Re: Requiredness (two issues)

Glen Daniels wrote:

>Hi WSDL'ers:
>Two related things:
>First off, I continue to believe that the "required" flag on properties
>is NOT necessary.  Property values/constraints simply make the specified
>values available to the runtime.  If you think about why you would ever
>want to require setting a particular property, you can achieve the same
>result by simply requiring a component (feature/module/binding) which
>uses that property.
>Any binding or SOAP module which utilizes particular properties will be
>able to pull the values/constraints for those properties out of the
>component model.  Certain specs may have defined default values for
>properties, so if values for those properties are not expressed in the
>WSDL, they would take on the defaults.  If a property is needed by a
>given feature/binding/module and NOT specified in the WSDL, then this
>would be an error, but I don't think that a "required" flag on the
>property value/constraint helps this situation at all.  Understanding a
>particular feature/binding/module implies understanding the property set
>which is required.
>I propose we pull this out of the spec, which would simplify both the
>prose and the model.
I am against pulling this out of the spec.

 From my perspective, requiring a property to be present and having a 
specific value/constraint is a configuration option . A feature may be 
required and can utilize a set of properties, but not necessarily all of 
them. When WSDL specifies a specific configuration with a required 
property, this means that the property must be present and must have the 
value/satisfy the constraint at runtime. For example if my feature uses 
a property, requiring a specific value means that a particular 
configuration is specified by WSDL. Otherwise it will be an error. This 
is very different than requiring the feature to be present. A feature is 
required or not. However, properties may have a range of values. If we 
don't allow requiring a specific value for a property, this will 
minimize the usability of configurations with properties and it will be 
harder to explain.

As a matter of fact, requiredness covers a range of problems that 
compositions with properties were intending to address ("all"). As 
composition operators are not available at present in WSDL, I don't want 
to remove the requiredness of properties as it will hinder the usability 
of properties.

Using David Orchard's rule of of spec development, (sorry for quoting 
you David ;-)) it may be easier to remove it after LC after we give it 
more thought. ;-)


Umit Yalcinalp                                  
Consulting Member of Technical Staff
Phone: +1 650 607 6154                          

Received on Monday, 26 July 2004 19:32:16 UTC