issue 6403: ws-enum policy proposal

Following the pattern being proposed for WS-Eventing's policy,
define a new section of WS-Enum that has the following:

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WS-Policy Framework and WS-Policy Attachment [WS-PolicyAttachment] 
collectively define a framework, model and grammar for expressing 
the requirements, and general characteristics of entities in an XML 
Web services-based system. To enable a Data Source to describe its
requirements, this specification defines a single policy assertion
that leverages the WS-Policy framework.  This assertion has Endpoint
Policy Subject.

The normative outline of this assertion is:

<wsenp:WSEnumeration [wsp:Optional="true"]? ...>
  <wsp:Policy>
    <x:FilterDialect xmlns:x="xs:anyURI" wsp:Optional="true"/> *
    ...
  </wsp:Policy>
</wsenp:WSEnumeration>

/wsenp:WSEnumeration
  A policy assertion that specifies that WS-Enumeration protocol 
  MUST be used when communicating with this endpoint. This assertion 
  has Endpoint Policy Subject.

/wsenp:WSEnumeration/wsp:Optional
  Per WS-Policy, this is compact notation for two policy alternatives,
  one with and one without the assertion. The intuition is that the 
  behavior indicated by the assertion is optional, or in this case, 
  that WS-Enumeration MAY be used.

/wsenp:WSEnumeration/wsp:Policy
  This required element allows for the inclusion of nested policy 
  assertions.

/wsenp:WSEnumeration/wsp:Policy/x:FilterDialect
  When present, this assertion defines the requirement that the 
  consumer, if it chooses to include a filter in the wsen:Enumerate 
  request, MUST use the filter dialect associated with the namespace 
  URI of this element. Note: the namespace of this element is 
  application defined, but the Local Name MUST be  "FilterDialect".

/wsenp:WSEnumeration/wsp:Policy/x:FilterDialect@wsp:Optional
  This attribute specifies that the assertion is optional per 
  WS-Policy. This attribute MUST be present since the inclusion of 
  a Filter dialect in a Enumerate request is optional.

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Its not clear to me which other features of WS-Enum are optional
(for example, Renew) and should therefore have a policy assertion
associated with it.  But we can add more to the above as we
decide if they are optional.

Also, once we agree on the format of the policy assertion we can
then define the exact policy assertions for the pre-defined
filter dialects.

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
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