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Difference between revisions of "Attribute"
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| − | The physical person Bob Smith might be represented as an [[ | + | The physical person [[Entity]] Bob Smith might be represented as an [[I-Node]] in the [[Context]] of his employer, the Port Control Authority. This [[I-Node]] might have the following types of [[Attribute]]s (and associated values) in this [[Context]]: |
* email-address = bob@portcontrol.gov | * email-address = bob@portcontrol.gov | ||
* phone number = {617-555-1234, 617-333-4321} | * phone number = {617-555-1234, 617-333-4321} | ||
| Line 25: | Line 25: | ||
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. | 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 | + | This same [[Entity]] Bob Smith might also be represented as a [[I-Node]] in a "customer-to-Clothes-R-Us" [[Context]] (this customer's relationship with the Clothes-R-Us merchant. In this [[Context]] Bob has these [[Attribute]]s: |
* platinumCustomer = True | * platinumCustomer = True | ||
* preferredColor = "blue" | * preferredColor = "blue" | ||
Revision as of 15:21, 3 February 2008
Contents
Introduction
This page describes the Higgins concept of Attribute.
Definition
- Defines a property of an I-Node or a Context.
- Has a URI-valued type that:
- Identifies the Attribute instances with a given I-Node or Context
- Identifies the Attribute's Attribute Model
- Has one or more values all of which MUST be unique
- The types of the values of an Attribute may be:
- XML-Schema-based literal datatypes (a specific sub-set of the XML Schema literal types)
- Sub-types of the XML-Schema-based literal datatypes
- Complex (structured) datatypes
- The set of values of a single Attribute may be any combination of the value types
Examples
The physical person Entity Bob Smith might be represented as an I-Node in the Context of his employer, the Port Control Authority. This I-Node might have the following types of 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 Entity Bob Smith might also be represented as a I-Node in a "customer-to-Clothes-R-Us" Context (this customer's relationship with the Clothes-R-Us merchant. In this Context Bob has these Attributes:
- platinumCustomer = True
- preferredColor = "blue"
HOWL
Open Issues
- At present an attribute cannot have N>1 values where the values are the same. For example a very odd father might name each of his three kids "frank". Thus the father Entity cannot have an attribute "names-of-children" whose values are "frank, frank, frank".
- We need to be able to describe the reality that "real world" context providers must restrict attributes to be "closed"