xml - EXSLT custom function causes stylesheet to return "too many nested apply-templates calls" error -
i tried implement "ternary operator" extension function use in stylesheet using exslt's func:function element. compatibility reasons, have use xslt 1.0. came this:
<func:function name="myext:ternary"> <xsl:param name="expr" /> <xsl:param name="iftrue" /> <xsl:param name="iffalse" /> <func:result> <xsl:choose> <xsl:when test="boolean($expr)"><xsl:value-of select="$iftrue"/></xsl:when> <xsl:otherwise><xsl:value-of select="$iffalse" /></xsl:otherwise> </xsl:choose> </func:result> </func:function> and works fine wherever use it. however, tried implement substring-after-last function (from here). code works fine:
<func:function name="myext:substring-after-last"> <xsl:param name="string" select="''"/> <xsl:param name="delimiter" select="$d" /> <func:result> <xsl:choose> <xsl:when test="contains($string, $delimiter)"> <xsl:value-of select="myext:substring-after-last(substring-after($string, $delimiter), $delimiter)"/> </xsl:when> <xsl:otherwise> <xsl:value-of select="$string"/> </xsl:otherwise> </xsl:choose> </func:result> </func:function> this way works:
[…] <func:result> <xsl:if test="not(contains($string, $delimiter))"> <xsl:value-of select="$string"/> </xsl:if> <xsl:if test="not($string='')"> <xsl:value-of select="myext:substring-after-last(substring-after($string, $delimiter), $delimiter)"/> </xsl:if> </func:result> </func:function> … when try implementation using "ternary" function, not work;
this doesn't work:
<func:result> <xsl:value-of select="myext:ternary( contains($string, $delimiter) , not($string = ''), myext:substring-after-last(substring-after($string, $delimiter), $delimiter), $string )"/> </func:result> this method results in stylesheet throwing error @ me:
error @ xsl:apply-templates on line 49 of file:/[my_main_file].xsl: many nested apply-templates calls transformation failed: run-time errors reported i've tried increase java's stack size using -xss16m switch, results in saxon throwing outofmemoryerror (java heap space). data sets send function rather small, don't understand overflow happens , why should necessary me try increase stack size.
what doing wrong?
i tried implement "ternary operator" extension function
use union of position predicate negation predicate variable check else statement:
//var[1] | //var[not //var] use concatenation of mutually exclusive expressions ternary idiom:
concat("(",substring(translate(., "()-", ""), 1, 3), ")", substring(translate(., "()-", ""), 4, 3), "-", substring(translate(., "()-", ""), 7, 4))) in xpath number(true()) 1, while number(false()) 0 , when second argument of substring() function greater actual length of string, empty string returned. hence substring($s1, number(not($condition))*string-length($s1)+1) returns $s1 if $condition true , empty string otherwise. concatenating 2 such expressions in mutually exclusive way gives conditional strings expression.
references
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