infinite recursion

bangbangbogi · May 4th, 2006, 05:19 AM

i am trying to extract information from another xml doc. what i have done is to use the document method. The output that results is an infinite recursion. The following is my code

<?xml version="1.0"?>
<xsl:stylesheet
    version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns="http://www.w3.org/TR/REC-html40">

<xsl:output method="html"/>

<xsl:variable name ="CSE4500xml" select="document('tutorialCSE4500.xml')"/>

<xsl:template match="/">
    <xsl:apply-templates select = "units/unit"/>
</xsl:template>

<xsl:template match="unit">
    <HTML>
        <BODY>
        <H2>UNIT TIMETABLE:<xsl:value-of select="name"/></H2>
        Unit Code:
            <xsl:value-of select="code"/>
        <BR/>
        Unit Lecturer:
            <xsl:value-of select="unitLeader"/>
                <table border="1">
                    <th align="left">Tutorial ID</th>
                      <th align="left">Tutor</th>
                      <th align="left">TimeTable</th>
                    <xsl:apply-templates select="$CSE4500xml/tutorialClasses/unit"/>
                        <TD><xsl:value-of select="tutorialClasses/unit/class"/></TD>
                        <TD><xsl:value-of select="tutorialClasses/unit/tutor"/></TD>
                        <TD><xsl:value-of select="tutorialClasses/unit/timetable"/></TD>
                </table>

        </BODY>
    </HTML>
</xsl:template>

</xsl:stylesheet>
I know that the error occurs in the line that I just put in bold. But i do not know how to resolve it. Please help.

Thanks

joefawcett · May 4th, 2006, 05:28 AM

You'll have to show some of the 'tutorialCSE4500.xml' for me to be sure but when you're inside the template that matches unit you make a call to $CSE4500xml/tutorialClasses/unit which then starts a recursion. As unit is the context node you can change the code to:

Code:

<table border="1"><tr>
                    <th align="left">Tutorial ID</th>
                      <th align="left">Tutor</th>
                      <th align="left">TimeTable</th></tr><tr>
                                            <TD><xsl:value-of select="class"/></TD>
                        <TD><xsl:value-of select="tutor"/></TD>
                        <TD><xsl:value-of select="timetable"/></TD></tr>
                </table>

That assumes you want a header for each unit which seems odd. You could move the header code a level up for example.

As I said if you this fails show an example of the source XML and your desired output.

On a side note why are you using the document function instead of just using the standard input method?

--

Joe (Microsoft MVP - XML)

bangbangbogi · May 4th, 2006, 05:50 AM

Hi joe, thanks for the quick reply. the expected output that i want is
UNIT TIMETABLE:

Unit Code:

Unit Lecturer:

Tutorial ID Tutor TimeTable

the source file for the xml is

<?xml version="1.0"?>
<tutorialClasses xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:noNamespaceSchemaLocation="tutorial.xsd">
    <unit>
        <unitCode>CSE4500</unitCode>
        <class ID="t1">
            <tutor>Evi Syukur</tutor>
            <timetable>
                <day>Wednesday</day>
                <time>2-4 PM</time>
            </timetable>
            <studentMark>
                <student ID="s112233441">
                    <name>James Hird</name>
                    <assignments>
                        <assignment no="1">80</assignment>
                        <assignment no="2">90</assignment>
                        <unitTest>75</unitTest>
                    </assignments>
                </student>

mhkay · May 4th, 2006, 05:54 AM

Within this template rule

<xsl:template match="unit">

you are doing

<xsl:apply-templates select="$CSE4500xml/tutorialClasses/unit"/>

which is going to match the template rule you are in, causing a recursive call. There's nothing to terminate the recursion so it goes on for ever.

Change the template to say match="units/unit": this will stop the recursive call. But I don't know what processing you actually want to apply to tutorialClasses/unit - perhaps you need another template rule to define this. Or perhaps you don't want to apply-templates to tutorialClasses/unit at all, since you then go on to output its details using xsl:value-of.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference