Legacy ID: #3861751
Legacy Poster: Sheila Morrissey (smorrissey)
Duplicate values from generate-id() function in an XSL1.0 stylesheet using Saxon B
8.7.3, Java 1.5.0_06 Hello, Mr. Kay. The generate-id() method in Saxon B 8.7.3 is
creating identical values for 2 distinct elements when we execute one of our XSL 1.0
stylesheets. The generate-id() method is being invoked on elements contained in a (Saxon
B 8 7 3) node which has been returned from an extension function. Each node returned
from the extension function contains a single <body> element containing 2
or more <img> elements. We process the information in the
<img> elements, creating 2 elements in our output for each
<img> element in the node returned from the extension function. One of
these output elements contains an IDREF attribute, and the other contains an ID
attribute. The values for the IDREF and ID attributes in the paired output elements are
computed by applying generate-id() to the same input <img> element. The
first time the template in question is invoked (from a template matching element name
‘tihtml’), it is passed 2 <img> elements in succession from a template
which is processing the <body> element in the node returned from the
extension function in the ‘tihtml’ template. It correctly produces the 2 pairs of output
elements, and there is no problem with duplicate ID values being created with the
generate-id() method. The problem template is then subsequently invoked from a template
matching element name ‘abshtml’, which in turn invokes a template to process the
<body> element returned from the extension function. This second
<body> element (contains 10 <img> elements, all with
attribute values distinct from the <img> elements returned previously by
the extension function. When the generate-id() method is invoked on the first of these
new <img> elements, it generates the same value as it did for the last of
the 2 <img> elements in the first invocation of the template. Thereafter,
however, as the template processes the remaining 9 <img> elements, it
correctly produces unique values when generate-id() is invoked. Here is the template
which is creating the duplicate id values: <xsl:template
match="img" mode="html"> <xsl:param
name="pAsBreak" select="false()"/>
<xsl:variable name="commentValue"> <xsl:for-each
select="preceding-sibling::comment()[1] |
preceding-sibling::img[1]"> <xsl:sort
select="position()" data-type="number"
order="descending"/> <xsl:if test="position() =
1"> <xsl:if test="not(name() = 'img')">
<xsl:choose> <xsl:when test="contains(., 'MATH:
')"> <xsl:value-of select="substring-after(., 'MATH:
')"/> </xsl:when> <xsl:otherwise>
<xsl:value-of select="."/>
</xsl:otherwise> </xsl:choose> </xsl:if>
</xsl:if> </xsl:for-each> </xsl:variable>
<inline-formula> <xsl:if test="string-length(@src)
> 0"> <inline-graphic
mimetype="image"> <xsl:attribute
name="alternate-form-of"><xsl:value-of
select="generate-id()"/></xsl:attribute>
<xsl:attribute name="xlink:href"><xsl:value-of
select="concat('localfile:',
@src)"/></xsl:attribute> </inline-graphic>
</xsl:if> <tex-math> <xsl:attribute
name="id"><xsl:value-of
select="generate-id()"/></xsl:attribute>
<xsl:choose> <xsl:when
test="normalize-space($commentValue)"> <xsl:value-of
select="$commentValue"/> </xsl:when>
<xsl:otherwise> <xsl:value-of
select="@alt"/> </xsl:otherwise>
</xsl:choose> </tex-math> </inline-formula>
</xsl:template> Here is the chain of invocation for the first element:
<!-- ============================================================= -->
<!-- "tihtml" --> <!--
============================================================= --> <!--
--> <xsl:template match="tihtml">
<xsl:text>
</xsl:text>
<article-title> <xsl:variable name="path">
<xsl:apply-templates select="."
mode="get-full-xpath" /> </xsl:variable>
<xsl:variable name="result"
select="jtidy:convert($tidyInstance, ., false(), $path)"/>
<xsl:choose> <xsl:when test="$result">
<xsl:apply-templates select="$result"
mode="html"> <xsl:with-param
name="pAsBreak" select="true()"/>
</xsl:apply-templates> </xsl:when>
<xsl:otherwise> <xsl:call-template
name="ConPrepMessage"> <xsl:with-param
name="msgNum" select="'AMS704'"/>
<xsl:with-param name="scriptName"
select="$SCRIPT_NAME"/> <xsl:with-param
name="message"><xsl:value-of
select="name()"/></xsl:with-param>
</xsl:call-template> </xsl:otherwise>
</xsl:choose> </article-title> </xsl:template>
The $result variable is a Saxon 8 node containing the <body> element which
contains the <img> elements. The apply-templates therefore matches first
on <body> element, mode=’html’. That template is as follows:
<xsl:template match="body"
mode="html"> <xsl:param
name="pAsBreak" select="false()"/>
<xsl:param name="expectP"
select="false()"/> <xsl:choose> <xsl:when
test="$expectP"> <xsl:choose> <xsl:when
test="p"> <xsl:apply-templates
mode="html"> <xsl:with-param
name="pAsBreak" select="$pAsBreak"/>
</xsl:apply-templates> </xsl:when>
<xsl:otherwise> <p> <xsl:apply-templates
mode="html"> <xsl:with-param
name="pAsBreak" select="$pAsBreak"/>
</xsl:apply-templates> </p> </xsl:otherwise>
</xsl:choose> </xsl:when> <xsl:otherwise>
<xsl:choose> <xsl:when test="p">
<xsl:apply-templates select="p/*"
mode="html"> <xsl:with-param
name="pAsBreak" select="$pAsBreak"/>
</xsl:apply-templates> </xsl:when>
<xsl:otherwise> <xsl:apply-templates
mode="html"> <xsl:with-param
name="pAsBreak" select="$pAsBreak"/>
</xsl:apply-templates> </xsl:otherwise>
</xsl:choose> </xsl:otherwise> </xsl:choose>
</xsl:template> The <img> elements contained in the body are
then processed, via appy-templates, mode=”html” by the “problem” template listed above.
For the second template (the one which ultimately results in production of duplicate
IDs), the chain of invocation is as follows: <!--
============================================================= --> <!--
"abshtml" --> <!--
============================================================= --> <!--
--> <xsl:template match="abshtml">
<xsl:choose> <xsl:when
test="string-length(normalize-space(.)) > 0">
<xsl:variable name="path"> <xsl:apply-templates
select="." mode="get-full-xpath" />
</xsl:variable> <xsl:variable name="result"
select="jtidy:convert($tidyInstance, normalize-space(.), true(),
$path)"/> <xsl:if test="$result">
<xsl:text>
</xsl:text> <abstract>
<xsl:text>
</xsl:text>
<title><x
x-type="archive"><xsl:value-of
select="$ABSTRACT_TITLE"/></x></title>
<xsl:apply-templates select="$result"
mode="abshtml"/> </abstract>
</xsl:if> </xsl:when> <xsl:otherwise>
<xsl:call-template name="ConPrepMessage">
<xsl:with-param name="msgNum"
select="'AMS702'"/> <xsl:with-param
name="scriptName" select="$SCRIPT_NAME"/>
<xsl:with-param name="message"><xsl:value-of
select="name()"/></xsl:with-param>
</xsl:call-template> </xsl:otherwise>
</xsl:choose> </xsl:template> The $result variable is a
Saxon 8 node containing the <body> element which contains the 10
<img> elements. The apply-templates therefore matches first on
<body> element, mode= ‘abshtml’. That template is as follows:
<xsl:template match="body"
mode="abshtml"> <xsl:param
name="pAsBreak" select="false()"/>
<xsl:for-each select="node()">
<xsl:choose> <xsl:when test="self::text() and
not(normalize-space(.))"/> <xsl:when test="name(.) = 'p'
or name(.) = 'div' or name(.) = 'br' or name(.) = 'address'">
<xsl:apply-templates select="."
mode="html"> <xsl:with-param
name="pAsBreak" select="$pAsBreak"/>
</xsl:apply-templates> </xsl:when>
<xsl:otherwise> <xsl:if test="position() = 1 or
name(preceding-sibling::node()[1]) = 'p' or name(preceding-sibling::node()[1]) = 'div'
or name(preceding-sibling::node()[1]) = 'br' or name(preceding-sibling::node()[1]) =
'address'"> <xsl:text
disable-output-escaping="yes"><p></xsl:text>
</xsl:if> <xsl:apply-templates select="."
mode="html"> <xsl:with-param
name="pAsBreak" select="$pAsBreak"/>
</xsl:apply-templates> <xsl:if test="position() = last()
or name(following-sibling::node()[1]) = 'p' or name(following-sibling::node()[1]) =
'div' or name(following-sibling::node()[1]) = 'br' or name(following-sibling::node()[1])
= 'address'"> <xsl:text
disable-output-escaping="yes"></p></xsl:text>
</xsl:if> </xsl:otherwise> </xsl:choose>
</xsl:for-each> </xsl:template> This template then again
invokes the problem template via the apply-templates mode=”html’’ This is when the
duplicate ID value is generated. Any help you could give us on this matter would be
greatly appreciated. Regards, Sheila Sheila M. Morrissey Portico 228 Alexander Street
Princeton NJ 08540 USA 609 258 9173 http://portico.org/ http://www.ithaka.org/
Duplicate values from generate-id() function 
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