NEW ISSUE: JMS user property type values not specified

[Simon Holdsworth <simon_holdsworth@uk.ibm.com>]

TARGET: SCA JMS Binding Specification cd04-rev1

DESCRIPTION: 

(I have a sense of deja vu writing this,
I'm sure we discussed this at some point but I cannot find an open issue
related directly to this)

The JMS binding defines several places
where user properties can be specified, either to be used within a message,
or to be used when created resources.
These properties make use of the BindingProperty
type:

   <complexType name="BindingProperty">
      <simpleContent>
         <extension
base="string">
           
<attribute name="name" type="NMTOKEN" use="required"/>
           
<attribute name="type" type="string" use="optional"
default="xs:string"/>
         </extension>
      </simpleContent>
   </complexType>

Given the default value specified for
the "type" attribute it appears that the value space of the type
attribute is some set of XML schema types.  However nowhere in the
JMS spec is the set of values of the "type" attribute defined.

I hit this issue when looking at testcases
BJM_30025_1 and BJM_30025_2, where we currently only test the setting of
a string-type JMS user property, and my desire was to test setting one
of each possible type, but "possible type" is not defined in
the JMS binding specification.

Where the BindingProperty type is used
for defining resources (destinations, connection factories, etc.), then
I am OK with the value space being open-ended, as this is supposed to be
a mechanism for extensibility.  

However, where BindingProperty type
is used for specifying JMS user properties in messages that are sent, there
is a specific limited set of types that can be used.  
Related to this, the pseudo-schema shows
all property elements as having a type attribute of type "NMTOKEN"
but in the schema the type is "string".

PROPOSAL:

We should specify the set of values
of the "type" attribute of the BindingProperty when used to specify
a JMS user property.  The JMS spec defines the following types for
user properties:  boolean,
byte, short, int, long, float, double,
and String. There is a direct
mapping of these to XML schema type names: xs:boolean, xs:byte, xs:short,
xs:int, xs:long, xs:float, xs:double and xs:string.  Although this
seems fairly obvious it is not spelled out in the spec.   Section
3.2 contains the normative statements that define the behaviour of JMS
user properties, so I think that is the best place for this.  Given
that we already have a normative statement which says that the properties
must be set with the name and type specified, I think it is OK to add a
non-normative statement which defines the mapping.  

In terms of specifying the valid values,
I'm unsure of whether those values would include the "xs:" prefix.
 Note that the default value for the type attribute is defined in
the schema as "xs:string" so it would be consistent that the
set of values also starts with "xs:".

Specific changes:

Update the pseudo-schema to replace
all instances of:   <property name=”NMTOKEN” type=”NMTOKEN”?>*
   
with:   <property name=”NMTOKEN”
type=”string”?>*    

Update section 3.2 to add a paragraph
after the initial paragraph (at line 320):

The JMS specification supports the following
user property types: boolean, byte, short, int, long, float, double, and
String.  These are identified via the property/@type attribute using
the following values: "xs:boolean", "xs:byte", "xs:short",
"xs:int", "xs:long", "xs:float", "xs:double"
and "xs:string" respectively.

Possible alternative:

An alternative solution would be to
define a separate type for specifying UserProperties and define the type
attribute as an enumeration allowing schema validation of these values,
but at this point that is a much more significant impact.

Regards, Simon

Simon Holdsworth

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