Internet-Draft JMAP Tasks October 2021
Baum & Happel Expires 23 April 2022 [Page]
Workgroup:
JMAP
Internet-Draft:
draft-ietf-jmap-tasks-01
Published:
Intended Status:
Standards Track
Expires:
Authors:
J.M. Baum, Ed.
audriga
H.J. Happel, Ed.
audriga

JMAP for Tasks

Abstract

This document specifies a data model for synchronizing task data with a server using JMAP.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 23 April 2022.

Table of Contents

1. Introduction

JMAP ([RFC8620] - JSON Meta Application Protocol) is a generic protocol for synchronizing data, such as mail, calendars or contacts, between a client and a server. It is optimized for mobile and web environments, and aims to provide a consistent interface to different data types.

JMAP for Calendars ([I-D.ietf-jmap-calendars]) defines a data model for synchronizing calendar data between a client and a server using JMAP. The data model is designed to allow a server to provide consistent access to the same data via CalDAV [RFC4791] as well as JMAP.

While CalDAV defines access to tasks, JMAP for Calendars does not. This specification fills this gap and defines a data model for synchronizing task data between a client and a server using JMAP. It is built upon JMAP for Calendars and reuses most of its definitions. For better readability this document only outlines differences between this specification and JMAP for Calendars. If not stated otherwise, the same specifics that apply to Calendar, CalendarEvent and CalendarEventNotification objects as defined in the aforemetioned specification also apply to similar data types introduced in this specification.

1.1. Notational Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

Type signatures, examples, and property descriptions in this document follow the conventions established in Section 1.1 of [RFC8620]. Data types defined in the core specification are also used in this document.

1.2. Terminology

The same terminology is used in this document as in the core JMAP specification, see [RFC8620], Section 1.6.

The terms ParticipantIdentity, TaskList, Task and TaskNotification are used to refer to the data types defined in this document and instances of those data types.

1.3. Data Model Overview

Similar to JMAP for Calendar, an Account (see [RFC8620], Section 1.6.2) contains zero or more TaskList objects, which is a named collection of Tasks belonging to a Principal (see [I-D.ietf-jmap-sharing] Section XXX). Task lists can also provide defaults, such as alerts and a color to apply to tasks in the calendar. Clients commonly let users toggle visibility of tasks belonging to a particular task list on/off. Servers may allow a task to belong to multiple TaskLists within an account.

A Task is a representation of a single task or recurring series of Tasks in JSTask [I-D.ietf-calext-jscalendar] format. Recurrence rules and alerts as defined in JMAP for Calendars (see [I-D.ietf-jmap-calendars] Section XXX) apply.

Just like the CalendarEventNotification objects (see [I-D.ietf-jmap-calendars] Section XXX), TaskNotification objects keep track of the history of changes made to a task by other users. Similarly, the ShareNotification type (see [I-D.ietf-jmap-sharing] Section XXX) notifies the user when their access to another user's task list is granted or revoked.

1.4. Addition to the Capabilities Object

The capabilities object is returned as part of the JMAP Session object; see [RFC8620], Section 2. This document defines one additional capability URI.

1.4.1. urn:ietf:params:jmap:tasks

This represents support for the TaskList, Task and TaskNotification data types and associated API methods. The value of this property in the JMAP Session capabilities property is an empty object.

The value of this property in an account's accountCapabilities property is an object that MUST contain the following information on server capabilities and permissions for that account:

  • shareesActAs: String This MUST be one of:

    • self - sharees act as themselves when using tasks in this account.
    • secretary- sharees act as the principal to which this account belongs.
  • minDateTime: LocalDate The earliest date-time the server is willing to accept for any date stored in a Task.

  • maxDateTime: LocalDate The latest date-time the server is willing to accept for any date stored in a Task.

  • maxExpandedQueryDuration: Duration The maximum duration the user may query over when asking the server to expand recurrences.

  • maxAssigneesPerTask: Number|null The maximum number of assignees a single task may have, or null for no limit.

  • mayCreateTaskList: Boolean If true, the user may create a task list in this account.

2. Principals

For systems that also support JMAP Sharing [I-D.ietf-jmap-sharing], the tasks capability is used to indicate that this principal may be used with tasks.

2.1. Principal Capability urn:ietf:params:jmap:tasks

A "urn:ietf:params:jmap:tasks" property is added to the Principal "capabilities" object, the value of which is an object with the following properties:

  • accountId: Id|null Id of Account with the urn:ietf:params:jmap:tasks capability that contains the task data for this principal, or null if none (e.g. the Principal is a group just used for permissions management), or the user does not have access to any data in the account.
  • account: Account|null The JMAP Account object corresponding to the accountId, null if none.
  • sendTo: String[String]|null If this principal may be added as a participant to a task, this is the map of methods for adding it, in the same format as Participant#sendTo in JSTask (see [I-D.ietf-calext-jscalendar], Section 4.4.5).

3. Assignee Identities

An AssigneeIdentity stores information about a URI that represents the user within that account in a task's assignees. It has the following properties:

An assignee in an task corresponds to an AssigneeIdentity if any of the method/uri pairs in the sendTo property of the participant are identical to a method/uri pair in the sendTo property of the identity.

The following JMAP methods are supported.

3.1. AssigneeIdentity/get

This is a standard "/get" method as described in [RFC8620], Section 5.1. The ids argument may be null to fetch all at once.

3.2. AssigneeIdentity/changes

This is a standard "/changes" method as described in [RFC8620], Section 5.2.

3.3. AssigneeIdentity/set

This is a standard "/set" method as described in [RFC8620], Section 5.3. The server MAY restrict the uri values the user may claim, for example only allowing mailto: URIs with email addresses that belong to the user. A standard forbidden error is returned to reject non-permissible changes.

4. TaskLists

A TaskList is a named collection of tasks. All tasks are associated with exactly one TaskList.

A TaskList object has the following properties:

A TaskRights object has the following properties:

The user is an owner for a task if the Task object has an "assignee" property, and one of the Participant objects both:

  1. Has the "chair" role.
  2. Corresponds to one of the user's AssigneeIdentity objects in the account.

A task has no owner if its assignee property is null or omitted.

4.1. TaskList/get

This is a standard "/get" method as described in [RFC8620], Section 5.1. The ids argument may be null to fetch all at once.

4.2. TaskList/changes

This is a standard "/changes" method as described in [RFC8620], Section 5.2.

4.3. TaskList/set

This is the "Calendar/set" method as described in [I-D.ietf-jmap-calendars], Section XXX.

  • onDestroyRemoveTasks: Boolean (default: false)

If false, any attempt to destroy a TaskList that still has Tasks in it will be rejected with a TaskListHasTask SetError. If true, any Tasks that were in the TaskList will be removed from it and they will be destroyed.

The "role" and "shareWith" properties may only be set by users that have the mayAdmin right. The value is shared across all users, although users without the mayAdmin right cannot see the value.

When modifying the shareWith property, the user cannot give a right to a principal if the principal did not already have that right and the user making the change also does not have that right. Any attempt to do so must be rejected with a forbidden SetError.

Users can subscribe or unsubscribe to a task list by setting the "isSubscribed" property. The server MAY forbid users from subscribing to certain task lists even though they have permission to see them, rejecting the update with a forbidden SetError.

The "timeZone", "defaultAlertsWithoutTime" and "defaultAlertsWithTime" properties are stored per-user if the task list account's "shareesActAs" capability is "self", and may be set by any user who is subscribed to the task list. Otherwise, these properties are shared, and may only be set by users that have the mayAdmin right.

The following properties may be set by anyone who is subscribed to the task list and are all stored per-user:

These properties are initially inherited from the owner's copy of the task list, but if set by a sharee that user gets their own copy of the property; it does not change for any other principals. If the value of the property in the owner's task list changes after this, it does not overwrite the sharee's value.

The following extra SetError types are defined:

For "destroy":

  • taskListHasTask: The Task List has at least one Task assigned to it, and the "onDestroyRemoveTasks" argument was false.

5. Tasks

A Task object contains information about a task, or recurring series of tasks. It is a JSTask object, as defined in [I-D.ietf-calext-jscalendar], with the following additional properties:

5.1. Additional JSCalendar properties

This document defines four new JSCalendar properties.

5.1.1. mayInviteSelf

Type: Boolean (default: false)

If true, any user that has access to the task may add themselves to it as a participant with the "attendee" role. This property MUST NOT be altered in the recurrenceOverrides; it may only be set on the master object.

5.1.2. mayInviteOthers

Type: Boolean (default: false)

If true, any current participant with the "attendee" role may add new participants with the "attendee" role to the task. This property MUST NOT be altered in the recurrenceOverrides; it may only be set on the master object.

5.1.3. hideAttendees

Type: Boolean (default: false)

If true, only the owners of the task may see the full set of participants. Other sharees of the task may only see the owners and themselves. This property MUST NOT be altered in the recurrenceOverrides; it may only be set on the master object.

5.1.4. relatedTo

Type: Id[String]|null (default: null)

A map of task ids to relations. Relation SHOULD be one of: - blockedBy: Blocked by task with id. - clonedBy: Task with id was cloned from this issue. - duplicatedBy: Task with id is a duplicate of this issue. - causedBy: Task with id was the cause for this task. - relatesTo: Task with id is related. - childOf: Task with id is parent.

5.2. Properties similar in JMAP for Calendar

Attachments, per-user properties, recurrences and updates to recurrences are described in [I-D.ietf-jmap-calendars], Section XXX.

5.3. Task/get

This is the "CalendarEvent/get" method as described in [I-D.ietf-jmap-calendars], Section XXX.

TODO redefine this here. Similar to "TaskList/get" we only need to replace a few definitions. For example, replace reduceParticipants with reduceAssignees. Copy+Paste most of the stuff.

5.4. Task/changes

This is a standard "/changes" method as described in [RFC8620], Section 5.2.

5.5. Task/set

This is the "CalendarEvent/set" method as described in [I-D.ietf-jmap-calendars], Section XXX.

TODO copy+paste most stuff from "CalendarEvent/set". It should be fine to just reference patching.

5.6. Task/copy

This is a standard "/copy" method as described in [RFC8620], Section 5.4.

5.7. Task/query

This is the "CalendarEvent/query" method as described in [I-D.ietf-jmap-calendars], Section XXX.

TODO copy+paste most stuff from "CalendarEvent/query". Mainly filtering should be different.

5.8. Task/queryChanges

This is a standard "/queryChanges" method as described in [RFC8620], Section 5.6.

6. Task Notifications

The TaskNotification data type records changes made by external entities to tasks in task lists the user is subscribed to. Notifications are stored in the same Account as the Task that was changed.

This is the same specification as the CalendarEventNotification object from [I-D.ietf-jmap-calendars], Section XXX. Only the object properties differ slightly and are therefore fully described in this document.

6.1. Object Properties

The TaskNotification object has the following properties:

  • id: String The id of the TaskNotification.
  • created: UTCDate The time this notification was created.
  • changedBy: Person Who made the change.

    • name: String The name of the person who made the change.
    • email: String The email of the person who made the change, or null if no email is available.
    • principalId: String|null The id of the principal corresponding to the person who made the change, if any. This will be null if the change was due to receving an iTIP message.
  • comment: String|null Comment sent along with the change by the user that made it. (e.g. COMMENT property in an iTIP message).
  • type: String This MUST be one of

    • created
    • updated
    • destroyed
  • TaskId: String The id of the Task that this notification is about.
  • isDraft: Boolean (created/updated only) Is this task a draft?
  • task: JSTask The data before the change (if updated or destroyed), or the data after creation (if created).
  • taskPatch: PatchObject (updated only) A patch encoding the change between the data in the task property, and the data after the update.

To reduce data, if the change only affects a single instance of a recurring task, the server MAY set the task and taskPatch properties for the instance; the taskId MUST still be for the master task.

6.2. TaskNotification/get

This is a standard "/get" method as described in [RFC8620], Section 5.1.

6.3. TaskNotification/changes

This is a standard "/changes" method as described in [RFC8620], Section 5.2.

6.4. TaskNotification/set

This is a standard "/changes" method as described in [RFC8620], Section 5.3.

Only destroy is supported; any attempt to create/update MUST be rejected with a forbidden SetError.

6.5. TaskNotification/query

This is a standard "/query" method as described in [RFC8620], Section 5.5.

6.5.1. Filtering

A FilterCondition object has the following properties:

  • after: UTCDate|null The creation date must be on or after this date to match the condition.
  • before: UTCDate|null The creation date must be before this date to match the condition.
  • type: String The type property must be the same to match the condition.
  • taskIds: Id[]|null A list of task ids. The taskId property of the notification must be in this list to match the condition.

6.5.2. Sorting

The "created" property MUST be supported for sorting.

6.6. TaskNotification/queryChanges

This is a standard "/queryChanges" method as described in [RFC8620], Section 5.6.

7. Security Considerations

All security considerations of JMAP for Calendars [I-D.ietf-jmap-calendars] apply to this specification.

8. IANA Considerations

8.1. JMAP Capability Registration for "tasks"

IANA will register the "tasks" JMAP Capability as follows:

Capability Name: urn:ietf:params:jmap:tasks

Specification document: this document

Intended use: common

Change Controller: IETF

Security and privacy considerations: this document, Section XXX

8.2. JSCalendar Property Registrations

All IANA registrations for JSTask are described in JMAP for Calendars [I-D.ietf-jmap-calendars].

9. Normative References

[I-D.ietf-calext-jscalendar]
Jenkins, N. and R. Stepanek, "JSCalendar: A JSON Representation of Calendar Data", Work in Progress, Internet-Draft, draft-ietf-calext-jscalendar-32, , <https://datatracker.ietf.org/doc/html/draft-ietf-calext-jscalendar-32>.
[I-D.ietf-jmap-calendars]
Jenkins, N. and M. Douglass, "JMAP for Calendars", Work in Progress, Internet-Draft, draft-ietf-jmap-calendars-06, , <https://datatracker.ietf.org/doc/html/draft-ietf-jmap-calendars-06>.
[I-D.ietf-jmap-sharing]
Jenkins, N., "JMAP Sharing", Work in Progress, Internet-Draft, draft-ietf-jmap-sharing-00, , <https://datatracker.ietf.org/doc/html/draft-ietf-jmap-sharing-00>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[RFC8620]
Jenkins, N. and C. Newman, "The JSON Meta Application Protocol (JMAP)", RFC 8620, DOI 10.17487/RFC8620, , <https://www.rfc-editor.org/info/rfc8620>.

10. Informative References

[RFC4791]
Daboo, C., Desruisseaux, B., and L. Dusseault, "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, DOI 10.17487/RFC4791, , <https://www.rfc-editor.org/info/rfc4791>.

Authors' Addresses

Joris Baum (editor)
audriga
Durlacher Allee 47
76131 Karlsruhe
Germany
Hans-Joerg (editor)
audriga
Durlacher Allee 47
76131 Karlsruhe
Germany