Table of Contents
Element context(s)
rule
This attribute is optional and selects items matched by a rule context for further evaluation.
Clause 5.5.21 (
visit-eachattribute)The
visit-eachattribute contains an expression which selects a sequence of items for further evaluation.The expression is evaluated against each item resulting from evaluation of the rule's context expression. If this sequence is non-empty, it becomes the context against which assertions are evaluated, in place of the rule's context. If it is empty, the rule is still considered to have fired.
element rule {
attribute flag { flagValue }?,
rich,
linkable,
(foreign
& inclusion*
& ((attribute context { pathValue },
attribute visit-each { pathValue }?,
attribute id { xsd:ID }?,
attribute abstract { "false" }?,
title?,
let*,
(assert | report | extends | p)+)))
}Example 10. visit-each attribute
Validating this document:
<foo>foo bar blort foo bar</foo>
against a schema containing this rule:
<sch:rule context='foo' visit-each='fn:analyze-string(., "foo")/fn:match'> <sch:report test='.'><sch:name/> at index <sch:value-of select='string-length(string-join(preceding-sibling::fn:*))+1'/></sch:report> </sch:rule>
produces SVRL output containing:
<svrl:fired-rule context="/foo" visit-each="analyze-string(., "foo")/fn:match"/> <successful-report xmlns="http://purl.oclc.org/dsdl/svrl" location="Q{http://www.w3.org/2005/xpath-functions}root()/Q{http://www.w3.org/2005/xpath-functions}match[1]" test="."> <svrl:text>foo at index 1</svrl:text> </successful-report> <successful-report xmlns="http://purl.oclc.org/dsdl/svrl" location="Q{http://www.w3.org/2005/xpath-functions}root()/Q{http://www.w3.org/2005/xpath-functions}match[2]" test="."> <svrl:text>foo at index 15</svrl:text> </successful-report>
This attribute effectively allows the schema author to iterate over the sequence of items returned. While the rule context expression in the example above can (depending on the query language binding) be re-written as
/foo/analyze-string(., "foo")/fn:match
and produce the same result, visit-each enables the expression to be decomposed for clarity.