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From Michael Bouschen <mbo.t...@spree.de>
Subject Re: [VOTE] Issue 139: Add attribute field-type to element field
Date Wed, 28 Dec 2005 21:33:47 GMT
Hi Craig,

> Hi Andy,
> I don't have a problem with using the element-type to be a 
> comma-separated list as a vendor extension, but in general there is no 
> way to map a heterogeneous (Object or interface type) field.

does this apply the metadata attributes field-type, element-type, 
key-type and value-type?

> So I don't think that we should specify the comma-separated list of 
> possible types as a standard technique.
> What do others think about this?

I think support for a field with multiple types in its field-type 
attribute should not be required. But maybe it makes sense to specify 
the syntax as a comma separated list of type names in case a JDO 
implementation does support this feature.

Regards Michael

> Craig
> On Dec 21, 2005, at 12:11 AM, Andy Jefferson wrote:
>> Hi Craig,
>>> This proposal would allow more specific field type to be specified at
>>> deployment time compared to compile time. For example, a field of
>>> type Object could be specified in the jdo metadata as containing only
>>> instances of type SimpleClass.
>> I don't read the proposal as saying that the user should specify the 
>> type(s) 
>> as comma-separated if they want a field declared as Object to store 
>> class A 
>> or class B or class C. What does the user do when they have a field 
>> declared 
>> as Object and want to do this ?
>> -- 
>> Andy
> Craig Russell
> Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
> 408 276-5638 mailto:Craig.Russell@sun.com
> P.S. A good JDO? O, Gasp!

Michael Bouschen		Tech@Spree Engineering GmbH
mailto:mbo.tech@spree.de	http://www.tech.spree.de/
Tel.:++49/30/235 520-33		Buelowstr. 66			
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