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https://issues.apache.org/jira/browse/XERCESJ-1496?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12993227#comment-12993227
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Michael Glavassevich commented on XERCESJ-1496:
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I kind of glossed over the examples when I wrote my first comment, but taking a
deeper look at the W3C test, I wonder if the real issue is that the test is
invalid (or doesn't test what it intended). If the author wanted the assertion
to apply to the list as whole I would have expected to see a restriction of the
list type not its item type, for example:
<xs:element name="list">
<xs:simpleType>
<xs:restriction>
<xs:simpleType>
<xs:list itemType="xs:integer"/>
</xs:simpleType>
<xs:assertion test="count($value) eq count(distinct-values($value))" />
</xs:restriction>
</xs:simpleType>
</xs:element>
> adding new feature to JAXP validator for folded simpleType->list assertions
> evaluation
> --------------------------------------------------------------------------------------
>
> Key: XERCESJ-1496
> URL: https://issues.apache.org/jira/browse/XERCESJ-1496
> Project: Xerces2-J
> Issue Type: Improvement
> Components: XML Schema 1.1 Structures
> Affects Versions: 2.11.0
> Reporter: Mukul Gandhi
> Assignee: Mukul Gandhi
> Priority: Minor
>
> Here's a description of the rationale and benefits of this change, and a
> small schema 1.1 validation use case illustrating the proposed changes.
> One of the test cases in W3C XML Schema 1.1 test suite is as follows:
> XML document [1]:
> <list>1 2 3 4 5</list>
> XML Schema 1.1 document [2]:
> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema";>
>
> <xs:element name="list">
> <xs:simpleType>
> <xs:list>
> <xs:simpleType>
> <xs:restriction base="xs:integer">
> <xs:assertion test="count($value) eq
> count(distinct-values($value))" />
> </xs:restriction>
> </xs:simpleType>
> </xs:list>
> </xs:simpleType>
> </xs:element>
>
> </xs:schema>
> The assertion facet in this example would mean,
> "there must be no duplicates in the list"
> Xerces (before this change) didn't support an use case like above. For the
> above example currently Xerces evaluates assertion for each list item
> (therefore Xerces would make 5 calls to an assertion for this example, and
> the XPath 2 context variable $value being different/"list item" in each
> iteration) -- but this would not serve the purpose of this use case.
> I believe we must support this use case. To support this facility I propose a
> change along the following lines:
> We introduce a new feature on JAXP validator with name
> "http://apache.org/xml/features/validation/foldedSTlist-assertion-evaluation";
> whose default value is an boolean 'false' (therefore not setting this feature
> or making it explicitly 'false' would retain the current Xerces behavior).
> Setting this feature to 'true' would cause assertion evaluation as required
> by the above use case.
> The current Xerces implementation to evaluate assertion facet on each list
> item is also beneficial; for example with a schema 1.1 fragment something
> like below:
> <xs:element name="list">
> <xs:simpleType>
> <xs:list>
> <xs:simpleType>
> <xs:restriction base="xs:integer">
> <xs:assertion test="$value mod 2 = 0" />
> </xs:restriction>
> </xs:simpleType>
> </xs:list>
> </xs:simpleType>
> </xs:element>
> (the assertion failure error messages in this example would tell us, that
> what all list items didn't pass the test AND I believe that this run-time
> behavior is also useful)
> To summarize this change:
> 1. Setting the mentioned JAXP feature to 'true' would cause assertion to be
> evaluated only once on the entire list (which would have a type annotation
> xs:anyAtomicType*).
> 2. Not setting this JAXP feature explicitly (since it's default value is
> 'false' within Xerces XML Schema 1.1 validator), or setting explicitly it's
> value to 'false' would retain the current Xerces behavior as has been
> explained above.
> I hope that this enhancement is useful. I'll shortly be committing changes
> for this facility (along with related support to jaxp.SourceValidator
> sample). Any comments about this change would be helpful to us.
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