[NeXus-tech] propose adding default for nxdl:definition/@extends

[Peterson, Peter]

The point of default is basically to back door a use="required" on 
people without them feeling obliged. So if extends isn't present then 
someone using a validating parser will get NXobject as the value. 
Something similar for primitives would happen as well. The only downside 
to this is if somebody doesn't have a validating parser, or doesn't use 
the schema, then they lose this feature.

P^2

Pete Jemian wrote:
> Turns out  use="required" and default="NXobject" are mutually exclusive.
> With a default, then use="optional" is the rule.
> 
> When we use primitiveType, it is always with use="required" which is 
> what we want.
> 
> Thus, both suggestions will not pass the XSD rules.
> 
> No changes.
> 
> Peterson, Peter F. (pf9) wrote:
>> Only if we can set the default primitive type for fields and attributes to
>> be NX_CHAR.
>>
>> P^2
>>
>>
>> On 11/19/08 7:03 PM, "Pete Jemian" <prjemian at gmail.com> wrote:
>>
>>   
>>> In the "definition" element, can we default the "extends" attribute to
>>> NXobject?
>>>
>>>     <xs:complexType name="definitionType">
>>>         <xs:group ref="nx:groupGroup" minOccurs="0" maxOccurs="unbounded" />
>>>         <xs:attribute name="name" use="required" />
>>>         <xs:attribute name="type" use="required"
>>> type="nx:definitionTypeAttr" />
>>>         <xs:attribute name="extends" use="required" />
>>>     </xs:complexType>
>>>
>>> change to
>>>         <xs:attribute name="extends" use="required" default="NXobject" />
>>>     
>>   
>