
DTSTART;TZID=US/Eastern:20060104T100000
DURATION:PT1H
LAST-MODIFIED:20060206T001330Z
ORGANIZER:mailto:cyrus@example.com
SEQUENCE:1
STATUS:TENTATIVE
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
X-ABC-GUID:E1CX5Dr-0007ym-Hz@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OK
]]>
In this example, the client requests the server to
return VEVENT components that overlap the time range
from January 2nd, 2006 at 00:00:00 AM UTC to January 5th, 2006
at 00:00:00 AM UTC and to return recurring calendar
components expanded into individual recurrence instance
calendar components. Use of the CALDAV:expand
element causes the server to only return overridden recurrence
instances that overlap the time range specified in that element.
See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd2.ics"fffff-abcd2"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART:20060103T170000
DURATION:PT1H
RECURRENCE-ID:20060103T170000
SUMMARY:Event #2
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART:20060104T190000
DURATION:PT1H
RECURRENCE-ID:20060104T170000
SUMMARY:Event #2 bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VEVENT
ATTENDEE;PARTSTAT=ACCEPTED;ROLE=CHAIR:mailto:cyrus@example.com
ATTENDEE;PARTSTAT=NEEDS-ACTION:mailto:lisa@example.com
DTSTAMP:20060206T001220Z
DTSTART:20060104T150000
DURATION:PT1H
LAST-MODIFIED:20060206T001330Z
ORGANIZER:mailto:cyrus@example.com
SEQUENCE:1
STATUS:TENTATIVE
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
X-ABC-GUID:E1CX5Dr-0007ym-Hz@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OK
]]>
In this example, the client requests the server to
return the VFREEBUSY components that have free busy
information that overlap the time range from January 2nd,
2006 at 00:00:00 AM UTC (inclusively) to January 3rd, 2006
at 00:00:00 AM UTC (exclusively). Use of the
CALDAV:limit-freebusy-set element causes the server
to only return the FREEBUSY property values that
overlap the time range specified in that element.
Note that this is not an example of discovering when
the calendar owner is busy.
See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd8.ics"fffff-abcd8"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VFREEBUSY
ORGANIZER;CN="Bernard Desruisseaux":mailto:bernard@example.com
UID:76ef34-54a3d2@example.com
DTSTAMP:20050530T123421Z
DTSTART:20060101T100000Z
DTEND:20060108T100000Z
FREEBUSY;FBTYPE=BUSY-TENTATIVE:20060102T100000Z/20060102T120000Z
END:VFREEBUSY
END:VCALENDAR
HTTP/1.1 200 OK
]]> In this example, the client requests the server to
return the VTODO components that have an alarm trigger
scheduled in the specified time range. See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd4.ics"fffff-abcd4"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
DTSTAMP:20060205T235300Z
DUE;TZID=US/Eastern:20060106T120000
LAST-MODIFIED:20060205T235308Z
SEQUENCE:1
STATUS:NEEDS-ACTION
SUMMARY:Task #2
UID:E10BA47467C5C69BB74E8720@example.com
BEGIN:VALARM
ACTION:AUDIO
TRIGGER;RELATED=START:-PT10M
END:VALARM
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OK
]]> In this example, the client requests the server to
return the VEVENT component that has the UID property
set to "DC6C50A017428C5216A2F1CD@example.com". See for the calendar data being targeted by this example.>> Request <<
DC6C50A017428C5216A2F1CD@example.com
]]>>> Response <<http://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;PARTSTAT=ACCEPTED;ROLE=CHAIR:mailto:cyrus@example.com
ATTENDEE;PARTSTAT=NEEDS-ACTION:mailto:lisa@example.com
DTSTAMP:20060206T001220Z
DTSTART;TZID=US/Eastern:20060104T100000
DURATION:PT1H
LAST-MODIFIED:20060206T001330Z
ORGANIZER:mailto:cyrus@example.com
SEQUENCE:1
STATUS:TENTATIVE
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
X-ABC-GUID:E1CX5Dr-0007ym-Hz@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OK
]]> In this example, the client requests the server to
return the VEVENT components that have the ATTENDEE
property with the value "mailto:lisa@example.com" and
for which the PARTSTAT parameter is set to
"NEEDS-ACTION". See for the calendar data being targeted by this example.>> Request <<mailto:lisa@example.comNEEDS-ACTION
]]>>> Response <<http://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;PARTSTAT=ACCEPTED;ROLE=CHAIR:mailto:cyrus@example.com
ATTENDEE;PARTSTAT=NEEDS-ACTION:mailto:lisa@example.com
DTSTAMP:20060206T001220Z
DTSTART;TZID=US/Eastern:20060104T100000
DURATION:PT1H
LAST-MODIFIED:20060206T001330Z
ORGANIZER:mailto:cyrus@example.com
SEQUENCE:1
STATUS:TENTATIVE
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
X-ABC-GUID:E1CX5Dr-0007ym-Hz@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OK
]]> In this example, the client requests the server to
return all VEVENT components. See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd1.ics"fffff-abcd1"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001102Z
DTSTART;TZID=US/Eastern:20060102T100000
DURATION:PT1H
SUMMARY:Event #1
Description:Go Steelers!
UID:74855313FA803DA593CD579A@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd2.ics"fffff-abcd2"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060102T120000
DURATION:PT1H
RRULE:FREQ=DAILY;COUNT=5
SUMMARY:Event #2
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060104T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060104T120000
SUMMARY:Event #2 bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060106T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060106T120000
SUMMARY:Event #2 bis bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;PARTSTAT=ACCEPTED;ROLE=CHAIR:mailto:cyrus@example.com
ATTENDEE;PARTSTAT=NEEDS-ACTION:mailto:lisa@example.com
DTSTAMP:20060206T001220Z
DTSTART;TZID=US/Eastern:20060104T100000
DURATION:PT1H
LAST-MODIFIED:20060206T001330Z
ORGANIZER:mailto:cyrus@example.com
SEQUENCE:1
STATUS:TENTATIVE
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
X-ABC-GUID:E1CX5Dr-0007ym-Hz@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OK
]]>
In this example, the client requests the server to return all
VTODO components that do not include a "COMPLETED" property and
do not have a "STATUS" property value matching "CANCELLED".
i.e., VTODOs that still need to be worked on.
See for the calendar data being targeted by this example.>> Request <<CANCELLED
]]>>> Response <<http://cal.example.com/bernard/work/abcd4.ics"fffff-abcd4"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
DTSTAMP:20060205T235335Z
DUE;VALUE=DATE:20060104
STATUS:NEEDS-ACTION
SUMMARY:Task #1
UID:DDDEEB7915FA61233B861457@example.com
BEGIN:VALARM
ACTION:AUDIO
TRIGGER;RELATED=START:-PT10M
END:VALARM
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd5.ics"fffff-abcd5"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
DTSTAMP:20060205T235300Z
DUE;VALUE=DATE:20060106
LAST-MODIFIED:20060205T235308Z
SEQUENCE:1
STATUS:NEEDS-ACTION
SUMMARY:Task #2
UID:E10BA47467C5C69BB74E8720@example.com
BEGIN:VALARM
ACTION:AUDIO
TRIGGER;RELATED=START:-PT10M
END:VALARM
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OK
]]> In this example, the client requests the server to
return all VEVENT components that include an "X-ABC-GUID" property
with a value matching "ABC". However, the server does not support
querying that non-standard property and instead returns and error
response.See for the calendar data being targeted by this example.>> Request <<ABC
]]>>> Response <<
]]>
The CALDAV:calendar-multiget REPORT is used to retrieve specific
calendar object resources from within a collection, if the
Request-URI is a collection, or to retrieve a specific
calendar object resource, if the Request-URI is a calendar
object resource. This REPORT is similar to the CALDAV:calendar-query
REPORT (see ), except that it takes
a list of DAV:href elements instead of a CALDAV:filter element to
determine which calendar object resources to return.
Support for the calendar-multiget REPORT is REQUIRED.
Marshalling:
The request body MUST be a CALDAV:calendar-multiget XML
element (see ). If
the Request-URI is a collection resource, then the DAV:href
elements MUST refer to calendar object resources within that
collection, and they MAY refer to calendar object resources
at any depth within the collection. As a result the "Depth"
header MUST be ignored by the server and SHOULD NOT be sent
by the client. If the Request-URI refers to a non-collection
resource, then there MUST be a single DAV:href element that
is equivalent to the Request-URI.
The response body for a successful request MUST be a
DAV:multistatus XML element.
The response body for a successful CALDAV:calendar-multiget
REPORT request MUST contain a DAV:response element
for each calendar object resource referenced by the
provided set of DAV:href elements. Calendar data is
being returned in the CALDAV:calendar-data element
inside the DAV:prop element.
In the case of an error accessing any of the provided
DAV:href resources, the server MUST return the appropriate
error status code in the DAV:status element of the
corresponding DAV:response element.
Preconditions:
(CALDAV:supported-calendar-data): The attributes
"content-type" and "version" of the CALDAV:calendar-data
XML elements (see ) specify a media type supported by the
server for calendar object resources.
(CALDAV:min-date-time): Any XML element specifying a range of
time MUST have its start or end date or time
values greater than or equal to
the value of the CALDAV:min-date-time property value
() on the calendar collections
being targeted by the REPORT;
(CALDAV:max-date-time): Any XML element specifying a range of
time MUST have its start or end date or time
values less than or equal to
the value of the CALDAV:max-date-time property value
() on the calendar collections
being targeted by the REPORT;
Postconditions:
None.
In this example, the client requests the server to
return specific properties of the VEVENT components
referenced by specific URIs. In addition the
DAV:getetag property is also requested and returned as
part of the response. Note that in this example, the
resource at
http://cal.example.com/bernard/work/mtg1.ics
does not exist, resulting in an error status response.
See for the calendar data being targeted by this example.>> Request <</bernard/work/abcd1.ics/bernard/work/mtg1.ics
]]>>> Response <<http://cal.example.com/bernard/work/abcd1.ics"fffff-abcd1"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001102Z
DTSTART;TZID=US/Eastern:20060102T100000
DURATION:PT1H
SUMMARY:Event #1
Description:Go Steelers!
UID:74855313FA803DA593CD579A@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/mtg1.icsHTTP/1.1 404 Not Found
]]>
The CALDAV:free-busy-query REPORT generates a VFREEBUSY
component containing free busy information for all the
calendar object resources targeted by the request and
which have the CALDAV:read-free-busy or DAV:read privilege
granted to the current user.
Only VEVENT components without a TRANSP property or with the
TRANSP property set to "OPAQUE", and VFREEBUSY components
SHOULD be considered to generate the free busy time information.
In the case of VEVENT components, the free or busy time type
(FBTYPE) of the FREEBUSY properties in the returned VFREEBUSY
component SHOULD be derived from the value of the TRANSP and
STATUS properties as outlined in the table below:
+---------------------------++------------------+
| VEVENT || VFREEBUSY |
+-------------+-------------++------------------+
| TRANSP | STATUS || FBTYPE |
+=============+=============++==================+
| | CONFIRMED || BUSY |
| | (default) || |
| OPAQUE +-------------++------------------+
| (default) | CANCELLED || FREE |
| +-------------++------------------+
| | TENTATIVE || BUSY-TENTATIVE |
| +-------------++------------------+
| | x-name || BUSY or |
| | || x-name |
+-------------+-------------++------------------+
| | CONFIRMED || |
| TRANSPARENT | CANCELLED || FREE |
| | TENTATIVE || |
| | x-name || |
+-------------+-------------++------------------+
Duplicate busy time periods with the same FBTYPE parameter
value SHOULD NOT be specified in the returned VFREEBUSY
component. Servers SHOULD coalesce consecutive or overlapping
busy time period of the same type. Busy time periods with
different FBTYPE parameter values MAY overlap.
Support for the CALDAV:free-busy-query REPORT is REQUIRED.
Marshalling:
The request body MUST be a CALDAV:free-busy-query XML
element (see ,
which MUST contain exactly one CALDAV:time-range XML
element, as defined in .
The request MAY include a Depth header. If no Depth header
is included, Depth:0 is assumed.
The response body for a successful request MUST be an
iCalendar object that contains exactly one VFREEBUSY
component that describes the busy time intervals for the
calendar object resources containing VEVENT or VFREEBUSY
components that satisfy the Depth value and for which the
current user is at least granted the CALDAV:read-free-busy
privilege. If no calendar object resources are found to
satisfy these conditions a VFREEBUSY component with no
FREEBUSY property MUST be returned. This REPORT only
returns busy time information. Free time information can
be inferred from the returned busy time information.
If the current user is not granted the CALDAV:read-free-busy or
DAV:read privileges on the Request-URI, the CALDAV:free-busy-query
REPORT request MUST fail and return a 404 (Not Found) status
value. This restriction will prevent users from discovering
URLs of resources for which they are only granted the
CALDAV:read-free-busy privilege.
The CALDAV:free-busy-query REPORT request can only be run against
a collection (either a regular collection or a calendar collection).
An attempt to run the report on a calendar object resource MUST fail
and return a 403 (Forbidden) status value.
Preconditions:
None.
Postconditions:
(DAV:number-of-matches-within-limits): The number of matching
calendar object resources must fall within server-specific,
predefined limits. For example, this postcondition might fail
if the specified CALDAV:time-range would cause an extremely
large number calendar object resources to be considered to
compute the response.
In this example, the client requests the server to
return free busy information on the calendar collection
/bernard/work/, between 9:00 AM and 5:00 PM EST (2:00 PM
and 10:00 PM UTC) on the 4th
January 2006. The server responds indicating two
busy time intervals of one hour, one of which is tentative.See for the calendar data being targeted by this example.>> Request <<
]]>>> Response <<
There are a number of actions clients can take which will be
legal (the server will not return errors) but which can degrade
interoperability with other client implementations accessing
the same data. For example, a recurrence rule could be replaced
with a set of recurrence dates, a single recurring event could
be replaced with a set of independent resources to represent
each recurrence, or the start/end time values can be translated
from the original time zone to another time zone. Although this
advice amounts to iCalendar interoperability best practices and
is not limited only to CalDAV usage, interoperability problems are
likely to be more evident in CalDAV use cases.
WebDAV already provides functionality required to synchronize a
collection or set of collections, make changes offline, and a
simple way to resolve conflicts when reconnected. ETags
are the key to making this work, but these are not required of
all WebDAV servers. Since offline functionality is more
important to calendar applications than to some other WebDAV
applications, CalDAV servers MUST support ETags as specified
in .
The REPORTs provided in CalDAV can be used by clients to
optimize their performance in terms of network bandwidth
usage, and resource consumption on the local client machine.
Both are certainly major considerations for mobile or handheld
devices with limited capacity, but they are also relevant to
desktop client applications in cases where the calendar
collections contain large amounts of data.
Typically clients present calendar data to users in
views that span a finite time interval, so whenever
possible clients should only retrieve calendar components
from the server using CALDAV:calendar-query REPORT combined
with a CALDAV:time-range element to limit the set of
returned components to just those needed to populate the
current view.
Typically in a calendar, historical data (events, to-dos
etc. that have completed prior to the current date) do
not change, though they may be deleted. As a result, a
client can speed up the synchronization process by only
considering data for the present time and the future
up to a reasonable limit (e.g., one week, one month). If
the user then tries to examine a portion of the
calendar outside of the range that has been
synchronized, the client can perform another
synchronization operation on the new time interval being
examined. This "just-in-time" synchronization can
minimize bandwidth for common user interaction
behaviors.
If a client wants to support calendar data synchronization,
as opposed to downloading calendar data each time it is needed,
it needs to cache the calendar object resource's URI and ETag
along with the actual calendar data. While the URI remains
static for the lifetime of the calendar object resource, the
ETag will change with each successive change to the calendar
object resource. Thus to synchronize a local data cache with
the server, the client can first fetch the URI/ETag pairs for
the time interval being considered, and compare those results
with the cached data. Any cached component whose ETag differs
from that on the server needs to be refreshed.
In order to properly detect the changes between the server and
client data, the client will need to keep a record of which
calendar object resources have been created, changed or deleted
since the last synchronization operation so that it can reconcile
those changes with the data on the server.
Here's an example of how to do that:
The client issues a CALDAV:calendar-query REPORT request
for a specific time range, and asks for only the
DAV:getetag property to be returned:
]]>
The client then uses the results to determine which calendar
object resources have changed, been created or deleted on
the server and how those relate to locally cached calendar
object resources that may have changed, been created or
deleted. If the client determines that there are calendar
object resources on the server that need to be fetched,
the client issues a CALDAV:calendar-multiget REPORT request
to fetch their calendar data:
/bernard/work/abcd1.ics/bernard/work/mtg1.ics
]]>
Clients may not need all the calendar properties of a calendar
object resource when presenting information to the user. Since
some calendar property values can be large (e.g., ATTACH or
ATTENDEE) clients can choose to restrict the
calendar properties to be returned in a calendaring REPORT
request to those it knows it will use.
However, if a client needs to make a change to a calendar object
resource, it can only change the entire calendar object resource
via a PUT request. There is currently no way to incrementally make
a change to a set of calendar properties of a calendar object
resource. As a result the client will have to get the entire
calendar object resource that is being changed.
WebDAV locks can be used to prevent two clients modifying the
same resource from either overwriting each others' changes
(though that problem can also be solved by using ETags) or
wasting time making changes that will conflict
with another set of changes. In a multi-user calendar system,
an interactive calendar client could lock an event while the user is
editing the event, and unlock the event when the user finishes
or cancels. Locks can also be used to prevent changes while
data is being reorganized. For example, a calendar client
might lock two calendar collections prior to moving a bunch
of calendar resources from one to another.
Clients are responsible for requesting a lock timeout period that
is appropriate
to the use case. When the user explicitly decides to reserve
a resource and prevent other changes, a long timeout might be
appropriate, but in cases when the client automatically decides
to lock the resource the timeout should be short (and the client
can always refresh the lock should it need to). A short lock
timeout means that if the client is unable to remove the lock,
the other calendar users aren't prevented from making changes.
Much of the time a calendar client (or agent) will discover
a new calendar's location by being provided directly with the
URL. E.g., a user will type his or her own calendar location into
client configuration information, or copy and paste a URL from
email into the calendar application. The client need only confirm
that the URL points to a resource which is a calendar collection.
The client may also be able to browse WebDAV collections to find
calendar collections.
The choice of HTTP URLs means that calendar object resources are
backward compatible with existing software, but does have the
disadvantage that existing software does not usually know to look at
the OPTIONS response to that URL to determine what can be done with it.
This is somewhat of a barrier for WebDAV usage as well as with CalDAV
usage. This specification does not offer a way through this other than
making the information available in the OPTIONS response should this
be requested.
For calendar sharing and scheduling use cases, one might wish to
find the calendar belonging to another user. If the other user has
a calendar in the same repository, that calendar can be found by
using the principal namespace required by WebDAV ACL support.
For other cases, the authors have no universal solution but
implementers can consider whether to use
vCard or
LDAP standards together with
calendar attributes.
Because CalDAV requires servers to support
WebDAV ACL including principal namespaces, and with the
addition of the CALDAV:calendar-home-set property, there are a
couple options for CalDAV clients to find one's own calendar or
another user's calendar.
In this case, a DAV:principal-match REPORT is used to find a named
property (the CALDAV:calendar-home-set) on the Principal-URL of the
current user. Using this, a WebDAV client can learn "who am I" and
"where are my calendars". The REPORT request body looks like this:
]]>
To find other users calendars, the DAV:principal-property-search
REPORT can be used to filter on some properties and return
others. To search for a calendar owned by a user named "Laurie",
the REPORT request body would look like this:
Laurie
]]>
The server performs a case-sensitive or caseless search for a
matching string subset of "Laurie" within the DAV:displayname
property. Thus, the server might return "Laurie Dusseault",
"Laurier Desruisseaux" or "Wilfrid Laurier" all as matching
DAV:displayname values, and the calendars for each of these.
CalDAV clients MAY create attachments in calendar components either
as inline or external. This section contains some guidelines on
creating and managing attachments.
CalDAV clients MUST support inline attachments as specified in
iCalendar. CalDAV servers MUST
support inline attachments, so clients can rely on being able
to create attachments this way. On the other hand, inline
attachments have some drawbacks:
Servers MAY impose limitations on the size of calendar
object resources (i.e., refusing PUT requests of very
large iCalendar objects). Servers that do that MUST use
the CALDAV:max-resource-size property on a calendar
collection to inform the client as to what the limitation
is (see .
Servers MAY impose storage quota limitations on calendar
collections (See ).
Any change to a calendar object resource containing an
attachment requires the entire attachment to be
re-uploaded.
Clients synchronizing a changed calendar object resource
have to download the entire calendar object resource even
if the attachment is unchanged.
CalDAV clients MUST support external attachments: if the client
accesses any calendar object resource it MUST be capable of also
accessing the external attachment if one exists. An external
attachment could be:
In a collection in the calendar collection containing
the calendar object resource;
Somewhere else in the same repository that hosts the
calendar collection; or
On an HTTP or FTP server elsewhere.
CalDAV servers MAY provide support for child collections in
calendar collections. CalDAV servers MAY allow the MKCOL
method to create child collections in calendar collections.
Child collections of calendar collections MAY contain any
type of resource except calendar collections which they MUST
NOT contain. Some CalDAV servers won't allow child collections
in calendar collections, and it may be possible on such a
server to discover other locations where attachments can be
stored.
Clients are entirely responsible for maintaining reference
consistency with calendar components that link to external
attachments. A client deleting a calendar component with an
external attachment might therefore also delete the attachment
if that's appropriate, however appropriateness can be very hard
to determine. A new component might easily reference some
pre-existing Web resource which is intended to have
independent existence from the calendar component (the
"attachment" could be a major proposal to be discussed
in a meeting, for instance). Best practices will probably
emerge and should probably be documented but for now clients
should be wary of engaging in aggressive "cleanup" of external
attachments. A client could involve the user in making
decisions about removing unreferenced documents, or a client
could be conservative in only deleting attachments it had
created.
Also, clients are responsible for consistency of permissions
when using external attachments. One reason for servers to
support the storage of attachments within child collections of
calendar collections is that ACL inheritance might make it
easier to grant the same permissions to attachments that are
granted on the calendar collection. Otherwise, it can be very
difficult to keep permissions synchronized. With attachments
stored on separate repositories, it can be impossible to keep
permissions consistent -- the two repositories may not support
the same permissions or have the same set of principals. Some
systems have used tickets or other anonymous access control
mechanisms to provide partially satisfactory solutions to these
kinds of problems.
Note that all CalDAV calendar collections (including those
which the user might treat as public or group calendars) can
contain alarm information on events and to-dos. Users can
synchronize a calendar between multiple devices and decide
to have alarms execute on a different device than the device
that created the alarm. Not all alarm action types are completely
interoperable (e.g., those which name a sound file to play).
When the action is "AUDIO", and the client is configured to
execute the alarm, the client SHOULD play the suggested
sound if it's available or play another sound, but SHOULD NOT
rewrite the alarm just to replace the suggested sound with
a sound that's locally available.
When the action is "DISPLAY", and the client is configured to
execute the alarm, the client SHOULD execute a display alarm by
displaying either according to the suggested description or
some reasonable replacement, but SHOULD NOT rewrite the alarm
for its own convenience.
When the action is "EMAIL", and the client is incapable of
sending email, it SHOULD ignore the alarm but MUST continue
to synchronize the alarm itself.
This specification makes no recommendations about executing
alarm of type PROCEDURE except to note that clients are
advised to take care to avoid creating security holes by
executing these.
Non-interoperable alarm information (e.g., should somebody define
a color to be used in a display alarm) should be put in non-standard
properties inside the VALARM component in order to keep the basic
alarm usable on all devices.
Clients that allow changes to calendar object resources MUST
synchronize the alarm data that already exists in the resources.
Clients MAY execute alarms that are downloaded in this fashion,
possibly based on user preference. If a client is only doing
read operations on a calendar and there is no risk of losing
alarm information, then the client MAY discard alarm information.
This specification makes no attempt to provide multi-user alarms
on group calendars or to find out who an alarm is intended for.
Addressing those issues might require extensions to iCalendar,
for example to store alarms per-user or indicate which user a
VALARM was intended for. In the meantime, clients might maximize
interoperability by generally not uploading alarm information to
public, group or resource calendars.
calendar
urn:ietf:params:xml:ns:caldav
Specifies the resource type of a calendar collection.
See .
]]>
mkcalendar
urn:ietf:params:xml:ns:caldav
Specifies a request that includes the WebDAV property values
to be set for a calendar collection resource when it is created.
See .
]]>
mkcalendar-response
urn:ietf:params:xml:ns:caldav
Specifies a response body for a successful MKCALENDAR request.
See .
]]>
calendar-query
urn:ietf:params:xml:ns:caldav
Defines a REPORT for querying calendar object resources.
See .
]]>
calendar-data
urn:ietf:params:xml:ns:caldav
Used to
(1) specify a supported media type for
calendar object resources when nested in the
CALDAV:supported-calendar-data property;
(2) specify which parts of a calendar object resource
should be returned by a given calendaring REPORT; and
(3) specify the content of a calendar object resource
in a response to a calendaring REPORT.
When nested in the CALDAV:supported-calendar-data property,
the CALDAV:calendar-data XML element specifies a media type
supported by the CalDAV server for calendar object resources.
When used in a calendaring REPORT request, the
CALDAV:calendar-data XML element specifies which parts
of calendar object resources need to be returned in the
response. If the CALDAV:calendar-data XML element doesn't
contain any CALDAV:comp element, calendar object resources
will be returned in their entirety.
Finally, when used in a calendaring REPORT response, the
CALDAV:calendar-data XML element specifies the content of
a calendar object resource. Given that XML parsers normalize
the two-character sequence CRLF (US-ASCII decimal 13 and
US-ASCII decimal 10) to a single LF character (US-ASCII
decimal 10), the CR character (US-ASCII decimal 13) MAY be
omitted in calendar object resources specified in the
CALDAV:calendar-data XML element. Furthermore, calendar
object resources specified in the CALDAV:calendar-data XML
element MAY be invalid per their media type specification
if the CALDAV:calendar-data XML element part of the
calendaring REPORT request did not specify required properties
(e.g., UID, DTSTAMP, etc.) or specified a CALDAV:prop XML
element with the "novalue" attribute set to "yes".
The CALDAV:calendar-data XML element is specified in
requests and responses inside the DAV:prop XML element
as if it were a WebDAV property. However, the
CALDAV:calendar-data XML element is not a WebDAV
property and as such it is not returned in PROPFIND
responses nor used in PROPPATCH requests.
The iCalendar data embedded within the CALDAV:calendar-data XML
element MUST follow the standard XML character data encoding rules,
including use of <, >, & etc entity encoding
or the use of a <[!CDATA[ ... ]]> construct. In the later case
the iCalendar data cannot contain the character sequence "]]>"
which is the end delimiter for the CDATA section.
PCDATA value: iCalendar object
version CDATA "2.0">
content-type value: a MIME media type
version value: a version string
]]>
comp
urn:ietf:params:xml:ns:caldav
Defines which component types to return.
The name value is a calendar component name
(e.g., "VEVENT").
name value: a calendar component name
]]>
The CALDAV:prop and CALDAV:allprop elements have
the same name as the DAV:prop and DAV:allprop
elements defined in .
However, the CALDAV:prop and CALDAV:allprop element
are defined in the "urn:ietf:params:xml:ns:caldav"
namespace instead of the "DAV:" namespace.
allcomp
urn:ietf:params:xml:ns:caldav
Specifies that all components shall be returned.
The CALDAV:allcomp XML element can be used when the
client wants all types of components returned by a
calendaring REPORT request.
]]>
allprop
urn:ietf:params:xml:ns:caldav
Specifies that all properties shall be returned.
The CALDAV:allprop XML element can be used when the client
wants all properties of components returned by a
calendaring REPORT request.
]]>
The CALDAV:allprop element has the same name as the
DAV:allprop element defined in .
However, the CALDAV:allprop element is defined in the
"urn:ietf:params:xml:ns:caldav" namespace instead of
the "DAV:" namespace.
prop
urn:ietf:params:xml:ns:caldavDefines which
properties to return in the
response.The "name"
attribute specifies the name of the
calendar property to return (e.g.,
"ATTENDEE"). The "novalue" attribute
can be used by clients to request that
the actual value of the property not be
returned (if the "novalue" attribute is
set to "yes"). In that case the server
will return just the iCalendar property
name and any iCalendar parameters and a
trailing ":" without the subsequent
value data.
name value: a calendar property name
novalue value: "yes" or "no"
]]>
The CALDAV:prop element has the same name as the
DAV:prop element defined in .
However, the CALDAV:prop element is defined in the
"urn:ietf:params:xml:ns:caldav" namespace instead of
the "DAV:" namespace.
expand
urn:ietf:params:xml:ns:caldav
Forces the server to expand recurring components
into individual recurrence instances.
The CALDAV:expand XML element specifies that for
a given calendaring REPORT request the server MUST
expand the recurrence set into calendar components
that define exactly one recurrence instance and MUST
return only those whose scheduled time intersect a
specified time range.
The "start" attribute specifies the inclusive start of
the time range, and the "end" attribute specifies the
non-inclusive end of the time range. Both attributes are
specified as date with UTC time value. The value of the
"end" attribute MUST be greater than the value of the
"start" attribute.
The server MUST use the same logic as defined for
CALDAV:time-range to determine if a recurrence
instance intersects the specified time range.
Recurring components, other than the initial instance, MUST
include a RECURRENCE-ID property indicating which instance they
refer to.
The returned calendar components MUST NOT use
recurrence properties (i.e., EXDATE, EXRULE, RDATE
and RRULE) and MUST NOT have reference to or include
VTIMEZONE components. Date and local time with reference
to time zone information MUST be converted into date
with UTC time.
start value: an iCalendar "date with UTC time"
end value: an iCalendar "date with UTC time"
]]>
limit-recurrence-set
urn:ietf:params:xml:ns:caldav
Specifies a time range to limit the set of "overridden
components" returned by the server.
The CALDAV:limit-recurrence-set XML element specifies
that for a given calendaring REPORT request the server
MUST return, in addition to the "master component", only the
"overridden components" that impact a specified time
range. An overridden component impacts a time range if
its current start and end times overlap the time range,
or if the original start and end times - the ones that
would have been used if the instance were not overridden
- overlap the time range.
The "start" attribute specifies the inclusive start of
the time range, and the "end" attribute specifies the
non-inclusive end of the time range. Both attributes are
specified as date with UTC time value. The value of the
"end" attribute MUST be greater than the value of the
"start" attribute.
The server MUST use the same logic as defined for
CALDAV:time-range to determine if the current or
original scheduled time of an "overridden"
recurrence instance intersect the specified time
range.
Overridden components that have a RANGE parameter on their
RECURRENCE-ID property may specify one or more instances
in the recurrence set, and some of those instances may
fall within the specified time range, or may have
originally fallen within the specified time range prior
to being overridden. If that is the case, the overridden
component MUST be included in the results as it has a
direct impact on the interpretation of instances within
the specified time range.
start value: an iCalendar "date with UTC time"
end value: an iCalendar "date with UTC time"
]]>
limit-freebusy-set
urn:ietf:params:xml:ns:caldav
Specifies a time range to limit the set of FREEBUSY
values returned by the server.
The CALDAV:limit-freebusy-set XML element specifies
that for a given calendaring REPORT request the server
MUST only return the FREEBUSY property values of a
VFREEBUSY component that intersect a specified time
range.
The "start" attribute specifies the inclusive start of
the time range, and the "end" attribute specifies the
non-inclusive end of the time range. Both attributes are
specified as "date with UTC time" value. The value of the
"end" attribute MUST be greater than the value of the
"start" attribute.
The server MUST use the same logic as defined for
CALDAV:time-range to determine if a FREEBUSY property
value intersect the specified time range.
start value: an iCalendar "date with UTC time"
end value: an iCalendar "date with UTC time"
]]>
filter
urn:ietf:params:xml:ns:caldav
Specifies a filter to limit the set of calendar
components returned by the server.
The CALDAV:filter XML element specifies the search
filter used to limit the calendar components returned
by a calendaring REPORT request.
]]>
comp-filter
urn:ietf:params:xml:ns:caldav
Specifies search criteria on calendar components.
The CALDAV:comp-filter XML element specifies the
queried calendar component type (e.g., "VEVENT").
A calendar object resource is said to match a
CALDAV:comp-filter if:
A component of the type specified by the "name"
attribute exists, and the CALDAV:comp-filter is empty, or
it contains at least one recurrence instance scheduled to
overlap a given time range if a CALDAV:time-range XML
element is specified, and that any CALDAV:prop-filter and
CALDAV:comp-filter child elements also match.or:
A component of the type specified by the "name"
attribute does not exist, and the CALDAV:is-not-defined
element is specified.
name value: a calendar component name (e.g., "VEVENT")
]]>
prop-filter
urn:ietf:params:xml:ns:caldav
Specifies search criteria on calendar properties.
The CALDAV:prop-filter XML element specifies a
search criteria on a specific calendar property
(e.g., CATEGORIES) in the scope of a given
CALDAV:comp-filter. A calendar component is said
to match a CALDAV:prop-filter if:
A property of the type specified by the "name"
attribute exists, and the CALDAV:prop-filter is empty, or
it matches the CALDAV:time-range XML element or
CALDAV:text-match conditions if specified, and that any
CALDAV:param-filter child elements also match.or:
A property of the type specified by the "name"
attribute does not exist, and the CALDAV:is-not-defined
element is specified.
name value: a calendar property name (e.g., "ATTENDEE")
]]>
param-filter
urn:ietf:params:xml:ns:caldav
Limits the search to specific parameter values.
The CALDAV:param-filter XML element specifies a
search criteria on a specific calendar property
parameter (e.g., PARTSTAT) in the scope of a
given CALDAV:prop-filter. A calendar property
is said to match a CALDAV:param-filter if:
A parameter of the type specified by the "name"
attribute exists, and the CALDAV:param-filter is empty, or
it matches the CALDAV:text-match conditions if specified.or:
A parameter of the type specified by the "name"
attribute does not exist, and the CALDAV:is-not-defined
element is specified.
name value: a property parameter name (e.g., "PARTSTAT")
]]>is-not-defined
urn:ietf:params:xml:ns:caldavSpecifies that a match should occur if
the enclosing component, property or parameter does not exist.
The CALDAV:is-not-defined XML element specifies that
a match occurs if the enclosing component, property or parameter
value specified in a calendaring REPORT request does not
exist in the calendar data being tested.
]]>text-match
urn:ietf:params:xml:ns:caldavSpecifies a substring
match on a property or parameter value.
The CALDAV:text-match XML element specifies text used
for a substring match against the property or parameter
value specified in a calendaring REPORT request.The "caseless" attribute indicates whether the match
is case-sensitive (value set to "no") or case-insensitive
(value set to "yes"). The default value is
server-specified. Support for the "caseless" attribute is
REQUIRED, and implementers of servers are strongly
encouraged to consult "The Unicode Standard" , especially Section 5.18, Subsection
"Caseless Matching", for guidance when implementing their
case-insensitive matching algorithms.. A server MAY
ignore the caseless attribute when applied to enumerated
iCalendar property or parameter values, and default to
caseless matching for those values, since they are
defined as being case-insensitive in iCalendar.The "negate-condition" attribute is used to indicate
that this test returns a match if the text matches, when
the attribute value is set to "no", or return a match if
the text does not match, if the attribute value is set to
"yes". For example, this can be used to match components
with a STATUS property not set to CANCELLED.
PCDATA value: string
]]>
timezone
urn:ietf:params:xml:ns:caldav
Specifies the time zone component to use when determining the
results of a report.
The CALDAV:timezone XML element specifies that for a
given calendaring REPORT request the server MUST rely
on the specified VTIMEZONE component instead of the
CALDAV:calendar-timezone property of the calendar
collection in which the calendar object resource is
contained to resolve "date" values and "date with local
time" values (i.e., floating time) to "date with UTC time"
values. The server will require this information to
determine if a calendar component scheduled with "date"
values or "date with local time" values intersect a
CALDAV:time-range specified in a CALDAV:calendar-query
REPORT.
The iCalendar data embedded within the CALDAV:timezone XML
element MUST follow the standard XML character data encoding rules,
including use of <, >, & etc entity encoding
or the use of a <[!CDATA[ ... ]]> construct. In the later case
the iCalendar data cannot contain the character sequence "]]>"
which is the end delimiter for the CDATA section.
PCDATA value: an iCalendar object with exactly one VTIMEZONE
]]>
time-range
urn:ietf:params:xml:ns:caldav
Specifies a time range to limit the set of calendar
components returned by the server.
The CALDAV:time-range XML element specifies that for a
given calendaring REPORT request the server MUST only
return the calendar object resources that, depending on the
context, have a component or property whose value intersect
a specified time range.
The "start" attribute specifies the inclusive start of the
time range, and the "end" attribute specifies the
non-inclusive end of the time range. Both attributes MUST be
specified as "date with UTC time" value. Time ranges open
at one end can be specified by including only one
attribute, however at least one attribute MUST always be
present in the CALDAV:time-range element. If either the
"start" or "end" attribute is not specified in the
CALDAV:time-range XML element, assume "-infinity" and
"+infinity" as their value respectively. If both "start"
and "end" are present, the value of the "end" attribute
MUST be greater than the value of the "start" attribute.
Time range tests MUST consider every recurrence instance
when testing the time range condition - if any one instance
matches, then the test returns true. Testing recurrence
instances requires the server to infer an effective value
for DTSTART, DTEND, DURATION and DUE properties for an
instance based on the recurrence patterns and any overrides.
A VEVENT component overlaps a given time range if the
condition for the corresponding component state specified in
the table below is satisfied. Note that as specified in
the DTSTART property is REQUIRED in
the VEVENT component. The conditions depend on the presence
of the DTEND and DURATION properties in the VEVENT
component. Furthermore, the value of the DTEND property MUST
be later in time than the value of the DTSTART property. The
duration of a VEVENT component with no DTEND and DURATION
properties is 1 day (+P1D) when the DTSTART is a DATE value,
and 0 seconds when the DTSTART is a DATE-TIME value.
DTSTART) |
+---+---+---+---+-----------------------------------------------+
| N | Y | Y | * | (start < DTSTART+DURATION AND end > DTSTART) |
| | +---+---+-----------------------------------------------+
| | | N | * | (start <= DTSTART AND end > DTSTART) |
+---+---+---+---+-----------------------------------------------+
| N | N | N | Y | (start <= DTSTART AND end > DTSTART) |
+---+---+---+---+-----------------------------------------------+
| N | N | N | N | (start < DTSTART+P1D AND end > DTSTART) |
+---+---+---+---+-----------------------------------------------+
]]>
A VTODO component is said to overlap a given time range if
the condition for the corresponding component state
specified in the table below is satisfied. The conditions
depend on the presence of the DTSTART, DURATION, DUE,
COMPLETED and CREATED properties in the VTODO component.
Note that as specified in the DUE
value MUST be a DATE-TIME value equal to or after the DTSTART
value, if specified.
DTSTART) OR |
| | | | | | (end >= DTSTART+DURATION)) |
+---+---+---+---+---+-----------------------------------------------+
| Y | N | Y | * | * | ((start < DUE) OR (start <= DTSTART)) |
| | | | | | AND |
| | | | | | ((end > DTSTART) OR (end >= DUE)) |
+---+---+---+---+---+-----------------------------------------------+
| Y | N | N | * | * | (start <= DTSTART) AND (end > DTSTART) |
+---+---+---+---+---+-----------------------------------------------+
| N | N | Y | * | * | (start < DUE) AND (end >= DUE) |
+---+---+---+---+---+-----------------------------------------------+
| N | N | N | Y | Y | ((start <= CREATED) OR (start <= COMPLETED))|
| | | | | | AND |
| | | | | | ((end >= CREATED) OR (end >= COMPLETED))|
+---+---+---+---+---+-----------------------------------------------+
| N | N | N | Y | N | (start <= COMPLETED) AND (end >= COMPLETED) |
+---+---+---+---+---+-----------------------------------------------+
| N | N | N | N | Y | (end > CREATED) |
+---+---+---+---+---+-----------------------------------------------+
| N | N | N | N | N | TRUE |
+---+---+---+---+---+-----------------------------------------------+
]]>
A VJOURNAL component overlaps a given time range if the
condition for the corresponding component state specified in
the table below is satisfied. The conditions depend on the
presence of the DTSTART property in the VJOURNAL component
and on whether the DTSTART is a DATE-TIME or DATE value. The
effective "duration" of a VJOURNAL component is 1 day (+P1D)
when the DTSTART is a DATE value, and 0 seconds when the
DTSTART is a DATE-TIME value.
DTSTART) |
+---+---+--------------------------------------------+
| Y | N | (start < DTSTART+P1D) AND (end > DTSTART) |
+---+---+--------------------------------------------+
| N | * | FALSE |
+---+---+--------------------------------------------+
]]>
A VFREEBUSY component overlaps a given time range if the
condition for the corresponding component state specified
in the table below is satisfied. The conditions depend on
the presence in the VFREEBUSY component of the DTSTART and
DTEND properties and any FREEBUSY properties in the absence
of DTSTART and DTEND. Any DURATION property
is ignored as it has a special meaning when used in a
VFREEBUSY component.
When only FREEBUSY properties are used, each period in each
FREEBUSY property is compared against the time range,
irrespective of the type of free busy information (free,
busy, busy-tentative, busy-unavailable) represented by the
property.
DTSTART) |
+---+---+----------------------------------------------+
| N | Y | (start < freebusy-period-end) AND |
| | | (end > freebusy-period-start) |
+---+---+----------------------------------------------+
| N | N | FALSE |
+---+---+----------------------------------------------+
]]>
A VALARM component is said to overlap a given time range if
the following condition holds:
trigger-time)
]]>
A VALARM component can be defined such that it
triggers repeatedly. Such a VALARM component is
said to overlap a given time range if at least
one of its triggers overlaps the time range.
The calendar properties COMPLETED, CREATED, DTEND, DTSTAMP,
DTSTART, DUE and LAST-MODIFIED overlap a given time range if
the following condition holds:
date-time)
]]>
Note that if DTEND is not present in a VEVENT, but DURATION is, then the test should instead operate on the 'effective' DTEND, i.e. DTSTART+DURATION. Similarly, if DUE is not present in a VTODO, but DTSTART and DURATION are, then the test should instead operate on the 'effective' DUE, i.e. DTSTART+DURATION.
The semantic of CALDAV:time-range is not defined
for any other calendar properties.
start value: an iCalendar "date with UTC time"
end value: an iCalendar "date with UTC time"
]]>
calendar-multiget
urn:ietf:params:xml:ns:caldav
CalDAV REPORT used to retrieve specific calendar
object resources.
See .
]]>
free-busy-query
urn:ietf:params:xml:ns:caldav
CalDAV REPORT used to generate a
VFREEBUSY to determine busy time over a specific
time range.
See .
]]>
CalDAV allows internationalized strings to be stored and
retrieved for the description of calendar collections
(see ).
HTTP protocol transactions are sent in the clear over the
network unless protection from snooping is negotiated. This
can be accomplished by use of TLS as defined in
.
In particular, HTTP Basic authentication MUST NOT be used
unless TLS is in effect.
Servers MUST take adequate precautions to ensure malicious
clients cannot consume excessive server resources (CPU, memory,
disk, etc.) through carefully crafted reports. For example, a
client could upload an event with a recurrence rule that
specifies a recurring event occurring every second for the next
100 years which would result in approximately 3 x 10^9
instances! A REPORT that asks for recurrences to be expanded
over that range would likely constitute a denial-of-service
attack on the server.
When creating new resources (including calendar collections), clients
MUST ensure that the resource name (the last path segment of the resource
URI) assigned to the new resource does not
expose any data from within the iCalendar resource itself and information
about the nature of a calendar collection. This is required to ensure that
the presence of a specific iCalendar component or nature of components in
a collection cannot be inferred based on the name of a resource.
Security considerations described in
iCalendar and
iTIP are also applicable to CalDAV.
Beyond these, CalDAV does not raise any security considerations
that are not present in HTTP and
WebDAV , ,
, as discussed in those documents.
This document uses one new URN to identify a new XML namespace.
The URN conforms to a registry mechanism described in
.
Registration request for the CalDAV namespace: URI: urn:ietf:params:xml:ns:caldav Registrant Contact: See the "Author's Address" section of
this document. XML: None. Namespace URIs do not represent an XML
specification.
The authors would like to thank the following individuals
for contributing their ideas and support for writing this
specification: Michael Arick, Mario Bonin, Chris Bryant,
Scott Carr, Mike Douglass, Helge Hess, Dan Mosedale,
Kervin L. Pierre, Julian F. Reschke, Mike Shaver,
Simon Vaillancourt, Wilfredo Sanchez and
Jim Whitehead, Alexey Melnikov, Jeff McCullough,
Brian Moseley, Jari Urpalainen.
The authors would also like to thank the Calendaring and
Scheduling Consortium for advice with this specification,
and for organizing interoperability testing events to help
refine it.
Key words for use in RFCs to Indicate Requirement LevelsHarvard University1350 Mass. Ave.CambridgeMA 02138- +1 617 495 3864sob@harvard.edu
General
keyword
In many standards track documents several words are used to signify
the requirements in the specification. These words are often
capitalized. This document defines these words as they should be
interpreted in IETF documents. Authors who follow these guidelines
should incorporate this phrase near the beginning of their 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
RFC 2119.
Note that the force of these words is modified by the requirement
level of the document in which they are used.
The TLS Protocol Version 1.0Certicomtdierks@certicom.comCerticomcallen@certicom.comThis document specifies Version 1.0 of the Transport Layer Security (TLS) protocol. The TLS protocol provides communications privacy over the Internet. The protocol allows client/server applications to communicate in a way that is designed to prevent eavesdropping, tampering, or message forgery.Internet Calendaring and Scheduling Core Object Specification (iCalendar)Lotus Development Corporation6544 Battleford DriveRaleighNC27613-3502USA+1-919-676-9515+1-919-676-9564Frank_Dawson@Lotus.comhttp://home.earthlink.net/~fdawsonMicrosoft CorporationOne Microsoft WayRedmondWA98052-6399USA+1-425-936-5522+1-425-936-7329deriks@Microsoft.com
Applications
calendaringschedulingPIM
There is a clear need to provide and deploy interoperable calendaring
and scheduling services for the Internet. Current group scheduling
and Personal Information Management (PIM) products are being extended
for use across the Internet, today, in proprietary ways. This memo
has been defined to provide the definition of a common format for
openly exchanging calendaring and scheduling information across the
Internet.
This memo is formatted as a registration for a MIME media type per
. However, the format in this memo is equally applicable
for use outside of a MIME message content type.
The proposed media type value is 'text/calendar'. This string would
label a media type containing calendaring and scheduling information
encoded as text characters formatted in a manner outlined below.
This MIME media type provides a standard content type for capturing
calendar event, to-do and journal entry information. It also can be
used to convey free/busy time information. The content type is
suitable as a MIME message entity that can be transferred over MIME
based email systems, using HTTP or some other Internet transport. In
addition, the content type is useful as an object for interactions
between desktop applications using the operating system clipboard,
drag/drop or file systems capabilities.
This memo is based on the earlier work of the vCalendar specification
for the exchange of personal calendaring and scheduling information.
In order to avoid confusion with this referenced work, this memo is
to be known as the iCalendar specification.
This memo defines the format for specifying iCalendar object methods.
An iCalendar object method is a set of usage constraints for the
iCalendar object. For example, these methods might define scheduling
messages that request an event be scheduled, reply to an event
request, send a cancellation notice for an event, modify or replace
the definition of an event, provide a counter proposal for an
original event request, delegate an event request to another
individual, request free or busy time, reply to a free or busy time
request, or provide similar scheduling messages for a to-do or
journal entry calendar component. The iCalendar Transport-indendent
Interoperability Protocol (iTIP) defined in is one such
scheduling protocol.
iCalendar Transport-Independent Interoperability Protocol (iTIP) Scheduling Events, BusyTime, To-dos and Journal EntriesMicrosoft CorporationOne Microsoft WayRedmondWA98052-6399USA+1-425-936-9277+1-425-936-8019stevesil@Microsoft.comNetscape Communications Corporation501 East Middlefield RoadMountainViewCA94043USA+1-650-937-2378+1-650-937-2103sman@netscape.comLotus Development Corporation6544 Battleford DriveRaleighNC27613-3502USA+1-919-676-9515+1-919-676-9564Frank_Dawson@Lotus.comhttp://home.earthlink.net/~fdawsonOn Technology, Inc.434 Fayetteville St.Mall, Two Hannover SquareSuite 1600RaleighNC27601+1-919-890-4036+1-919-890-4100rhopson@on.com
Applications
calendaringscheduling
This document specifies how calendaring systems use iCalendar objects
to interoperate with other calendar systems. It does so in a general
way so as to allow multiple methods of communication between systems.
Subsequent documents specify interoperable methods of communications
between systems that use this protocol.
The document outlines a model for calendar exchange that defines both
static and dynamic event, to-do, journal and free/busy objects.
Static objects are used to transmit information from one entity to
another without the expectation of continuity or referential
integrity with the original item. Dynamic objects are a superset of
static objects and will gracefully degrade to their static
counterparts for clients that only support static objects.
This document specifies an Internet protocol based on the iCalendar
object specification that provides scheduling interoperability
between different calendar systems. The Internet protocol is called
the "iCalendar Transport-Independent Interoperability Protocol
(iTIP)".
iTIP complements the iCalendar object specification by adding
semantics for group scheduling methods commonly available in current
calendar systems. These scheduling methods permit two or more
calendar systems to perform transactions such as publish, schedule,
reschedule, respond to scheduling requests, negotiation of changes or
cancel iCalendar-based calendar components.
iTIP is defined independent of the particular transport used to
transmit the scheduling information. Companion memos to iTIP provide
bindings of the interoperability protocol to a number of Internet
protocols.
Hypertext Transfer Protocol -- HTTP/1.1Department of Information and Computer ScienceUniversity of California, IrvineIrvineCA92697-3425+1(949)824-1715fielding@ics.uci.eduWorld Wide Web ConsortiumMIT Laboratory for Computer Science, NE43-356545 Technology SquareCambridgeMA02139+1(617)258-8682jg@w3.orgCompaq Computer CorporationWestern Research Laboratory250 University AvenuePalo AltoCA94305mogul@wrl.dec.comWorld Wide Web ConsortiumMIT Laboratory for Computer Science, NE43-356545 Technology SquareCambridgeMA02139+1(617)258-8682frystyk@w3.orgXerox CorporationMIT Laboratory for Computer Science, NE43-3563333 Coyote Hill RoadPalo AltoCA94034masinter@parc.xerox.comMicrosoft Corporation1 Microsoft WayRedmondWA98052paulle@microsoft.comWorld Wide Web ConsortiumMIT Laboratory for Computer Science, NE43-356545 Technology SquareCambridgeMA02139+1(617)258-8682timbl@w3.org
The Hypertext Transfer Protocol (HTTP) is an application-level
protocol for distributed, collaborative, hypermedia information
systems. It is a generic, stateless, protocol which can be used for
many tasks beyond its use for hypertext, such as name servers and
distributed object management systems, through extension of its
request methods, error codes and headers . A feature of HTTP is
the typing and negotiation of data representation, allowing systems
to be built independently of the data being transferred.
HTTP has been in use by the World-Wide Web global information
initiative since 1990. This specification defines the protocol
referred to as "HTTP/1.1", and is an update to RFC 2068 .
HTTP Over TLSThis memo describes how to use Transport Layer Security (TLS) to secure Hypertext Transfer Protocol (HTTP) connections over the Internet. This memo provides information for the Internet community. Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning)Rational Software20 Maguire RoadLexingtonMA02421USgeoffrey.clemm@rational.comIBM3039 CornwallisResearch Triangle ParkNC27709USjamsden@us.ibm.comIBMHursley ParkWinchesterS021 2JNUKtim_ellison@uk.ibm.comMicrosoftOne Microsoft WayRedmondWA90852USckaler@microsoft.comUC Santa Cruz, Dept. of Computer Science1156 High StreetSanta CruzCA95064USejw@cse.ucsc.edu
This document specifies a set of methods, headers, and resource types
that define the WebDAV (Web Distributed Authoring and Versioning)
versioning extensions to the HTTP/1.1 protocol. WebDAV versioning
will minimize the complexity of clients that are capable of
interoperating with a variety of versioning repository managers, to
facilitate widespread deployment of applications capable of utilizing
the WebDAV Versioning services. WebDAV versioning includes automatic
versioning for versioning-unaware clients, version history
management, workspace management, baseline management, activity
management, and URL namespace versioning.
The IETF XML RegistryThis document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas. Web Distributed Authoring and Versioning (WebDAV) Access Control ProtocolIBM20 Maguire RoadLexingtonMA02421geoffrey.clemm@us.ibm.comgreenbytes GmbHSalzmannstrasse 152MuensterNW48159Germanyjulian.reschke@greenbytes.deOracle Corporation500 Oracle ParkwayRedwood ShoresCA94065eric.sedlar@oracle.comU.C. Santa Cruz, Dept. of Computer Science1156 High StreetSanta CruzCA95064ejw@cse.ucsc.edu
This document specifies a set of methods, headers, message bodies,
properties, and reports that define Access Control extensions to the
WebDAV Distributed Authoring Protocol. This protocol permits a client to
read and modify access control lists that instruct a server whether to
allow or deny operations upon a resource (such as HyperText Transfer
Protocol (HTTP) method invocations) by a given principal. A lightweight
representation of principals as Web resources supports integration of a
wide range of user management repositories. Search operations allow
discovery and manipulation of principals using human names.
HTTP Extensions for Distributed Authoring - WebDAVWebDAV consists of a set of methods, headers, and content-types ancillary to HTTP/1.1 for the management of resource properties, creation and management of resource collections, URL namespace manipulation, and resource locking (collision avoidance). RFC2518 was published in February 1999, and this specification makes minor revisions mostly due to interoperability experience.Extensible Markup Language (XML) 1.0 (Third Edition)The Unicode Standard, Version 4.0The Unicode ConsortiumLightweight Directory Access Protocol (v3)Critical Angle Inc.4815 W Braker Lane #502-385AustinTX 78759USA+1 512 372-3160M.Wahl@critical-angle.comNetscape Communications Corp.501 E. Middlefield Rd.MS MV068Mountain ViewCA 94043USA+1 650 937-3419howes@netscape.comIsode LimitedThe DomeThe SquareRichmondTW9 1DTUK+44-181-332-9091S.Kille@isode.com
Applications
LDAPITU directory service protocoldirectorylightweight directory access protocol
This RFC contained boilerplate in this section which has been moved
to the RFC2223-compliant unnumbered section "Status of this Memo."
This document describes a directory access protocol that provides
both read and update access. Update access requires secure
authentication, but this document does not mandate implementation of
any satisfactory authentication mechanisms.
In accordance with RFC 2026, section 4.4.1, this specification is
being approved by IESG as a Proposed Standard despite this
limitation, for the following reasons:
a. to encourage implementation and interoperability testing of
these protocols (with or without update access) before they
are deployed, and
b. to encourage deployment and use of these protocols in read-only
applications. (e.g. applications where LDAPv3 is used as
a query language for directories which are updated by some
secure mechanism other than LDAP), and
c. to avoid delaying the advancement and deployment of other Internet
standards-track protocols which require the ability to query, but
not update, LDAPv3 directory servers.
Readers are hereby warned that until mandatory authentication
mechanisms are standardized, clients and servers written according to
this specification which make use of update functionality are
UNLIKELY TO INTEROPERATE, or MAY INTEROPERATE ONLY IF AUTHENTICATION
IS REDUCED TO AN UNACCEPTABLY WEAK LEVEL.
Implementors are hereby discouraged from deploying LDAPv3 clients or
servers which implement the update functionality, until a Proposed
Standard for mandatory authentication in LDAPv3 has been approved and
published as an RFC.
vCard MIME Directory ProfileLotus Development Corporation6544 Battleford DriveRaleighNC 27613USA+1-919-676-9515frank_dawson@lotus.comNetscape Communications Corp.501 East Middlefield Rd.Mountain ViewCA 94041USA+1.415.937.3419howes@netscape.com
Applications
MIMEaudiocontent-typedirectorymultipurpose internet mail extensions
This memo defines the profile of the MIME Content-Type for
directory information for a white-pages person object, based on a
vCard electronic business card. The profile definition is independent
of any particular directory service or protocol. The profile is
defined for representing and exchanging a variety of information
about an individual (e.g., formatted and structured name and delivery
addresses, email address, multiple telephone numbers, photograph,
logo, audio clips, etc.). The directory information used by this
profile is based on the attributes for the person object defined in
the X.520 and X.521 directory services recommendations. The profile
also provides the method for including a representation of a
white-pages directory entry within the MIME Content-Type defined by
the 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 .
Calendar Attributes for vCard and LDAPXpertSite.ComISOCORLotusWhen scheduling a calendar entity, such as an event, it is a prerequisite that an organizer has the calendar address of each attendee that will be invited to the event. Additionally, access to an attendee's current "busy time" provides an a priori indication of whether the attendee will be free to participate in the event.In order to meet these challenges, a calendar user agent (CUA) needs a mechanism to locate (URI) individual user's calendar and free/busy time.This memo defines three mechanisms for obtaining a URI to a user's calendar and free/busy time. These include:
- Manual transfer of the information;
- Personal data exchange using the vCard format; and
- Directory lookup using the LDAP protocol.Quota and Size Properties for Distributed Authoring and Versioning (DAV) CollectionsNetwork Resonance, Inc.2483 E. Bayshore RoadSuite 212Palo AltoCA94303US+1 650 812-7705briank@networkresonance.comOpen Source Applications Foundation543 Howard Street5th FloorSan FranciscoCA94105US+1 415 946-3040lisa@osafoundation.org
Applications
WWW Distributed Authoring and Versioning (webdav)quota Web Distributed Authoring and Versioning (WebDAV) servers are frequently deployed with quota (size) limitations. This
document discusses the properties and minor behaviors needed for clients to
interoperate with quota (size) implementations on WebDAV repositories.
The following table extends the WebDAV Method Privilege
Table specified in Appendix B of .
METHODPRIVILEGESMKCALENDARDAV:bindREPORTDAV:read or CALDAV:read-free-busy
(on all referenced resources)
This appendix shows the calendar object resources contained in
the calendar collection queried in the examples throughout
this document.
The content of the calendar collection is being shown as
it would be returned by a CALDAV:calendar-query REPORT request
designed to return all the calendar data in the collection:
>> Request <<
]]>>> Response <<http://cal.example.com/bernard/work/abcd1.ics"fffff-abcd1"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001102Z
DTSTART;TZID=US/Eastern:20060102T100000
DURATION:PT1H
SUMMARY:Event #1
Description:Go Steelers!
UID:74855313FA803DA593CD579A@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd2.ics"fffff-abcd2"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060102T120000
DURATION:PT1H
RRULE:FREQ=DAILY;COUNT=5
SUMMARY:Event #2
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20060206T001121Z
DTSTART;TZID=US/Eastern:20060104T140000
DURATION:PT1H
RECURRENCE-ID;TZID=US/Eastern:20060104T120000
SUMMARY:Event #2 bis
UID:00959BC664CA650E933C892C@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd3.ics"fffff-abcd3"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;PARTSTAT=ACCEPTED;ROLE=CHAIR:mailto:cyrus@example.com
ATTENDEE;PARTSTAT=NEEDS-ACTION:mailto:lisa@example.com
DTSTAMP:20060206T001220Z
DTSTART;TZID=US/Eastern:20060104T100000
DURATION:PT1H
LAST-MODIFIED:20060206T001330Z
ORGANIZER:mailto:cyrus@example.com
SEQUENCE:1
STATUS:TENTATIVE
SUMMARY:Event #3
UID:DC6C50A017428C5216A2F1CD@example.com
END:VEVENT
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd4.ics"fffff-abcd4"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
DTSTAMP:20060205T235335Z
DUE;VALUE=DATE:20060104
STATUS:NEEDS-ACTION
SUMMARY:Task #1
UID:DDDEEB7915FA61233B861457@example.com
BEGIN:VALARM
ACTION:AUDIO
TRIGGER;RELATED=START:-PT10M
END:VALARM
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd5.ics"fffff-abcd5"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
DTSTAMP:20060205T235300Z
DUE;VALUE=DATE:20060106
LAST-MODIFIED:20060205T235308Z
SEQUENCE:1
STATUS:NEEDS-ACTION
SUMMARY:Task #2
UID:E10BA47467C5C69BB74E8720@example.com
BEGIN:VALARM
ACTION:AUDIO
TRIGGER;RELATED=START:-PT10M
END:VALARM
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd6.ics"fffff-abcd6"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
COMPLETED:20051223T122322Z
DTSTAMP:20060205T235400Z
DUE;VALUE=DATE:20051225
LAST-MODIFIED:20060205T235308Z
SEQUENCE:1
STATUS:COMPLETED
SUMMARY:Task #3
UID:E10BA47467C5C69BB74E8722@example.com
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd7.ics"fffff-abcd7"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTODO
DTSTAMP:20060205T235600Z
DUE;VALUE=DATE:20060101
LAST-MODIFIED:20060205T235308Z
SEQUENCE:1
STATUS:CANCELLED
SUMMARY:Task #4
UID:E10BA47467C5C69BB74E8725@example.com
END:VTODO
END:VCALENDAR
HTTP/1.1 200 OKhttp://cal.example.com/bernard/work/abcd8.ics"fffff-abcd8"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VFREEBUSY
ORGANIZER;CN="Bernard Desruisseaux":mailto:bernard@example.com
UID:76ef34-54a3d2@example.com
DTSTAMP:20050530T123421Z
DTSTART:20060101T000000Z
DTEND:20060108T000000Z
FREEBUSY:20050531T230000Z/20050601T010000Z
FREEBUSY;FBTYPE=BUSY-TENTATIVE:20060102T100000Z/20060102T120000Z
FREEBUSY:20060103T100000Z/20060103T120000Z
FREEBUSY:20060104T100000Z/20060104T120000Z
FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:20060105T100000Z/20060105T120000Z
FREEBUSY:20060106T100000Z/20060106T120000Z
END:VFREEBUSY
END:VCALENDAR
HTTP/1.1 200 OK
]]>
Changed requirements for ETags on PUT to better reflect the needs
of CalDAV clients wrt synchronization and reflect what other
standards define or do not define.
Changed CALDAV:read-free-busy privilege so that it is also defined
on regular collections.
Added statement that calendar-query Depth defaults to zero if
header is not present. Fixed one multiget example's Depth header.
Fixed reference to WebDAV Quota RFC.
Changed DAV:resource to DAV:href in CALDAV:no-uid-conflict
element.
Added CALDAV:calendar-collection-location-ok pre-condition
for COPY and MOVE.
Added CALDAV:max-resource-size, CALDAV:min-date-time,
CALDAV:max-date-time, CALDAV:max-instances,
CALDAV:max-attendees-per-instance properties and preconditions.
Changed to 2518bis reference.
Now require 2518bis Class 3 behaviour.
Fixed indentation in examples and removed bogus whitespace before
</C:calendar-data> tags.
Fixed </C:calendar-data/> typo.
Added text to <C:calendar-data> element definition as a
reminder about the need to do XML character data encoding on any
iCalendar data within that element.
Major reworking of CALDAV:time-range element description to better
cover all possibilities for each type of component based on which
properties are present.
Added is-not-defined and negate-condition options to
reports and a new example to illustrate use of those.
Fixed descriptions of some calendar collection properties.
Removed section describing preconditions/postconditions as this is
incorporated into 2518bis.
Clarified issue about separate component types in separate resources.
Reworded section on servers being allowed to reject changes to their own private use iCal values.
Clarified overridden component 'current' and 'original' time range overlap.
Added more section references for XML element definitions.
Reworded limit-recurrence-set definition to try and make it clear that mast component is always returned, but only some overridden one are returned.
Clarified dependence on UNICODE reference for caseless matching.
Added new section about support for X- items when storing data.
Added new precondition to allow servers to reject queries on
unsupported X- items, and a new example.
Added new text about always supporting X- in calendar-data.
Created new section for PUT, COPY and MOVE preconditions.
Report examples re-done with full listing of calendar data
in Appendix.
Removed description of using UID, SUMMARY etc as resource name.
Indicate that calendar object resource may contain only
overridden components.
Add security consideration about not expose details in resource
names.
Add constraint that free-busy-query can only be run on a collection.
Add preconditions for calendar-timezone property/elements in
MKCALENDAR, PROPPATCH and calendar-query REPORT.
Fix principal-match example.
Numerous editorial changes.
Removed the CALDAV:is-defined XML element.
Removed section on privilege aggregation.
Renamed the CALDAV:expand-recurrence-set XML element
to CALDAV:expand and clarified the server behavior.
Renamed the CALDAV:calendar-component-restriction-set
XML element to CALDAV:supported-calendar-component-set.
Renamed the CALDAV:calendar-restrictions XML element
to CALDAV:supported-calendar-data.
Renamed some preconditions as "success conditions" instead
of "failure causes". For instance, the precondition
CALDAV:calendar-collection-location-bad has been renamed
to CALDAV:calendar-collection-location-ok.
Reordered some sections.
Clarified the definition of CALDAV:time-range to specify
that a repeating VALARM component is said to intersect a
given time range if at least one of its trigger intersect
the time range.
Clarified that calendar object resources stored in
calendar collections MUST NOT specify the iCalendar
METHOD property.
Clarified that CALDAV:calendar-data XML element is not a
WebDAV property even though it is specified in the DAV:prop
XML element in both calendaring REPORT requests and responses.
Clarified CALDAV:limit-recurrence-set with respect
to the RANGE parameter on the RECURRENCE-ID property.
Changed the CALDAV:free-busy-query XML element to
contain exactly one CALDAV:time-range XML element.
Changed many ELEMENT and ATTLIST declarations to
comply with DTD syntax.
Changed XML element CALDAV:calendar-query to allow
new XML element CALDAV:timezone.
Changed the XML elements CALDAV:time-range, CALDAV:expand
and CALDAV:limit-recurrence-set to only allow DATE-TIME
with UTC time values for the "start" and "end"
attributes.
Changed description of CALDAV:limit-recurrence-set to
specify that re-scheduled "overridden" recurrence
instances whose original scheduled time used to overlap
the time range specified by the "start" and "end"
attribute should always be returned in a REPORT
response.
Changed the description of the value of
CALDAV:calendar-data XML element to specify that the
CR character (US-ASCII decimal 13) MAY be omitted in
the iCalendar object specified in this XML element.
Added specific requirements for entity tags support.
Added more preconditions.
Added further guidelines about finding calendars.
Added XML element CALDAV:limit-freebusy-set to
limit the set of FREEBUSY property values
returned in VFREEBUSY components.
Added property CALDAV:calendar-timezone on calendar
collections.
Added XML element CALDAV:timezone to override the
CALDAV:calendar-timezone property for a given
CALDAV:calendar-query REPORT request.
Added text on the conversion of "floating date" and
"floating time" values to date with UTC time values.
Completed internationalization considerations section.
Completed security considerations section.
Removed statement that said that client SHOULD
always request DAV:getetag in calendar REPORTs.Removed redefiniton of DAV:response.Removed XML elements CALDAV:calendar-data-only.Removed resource type CALDAV:calendar-home.Moved the CALDAV:calendar-data element in the
DAV:prop element in requests, and in the
DAV:propstat element in responses.Further defined the request body of MKCALENDAR to
allow clients to set properties at calendar
collection creation time.Renamed CALDAV:calendar-home-URL to
CALDAV:calendar-home-setClarified the fact that calendar collections
may only contain calendar object resources and
ordinary collections.Clarified that calendar REPORTs should only be
applied to calendar object resources contained
in calendar collections.Changed the CALDAV:calendar-component-restriction-set
and CALDAV:calendar-restriction properties to always
be protected.Changed to use existing postcondition
DAV:needs-privileges instead of a new
CALDAV:insufficient-privilege postcondition.Added example for limit-recurrence-set.Added example for expand-recurrence-set.Moved CALDAV:calendar-address-set in the
calendar-schedule draft and renamed it to
CALDAV:calendar-user-address-set.Added guidelines on attachments and alarms.Various editorial changes.Added properties calendar-restrictions and
calendar-component-restriction-set on calendar
collections.Added properties calendar-home-URL and
calendar-address-set on principal resources.Removed property calendar-URL on principal
resources.Added pre- and postconditions to reports.Added new XML elements calendar-data-only and
limit-recurrent-set.Modified calendar-data XML element to support
the attributes content-type and version.Reorganised sections 3, 4, 5 & 6 into two sections and
re-ordered sub-sections.Added comment about client not setting a duplicate
displayname.Removed three CalDAV OPTIONS requests.Changed "authenticated user" to "user" in various places.Rewrote section on calendar object resource restrictions for
better clarity.Reworded section "Recurrence and the Data Model".Removed timezone collection feature.Removed ability for a server to return the
Location header on a successful PUT request.Clarified restrictions on calendar object resources contained in
calendar collections.Added preconditions on PUT in calendar collections.Added informative "Guidelines" section, with information
on locking and how to find calendar collections.Moved "Sychronization Operations" section in the
"Guidelines" section.Removed a lot of non-normative text.Removed property promotion/demotion requirements.Removed calendar-owner and cal-scale properties.Removed 'ical' prefix/text from element names.Relaxed WebDAV Class 2 (locking) requirement to a MAY.Relaxed MKCALENDAR requirement to a SHOULD.Moved the XML Namespace section in the Introduction.Added CALDAV: prefix to CalDAV XML elements in the text.Added CALDAV:calendar-multiget report.Added CALDAV:free-busy-query report.Added CALDAV:calendar-description property.Changed CALDAV:calendar-query-result element name to
CALDAV:calendar-dataAdded description and examples of handling timezones.Added mandatory "start" and "end" attributes to the
CALDAV:expand-recurrence-set element.Added three CalDAV OPTIONS requests.Grouped XML Element declarations in a separate section.Added a note about the HTTP Location response
header.Added report calendar-query.Removed reports calendar-property-search and
calendar-time-range.Removed section on CalDAV and timezones.Added requirement to return ETag on creation.Revised data model to remove sub-collections from
calendar collection.Added informative references section.Removed dependencies on DASL.Removed Calendar Containers (simplification that
doesn't seem to remove much functionality)Added MKCALENDAR to create calendars and all
sub-collectionsAdded cal-scale property to calendarsBasically still adding major sections of content: Defined new field values to the OPTIONS
"DAV:" response headerAdded new resource
propertiesAdded new principal propertiesAdded new SCHEDULE method and related headersAdded new privileges for schedulingAdded section on privileges for calendaring,
extending WebDAV ACL privilege setDefined what to do with unrecognized properties in
the bodies of iCalendar events, with respect to
property promotion/demotion