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Subject: Re:Re:[ebxml-msg]Issue73:http://schemas.xmlsoap.org/soap/envelopenamespace
Rahul: Thanks for your feedback. My comments are inline. -Arvola -----Original Message----- From: Rahul Srivastava <Rahul.Srivastava@Sun.COM> To: ebxml-msg@lists.oasis-open.org <ebxml-msg@lists.oasis-open.org> Date: Tuesday, February 12, 2002 10:51 PM Subject: Re:[ebxml-msg]Issue73:http://schemas.xmlsoap.org/soap/envelopenamespace >Hi, > >After going through the messaging schemas at: >http://www.oasis-open.org/committees/ebxml-msg/schema/ I would like to make a >few comments, in the continuity of Issue73 thread. > >1. The way these schemas are written are not consistent. > a) msg-header-2_0.xsd, envelope.xsd, xmldsig-core-schema.xsd have the >XMLSchema namespace (http://www.w3.org/2001/XMLSchema) as the default namespace, >whereas, xlink.xsd and xml_lang.xsd have the XMLSchema namespace prefixed. > +It would be better if a single convention is followed when >writing the schemas. Either use prefixes or don't. The broad picture should be >uniform and consistent. <arvola> The ebxml-msg TC is responsible for creating and maintaining msg-header-2_0.xsd; whereas envelope.xsd, xmldsig-core-schema.xsd and xlink.xsd have been developed by other groups. Because some parsers have trouble dealing with namespace URIs that do not directly resolve to their corresponding schemas, we have maintained explicit copies of envelope.xsd, xmldsig-core-schema.xsd and xlink.xsd to allow for the use of the xsi:schemaLocation construct to specify the schemas that are to be imported into their corresponding namespaces. We previously maintained our own copy of xml_lang.xsd to allow for the use of the xml:lang attribute. Recently, we determined that we can instead make use of "http://www.w3.org/2001/03/xml.xsd" and we have opted to refer to the latter instead. We have also discovered that the "http://schemas.xmlsoap.org/soap/envelope/" namespace URI has recently been updated to resolve to a SOAP 1.1 schema based on the W3C Recommendation version of XML Schema. Therefore, it is likely that we will make direct use of that, rather than maintaining our own envelope.xsd snapshot. The point I am trying to make is that we don't have any control over these other schemas. We simply import them to allow for their reuse. </arvola> > > b) msg-header-2_0.xsd, xlink.xsd, xml_lang.xsd have elementFormDefault >and attributeFormDefault attributes specified and set to qualified, whereas, >envelope.xsd does not specify these attributes which defaults to unqualified and >xmldsig-core-schema.xsd specifies only elementFormDefault as qualified. > +Here also inconsistency lies in the use of xxFormDefault >attributes. Somewhere it is used and somewhere it is not. Some have set it to >qualified and some have set it to unqualified. Setting attributeFormDefault to >qualified is not a good practice. If set, all the attributes in the instance >document must be prefixed. This looks like much of pain for the community and >will clutter the instance document with too many prefixes. <arvola> Global attributes within a schema are always defined in the target namespace and have to be qualified. Unlike elements which can be implicitly qualified through the use of a default namespace, there is no equivalent default namespace mechanism that is applicable to attributes. To simplify the construction of an ebXML message instance, we have chosen to require that attributes always be qualified, to avoid the need for exact knowledge of whether an attribute defined in the ebMS namespace has to be qualified or not qualified. </arvola> > >2. There is very less use of annotation tags in these schemas. > It would be nice and helpful to many if annotation tags are used to >describe the element tags e.g. TimeToLive, Action, etc.. This will improve the >readability of schema and make it more expressive. It would not be completely >wrong to say annotations are not at all used in these schemas. <arvola> We have avoided the use of the annotation construct because some participants of the UCC sponsored ebMS interoperability study are using parsers that cannot deal with annotations. I agree that the use of annotations can improve readability of the schema. </arvola> > >3. The namespace for msg-header-2_0.xsd, >'http://www.oasis-open.org/committees/ebxml-msg/schema/msg-header-2_0.xsd' ends >in '.xsd'. This may confuse the community in namespace and schemalocation. I >vote against this. <arvola> We have made a conscious decision to make the namespace identical to the schema location, because some parsers have difficulty locating schemas automatically unless the namespace URI resolves to the corresponding schema. We could have incurred more maintenance overhead on the OASIS ebxml-msg web site to ensure that a namespace URI without the .xsd extension resolves to the appropriate schema definition, but we chose to follow the precedence of the OASIS Security Services TC of including the '.xsd' in the namespace URI to simplify maintenance. </arvola> > >I am still looking in these schemas. :-) > >Cheers, >Rahul. > > >---------------------------------------------------------------- >To subscribe or unsubscribe from this elist use the subscription >manager: <http://lists.oasis-open.org/ob/adm.pl>
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