If you allow "xsd:any" or "string-or-number" or anything else where there you can specify a choice of data types for the attribute data type, then the data type for any given attribute value instance must be specified in the IdAS API. In such a case, the context provider cannot assume that the schema will tell it what the data type is for a particular value instance - as it could be one of several possibilities.|
>>> "Drummond Reed" <drummond.reed@xxxxxxxxxxxx> 1/7/2008 11:02 PM >>>
That's a reasonable use case, however I would argue that in that case the data type is xsd:any, and thus it still fits the rule that all values are of the same type.
The same could be applied to Daniel's telephone number example: the datatype is really "string-or-number".
From: higgins-dev-bounces@xxxxxxxxxxx [mailto:higgins-dev-bounces@xxxxxxxxxxx] On Behalf Of Jim Sermersheim
Sent: Monday, January 07, 2008 8:25 PM
To: Higgins (Trust Framework) Project developer discussions
Subject: Re: Fwd: [higgins-dev] Higgins data model for attribute values
Thanks for the feedback, all.
This is as I expected. I have heard some use cases for allowing an attribute's values to be different data types -- similar to specifying that an element in an xml schema be of xsd:any type. One case I remember that Daniel brought up was like: What if I have an attribute which represents a telephone number and I want to allow different data types (strings as well as numbers) to be stored?
Daniel or others can probably provide more compelling arguments.
>>> "Markus Sabadello" <msabadello@xxxxxxxxxxxxx> 01/07/08 1:38 PM >>>
From: Paul Trevithick <paul@xxxxxxxxxxxxx >
Date: January 7, 2008 3:13:12 PM EST
To: "Higgins (Trust Framework) Project developer discussions" <higgins-dev@xxxxxxxxxxx >
Cc: "Higgins (Trust Framework) Project developer discussions" <higgins-dev@xxxxxxxxxxx>
Subject: Re: [higgins-dev] Higgins data model for attribute values
Wrt the higgins data model all values must be of the same type.
As for higgins.owl, I'm working on a rev that will address this and other related issues
Good question, Jim. My assumption would have been that if an Attribute allows multiple values, they all would be of the same data type. Is there a use case for an Attribute having multiple values with different data types?
Before addressing bug #190594, I need to know more about what the Higgins data model allows in an attribute's instance data.
In IdAS, my understanding is that a Digital Subject may have 0..1 occurrence of a particular Attribute, and that an Attribute may have 1..N occurrences of a particular type of Value.
It's my understanding that each of an Attribute's values must be of the same data type, but that restriction isn't obvious to me in the Higgins OWL, and in fact, the opposite is reflected in the IdAS APIs. In IdAS, one can state the data type of each value they add to an attribute.
So, we need to agree on the Higgins data model regarding the types of attribute values. Should the Higgins data model dictate that they all be of the same type, or should it allow their types to be mixed?