traversing preceding-sibling in reverse doc order

mphare · August 15th, 2007, 04:51 PM

I'm using Oxygen 8.1 and Saxon 8.

I am trying to mine information from a table.

In some cases the cell with the target data is straddled between two or more rows.

So, if I look into the row and the target is not there, I need to look in the row above. If the target is not there, then go up one more. Repeat until the target is found.

I am trying to implement this as a recursive template:

Code:

    <xsl:template match="row" mode="row-proc">
        <xsl:choose>
            <xsl:when test=".//TL1Attribute">
                <xsl:value-of select=".//TL1Attribute"></xsl:value-of>                    
                <xsl:text>#x0A;</xsl:text>
            </xsl:when>
            <xsl:otherwise>
                <xsl:apply-templates select="preceding-sibling::node()[last()]" mode="row-proc"></xsl:apply-templates>
            </xsl:otherwise>
        </xsl:choose>
    </xsl:template>

My reasoning for select="preceding-sibling::node()[last()] is process a selection of the sibling nodes (table rows), going directly to the last() one (should be the row right before the current row???) and recurse into the template.
If the target isn't found then get a new preceding sibling list, get a new last() node and recurse again.

Obviously this isn't working, but I'm not sure why.

It nearly works, except instead of going back one row, it goes all the way back to the first row.

So, what is the best way to process a preceding-sibling list in reverse document order?

Thanks,

- mike

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Michael Hare

mphare · August 16th, 2007, 09:55 AM

I seem to have figured it out using select="preceding-sibling::node()[1]. Using [1], it always takes me to the immediately preceding row in the table.

Does preceding-sibling already put the nodes in reverse document order?

Thanks!

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Michael Hare

mhkay · August 16th, 2007, 12:01 PM

In XSLT 1.0, for-each and apply-templates always process the selected nodes in document order, regardless how they were selected, even if they were selected using a reverse axis. You can process the nodes in reverse document order using <xsl:sort select="position()" data-type="number" order="descending"/>.

As you've discovered, you can get the nearest preceding sibling using preceding-sibling::*[1].

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

mphare · August 16th, 2007, 01:28 PM

Thanks Michael

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GnuPG Key fingerprint = 1AD4 726D E359 A31D 05BF ACE5 CA93 7AD5 D8E3 A876

Michael Hare