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Difference between revisions of "Attribute"
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== Details == | == Details == | ||
| + | * Even if all values are literals, they may differ in specific literal datatype (e.g. strings and integers may be intermixed) | ||
* A special kind of [[Attribute]] is called a [[Relation]] whose value is a reference to another [[Digital Subject]] in the same or a different [[Context]] | * A special kind of [[Attribute]] is called a [[Relation]] whose value is a reference to another [[Digital Subject]] in the same or a different [[Context]] | ||
* Some [[Attribute]]s are defined by the containing [[Context]]'s schema to allow multiple '''unique''' values. For example the attribute preferredBreakfast might have the values {spam, eggs}, but it could not have the values {spam, spam, spam, eggs, spam}. | * Some [[Attribute]]s are defined by the containing [[Context]]'s schema to allow multiple '''unique''' values. For example the attribute preferredBreakfast might have the values {spam, eggs}, but it could not have the values {spam, spam, spam, eggs, spam}. | ||
Revision as of 16:21, 31 January 2008
Definition
- An Attribute defines a property of an Entity or a Context.
- An Attributehas a URI-valued type
- An Attributehas one or more values
- The values of an Attribute may be literal datatypes (defined by a sub-set of XML Schema literal types) or complex (structured) datatypes
- The set of values of a single Attribute may contain values that are simple, that are complex, or that are a combination of the two
Details
- Even if all values are literals, they may differ in specific literal datatype (e.g. strings and integers may be intermixed)
- A special kind of Attribute is called a Relation whose value is a reference to another Digital Subject in the same or a different Context
- Some Attributes are defined by the containing Context's schema to allow multiple unique values. For example the attribute preferredBreakfast might have the values {spam, eggs}, but it could not have the values {spam, spam, spam, eggs, spam}.
Examples
The physical person Bob Smith might be represented as an Entity in the Context of his employer, the Port Control Authority. This Entity might have the following types of Identity Attributes (and associated values) in this context:
- email-address = bob@portcontrol.gov
- phone number = {617-555-1234, 617-333-4321}
- passport information = ...etc.
- fingerprint data = ...etc.
- surname = "Smith"
The surname Attribute in the example above might have a type of http://openschemas.org/2006/person/surname. The schema associated with the containing Context provides metadata about this URI.
This same physical person Bob Smith might also be represented as a Entity in a "customer-to-Clothes-R-Us" Context (this customer's relationship with the Clothes-R-Us merchant. In this Context Bob has these Identity Attributes:
- platinumCustomer = True
- preferredColor = "blue"