Tony, I think everyone’s on board that
an EntityId represents a reference to exactly one Entity in a context. Now its
about cardinality, immutability, and type. Regarding the first two, the current
proposal is that if cardinality is 0..n, the IEntity.getEntityIds() method will return all of them (whether exposed as attributes or
not), and the proposed IEntity.getCanonicalEntityId() method will return only the single EntityId specified in that
context to be: a) canonical, b) immutable. If the context does not support
either canonical immutable IDs, the IEntity.getCanonicalEntityId() method will return an error.
If there’s agreement on that, then
it’s just down to the types returned by those methods and accepted by IContext.getEntity().
=Drummond
From:
higgins-dev-bounces@xxxxxxxxxxx [mailto:higgins-dev-bounces@xxxxxxxxxxx] On Behalf Of Anthony Nadalin
Sent: Thursday, September 18, 2008
10:34 AM
To: Higgins (Trust Framework)
Project developer discussions
Cc: Higgins (Trust Framework)
Project developer discussions; higgins-dev-bounces@xxxxxxxxxxx
Subject: Re: Strawman for 0..n
entity ids [WAS: [higgins-dev] My position onEntityId]
Depends, no one is stating what an EntityID
represents, my view is it resolves to the Entity within a context
Anthony Nadalin | Work 512.838.0085 | Cell 512.289.4122
"Markus
Sabadello" ---09/18/2008 12:30:56 PM---After the call, I had this idea:
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From:
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"Markus
Sabadello" <msabadello@xxxxxxxxxxxxx>
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|
To:
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"Higgins
(Trust Framework) Project developer discussions"
<higgins-dev@xxxxxxxxxxx>
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|
Date:
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09/18/2008 12:30 PM
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Subject:
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Re: Strawman for
0..n entity ids [WAS: [higgins-dev] My position on EntityId]
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After the call, I had this idea:
1. Let's say IEntity.getEntityIds() returns an array of Objects (in Java:
Object[]). These Objects can either be Strings or IAttributeValues. If the
EntityId is not exposed as an attribute, it's just a String. If it is exposed
as an attribute, then it's an IAttributeValue.
2. IEntity.getCanonicalEntityId() returns a single Object. As before, if the
canonical EntityId is not exposed as an attribute, then the Object is a String.
Otherwise it's an IAttributeValue.
3. IContext.getEntity() has two overloaded versions. One that takes a String,
and one that takes an IAttributeValue.
So in total:
public Object[] IEntityId.getEntityIds(); // Objects can either be String or
IAttributeValue
public Object IEntity.getCanonicalEntityId(); // Object can either be String or
IAttributeValue
public IEntity IContext.getEntity(String);
public IEntity IContext.getEntity(IAttributeValue);
You don't invent something new for typing such as key-value pairs. You simply
use the existing IAttributeValue interface. IAttributeValue already includes
the type. And it can be complex, so you can do multi-part keys too.
All the IAttributeValue instances returned by IEntityId.getEntityIds() are
guaranteed to also show up somewhere on the IEntity in an IAttribute that is a
sub-attribute of higgins:synonym.
Would that work?
Markus
