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Difference between revisions of "Attribute"

(Definition)
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{{#eclipseproject:technology.higgins|eclipse_custom_style.css}} [[Image:Higgins_logo_76Wx100H.jpg|right]]
==Definition==
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== Version ==
* An Attribute defines a property of an [[Entity]] or a [[Context]].  
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This page describes the concept of [[Attribute]] used in [[Context Data Model 1.0]] and [[Context Data Model 2.0]]
* An Attribute has a URI-valued type
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* An Attribute has one or more values
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* The values of an Attribute may be literal datatypes (defined by a sub-set of XML Schema literal types) or complex (structured) datatypes
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* 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
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== Details ==
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== Definition ==
* A special kind of [[Identity Attribute]] is called a [[Relation]] whose value is a reference to another [[Digital Subject]] in the same or a different [[Context]]
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* Is a property of an [[Entity]] (or [[Context]]).
* Some [[Identity 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}.
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* Has one or more values all of which MUST be unique
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* Has either simple or complex value(s)
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* Simple values:
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** Are literal values (e.g. "green") based on a "base" XML Schema type URI (e.g. string)
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** The allowed value(s) are defined by a [[Data Range]] (URI)
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* Complex values are [[Entity | Entities]]
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* Are identified by an AttributeId.
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** In CDM 2.0 this attribute id is a UDI.
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** In CDM 1.X it is described it is a string or a UDI.
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== Relationship to RDF/OWL ==
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* The values of an attribute are the union of all objects O found in all RDF {subject, predicate, object} triples {S, P, O} such that S is the id of the Entity (or Context) in question and P is the [[AttributeId]]
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== Kinds of Attributes Defined in CDM ==
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* [[Entity Correlation]]
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* [[Context Correlation]]
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* ...others
  
 
==Examples==
 
==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 Attribute]]s (and associated values) in this context:
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The 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 [[Attribute]]s (and associated values) in this [[Context]]:
* email-address = bob@portcontrol.gov
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* email-address = bob@portcontrol.gov <-- in this case the string "email-address" is the [[AttributeId]]
* phone number = {617-555-1234, 617-333-4321}
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* phone number = {617-555-1234, 617-333-4321} <-- multi-valued attribute example
 
* passport information = ...etc.
 
* passport information = ...etc.
 
* fingerprint data = ...etc.
 
* fingerprint data = ...etc.
 
* surname = "Smith"
 
* 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.
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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 Attribute]]s:
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This same Bob Smith might also be represented as an [[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 [[Attribute]]s:
 
* platinumCustomer = True
 
* platinumCustomer = True
 
* preferredColor = "blue"
 
* preferredColor = "blue"
  
== HOWL ==
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==Note==
<pre>
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# An [[Attribute]] cannot have N>1 values if 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".
</pre>
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==In Higgins==
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==See Also==
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[[Category:Context Data Model 1.1]]
* [http://eclipse.org/higgins Higgins Home]
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* [[Concepts]]
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* [[Higgins Data Model]]
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Latest revision as of 19:12, 26 March 2011

{{#eclipseproject:technology.higgins|eclipse_custom_style.css}}
Higgins logo 76Wx100H.jpg

Version

This page describes the concept of Attribute used in Context Data Model 1.0 and Context Data Model 2.0

Definition

  • Is a property of an Entity (or Context).
  • Has one or more values all of which MUST be unique
  • Has either simple or complex value(s)
  • Simple values:
    • Are literal values (e.g. "green") based on a "base" XML Schema type URI (e.g. string)
    • The allowed value(s) are defined by a Data Range (URI)
  • Complex values are Entities
  • Are identified by an AttributeId.
    • In CDM 2.0 this attribute id is a UDI.
    • In CDM 1.X it is described it is a string or a UDI.

Relationship to RDF/OWL

  • The values of an attribute are the union of all objects O found in all RDF {subject, predicate, object} triples {S, P, O} such that S is the id of the Entity (or Context) in question and P is the AttributeId

Kinds of Attributes Defined in CDM

Examples

The 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 Attributes (and associated values) in this Context:

  • email-address = bob@portcontrol.gov <-- in this case the string "email-address" is the AttributeId
  • phone number = {617-555-1234, 617-333-4321} <-- multi-valued attribute example
  • 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 Bob Smith might also be represented as an 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 Attributes:

  • platinumCustomer = True
  • preferredColor = "blue"

Note

  1. An Attribute cannot have N>1 values if 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".

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