[NeXus-definitions-tickets] [NeXusDefinitions] #266: implement difference in rules between base classes and application definitions

[NeXus Base Classes and Instrument Definitions]

#266: implement difference in rules between base classes and application
definitions
-------------------------+--------------------------
 Reporter:  Pete Jemian  |       Owner:  Pete Jemian
     Type:  defect       |      Status:  new
 Priority:  major        |   Milestone:
Component:  general      |  Resolution:
 Keywords:  NXDL schema  |
-------------------------+--------------------------

Comment (by Pete Jemian):

 Implementing this rule may be a bit trickier than it first appears.

 What is needed is to have separate declarations of the NXDL rules defining
 a ''minOccurs'' attribute for the different categories of NXDL
 definitions.  In file '''nxdl.xsd''':

 1. Under {{{<xs:complexType name="groupType">}}}

 {{{
 <xs:attribute name="minOccurs" use="optional" default="0"
 type="xs:nonNegativeInteger">
 }}}

 2. Under {{{<xs:complexType name="fieldType">}}}

 {{{
 <xs:attribute name="minOccurs" use="optional" default="0"
 type="nx:nonNegativeUnbounded">
 }}}

 (note: The use of the NXDL type ''nx:nonNegativeUnbounded'' should
 probably be changed to ''xs:nonNegativeInteger'' as it is not likely to
 use {{{minOccurs="unbounded"}}} in an NXDL definition.)

 These are the rules to be implemented for the '''minOccurs''' attributes:

 || **NXDL category** || **default** || **type** ||
 || ''base classes'' || 0 || {{{xs:nonNegativeInteger}}} ||
 || ''application definitions'' || 1 || {{{xs:PositiveInteger}}} ||
 || ''contributed definitions'' || 0 || {{{xs:nonNegativeInteger}}} ||

 The difficulty is to impose the rule on the proper class with the XML
 Schema file.  Apparently, this specific type of feature is a principle
 feature addition of the {{{xml version="1.1"}}} (XML second edition)
 definition.  (http://www.w3.org/TR/xml11/)  XML 1.1 is not very popular
 and many tools will report the declaration  {{{xml version="1.1"}}} as an
 error.  According to http://en.wikipedia.org/wiki/Xml:
   XML 1.1 is not very widely implemented and is recommended for use only
 by those who need its unique features.

 This will take a bit more investigation.

-- 
Ticket URL: <http://trac.nexusformat.org/definitions/ticket/266#comment:1>
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NeXus Base Classes and Instrument Definitions