[higgins-dev] Some changes to IdAS proposal

["Sergey Lyakhov" <slyakhov@xxxxxxxxxxxxxx>]

Jim,

I have encountered with some problems during using IdAS as a result there 
are some proposals to change IdAS interfaces.

1. I propose to remove the method getValues() from IProperty interface. 
There are some reasons to do it:

a)    We need to be able to change a value of Attribute (that extends 
IProperty interface), but we can't say exactly which value will be changed 
in case if Attibute has two or more values;
b)    we can't foreknow which value will be returned by getValue() method if 
Attibute has two or more values;
c)    this method (getValues()) has no any sense in case of complex value 
because we unable to set more then one complex value for attribute;


2. I propose to add "Iterable<IAttribute> getAttributes(URI attrID)" method 
to IHasAttributes interface. This method will return a list of attibutes of 
the same type and will be used instead of IProperty.getValues() to store a 
list of values.


3. We need to be able to set/get "null" value for simple attibute. I propose 
to use the following logic (let's assume that we create "uniqueIdentifier" 
attibute):
a) we create individual of  higgins:SimpleAttribute class (it is 
higgins:String in case of uniqueIdentifier) and set it to a Subject as value 
of higgins:uniqueIdentifier property;
b) if value is not null we create and set appropriate literal, otherwise do 
nothing;

Two possible results are mentioned below:

subject has "uniqueIdentifier" attribute with value = "some ID":

<DigitalSubject>
   <higgins:uniqueIdentifier>
     <higgins:String>
       <higgins:string 
rdf:datatype="http://www.w3.org/2001/XMLSchema#string";>some 
ID</higgins:string>
     </higgins:String>
   </higgins:uniqueIdentifier>
</DigitalSubject>

subject has "uniqueIdentifier" attribute with null value:

<DigitalSubject>
   <higgins:uniqueIdentifier>
     <higgins:String/>
   </higgins:uniqueIdentifier>
</DigitalSubject>

Thanks,
Sergey Lyakhov