[xsl] testing for existence of content before processing

I am working with a table of contents that I am converting into a table, 
placing the contents of the toc into one column of the table and inserting 
certain content in the last column of each row, depending upon the position and 
content of certain entries. All is great until I get to situations in which the 
content depends upon the existence or non-existence of a certain item in the 
toc.

Given this incoming xml... 

<chapter name="Chapter 1">
        <tocItem><title>Lesson A</title><pages>pp. 4-5</pages></tocItem>
        <tocItem><title>Lesson B</title><pages>pp. 6-7</pages></tocItem>
        <tocItem><title>Lesson C</title><pages>pp. 8-9</pages></tocItem>
        <tocItem><title>Lesson D</title><pages>pp. 10-11</pages></tocItem>
        <tocItem><title>Lab</title><pages>p. 12</pages></tocItem>
        <tocItem><title>Test</title><pages>pp. 13-14</pages></tocItem>
</chapter>

I would put a review item in the same row as <title>Lab</title>.

Given this chapter...

<chapter name="Chapter 2">
        <tocItem><title>Lesson A</title><pages>pp. 15-16</pages></tocItem>
        <tocItem><title>Lesson B</title><pages>pp. 16-17</pages></tocItem>
        <tocItem><title>Lesson C</title><pages>pp. 18-19</pages></tocItem>
        <tocItem><title>Lesson D</title><pages>pp. 20-21</pages></tocItem>
        <tocItem><title>Test</title><pages>p. 22</pages></tocItem>
</chapter>

I would put the review item in the same row as Lesson D.

My question, how do I test for the existence or non-existence of the Lab before 
I start processing the chapter? If the review always fell in the second-to-last 
row, I would have no problem. But sometimes the Lab falls two or three rows 
before the last row.

Currently, I am using a combination of position() tests and predicates to 
populate the rows. For example:

<xsl:for-each select="tocItem">
        <xsl:choose>
                <xsl:when test="position()=1">
                        <!--place pretest-->
                </xsl:when>
                <xsl:when test="position()=last()">
                        <!--place posttest-->
                </xsl:when>
                <xsl:when test="self::tocItem[title = 'Lab']">
                        <!--place review-->
                </xsl:when>
                <xsl:otherwise>
                        <!--place generic row info-->
                </xsl:otherwise> 
        </xsl:choose>

As you can see, a chapter with no Lab will receive no review.

Perhaps my approach is wrong-headed. Any assistance would be most appreciated.

Terry




--~------------------------------------------------------------------
XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail: <mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--