Data Model

The CSA interface is an access method to a conceptual back-end store of calendaring information that is maintained by a calendaring service. A common data model is helpful in visualizing the components of the calendaring information maintained by a calendaring service.

Calendar Entities

The data model is based on the concept of a calendar entity. The calendar is represented by a named collection of administrative calendar attributes and calendar entries. A calendar is owned by an individual user. The user could represent a person, a group of people, or a resource.

The calendar attributes are a set of named values that may represent common, implementation-specific, or application-specific administrative characteristics about the calendar. For example, time zone, name, owner, and access rights to the calendar can be specified in individual calendar attributes.

The calendar entries are the primary components of a calendar. The three classes of calendar entries follow:

• Events

• To Dos

• Memos

Calendar entries are represented by a uniquely named collection of entry attributes. The entry attributes are a set of named values that represent common, implementation-specific, or application-specific characteristics of the calendar entry. For example, an event might contain a start and end date and time, a description, and a subtype. A to do might contain the date it was created, the due date, a priority, and a status. A memo might contain the date it was created and a text content or description.

The calendar attributes and entry attributes consist of a name, type, and value tuple. Common attributes defined by the specification can be extended. Implementations can define implementation-specific attributes. In addition, some implementations may provide the capability for applications to define application-specific attributes. The CDE implementation supports application-defined attributes.

Access Rights

The accessibility of a calendar to an individual user can be controlled by the access rights given that user. Access rights are paired with a calendar user. CSA allows a user to be an individual, group, or resource. The CDE implementation only supports individual users. The access rights are maintained in an access list. The access list is a particular calendar attribute. The access rights are individually controlled and can be accumulated to define a range of accessibility of a user to a calendar and its entries. The access rights can also be specified in terms of the following access roles:

• The owner of a calendar

• The organizer of a particular entry within the calendar

• The sponsor of a particular entry within the calendar

The owner role enables the user to do anything to the calendar or calendar entries that the owner of the calendar can do, including deleting the calendar; viewing, inserting, and changing calendar attributes; adding and deleting calendar entries; and viewing, inserting, and changing entry attributes.

The organizer role enables the user to delete the entry or view and change entry attributes of those calendar entries for which the user is specified as the organizer. The organizer defaults to the calendar user who created the entry.

The sponsor role enables the user to delete the entry or view and change entry attributes for those calendar entries for which the user is specified as the sponsor. The sponsor is the calendar user who effectively owns the calendar entry.

In addition to these roles, an access right can be set to limit access to free time searches; view, insert, or change calendar attributes; or view, insert or change entries, depending on whether they are classified as public, confidential, or private. The entry classification acts as a secondary filter on accessibility.