ActivityObject specifies a general object use with activities.
Note that property names and descriptions were reused from http://activitystrea.ms/specs/json/1.0/. Although that
document specifies how activities are serialized in JSON the names and concepts can be reused. Additional properties
and behaviors are added where the JSON abstraction is not suitable.
Provides a permanent, universally unique identifier for the object in the form of an absolute IRI [RFC3987].
An object SHOULD contain a single id property. If an object does not contain an id property, consumers MAY use
the value of the url property as a less-reliable, non-unique identifier.
An IRI [RFC3987] identifying a resource providing an HTML representation of the object.
An object MAY contain a url property
Identifies the type of object. An object MAY contain an objectType property whose value is a String that is
non-empty and matches either the "isegment-nz-nc" or the "IRI" production in [RFC3987].
Note that the use of a relative reference other than a simple name is not allowed.
If no objectType property is contained, the object has no specific type.
Natural-language description of the object encoded as a single String containing HTML markup.
Visual elements such as thumbnail images MAY be included. An object MAY contain a content property.
A natural-language, human-readable and plain-text name for the object. HTML markup MUST NOT be included. An
object MAY contain a displayName property. If the object does not specify an objectType property, the object
SHOULD specify a displayName.
Natural-language summarization of the object encoded as a single String containing HTML markup.
Visual elements such as thumbnail images MAY be included. An activity MAY contain a summary property.
Describes the entity that created or authored the object. An object MAY contain a single author property whose
value is an Object of any type. Note that the author field identifies the entity that created the object and
does not necessarily identify the entity that published the object. For instance, it may be the case that an
object created by one person is posted and published to a system by an entirely different entity.
Note that the author object might by dynamically generated based on the user id of the actual author, if present
in the system.
Returns the user id of the author of this activity object or null if this object was not created
by a user present in this system.
The date and time at which the object was published. An object MAY contain a published property.
The date and time at which a previously published object has been modified. An Object MAY contain an updated property.
An array of one or more additional, associated objects, similar to the concept of attached files in an email
message. An object MAY have an attachments property.
Am array of one or more absolute IRI's [RFC3987] identifying objects that duplicate this object's content.
An object SHOULD contain a downstreamDuplicates property when there are known objects, possibly in a different
system, that duplicate the content in this object. This MAY be used as a hint for consumers to use when
resolving duplicates between objects received from different sources.
An array of one or more absolute IRI's [RFC3987] identifying objects that duplicate this object's content.
An object SHOULD contain an upstreamDuplicates property when a publisher is knowingly duplicating with a new ID
the content from another object. This MAY be used as a hint for consumers to use when resolving duplicates
between objects received from different sources.