Re: [xsl] A challenge.. Group Periods of Data (1..5, 2..8, 4..9) (10..12; 10..14)

[Karl Stubsjoen <kstubs@xxxxxxxxx>]

David, WOW!  ... i'm still trying to figure out how it works ...
So, can you explain?  This is like magic.. I've been trying to figure
it out, but can't.
Things I don't get:

1)  Variable e2 select.
select="@period_end[. > $e]|$e[. >= current()/@period_end]"

How does the pipe work here and is this only evaluating the current B
element, or evaluating all @period_end(s)?

2)  Right off the bat (first iteration), I don't understand how you
determine the period attribute "ends" value.

3)  Variable g select, what does this get you, the ancestor record?
select="/.."

4) The copy of within the element period within the otherwise then the
apply templates rule, it obviously creates the new <period/> element,
but I don't see how your recursive template call inserts the
"members", I don't get how you are preserving the member element of
period.

Thanks again.

Karl

On 5/4/05, David Carlisle <davidc@xxxxxxxxx> wrote:
>
>
> using Dimitre's test file (which has sorted input) here's a simplish
> pure xslt1 solution, no node set or other extensions.
>
>
> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
>                version="1.0">
>
> <xsl:output indent="yes"/>
>
> <xsl:template match="A">
> <result>
> <xsl:apply-templates select="B[1]"/>
> </result>
> </xsl:template>
>
> <xsl:template match="B">
> <xsl:param name="b" select="@period_begin"/>
> <xsl:param name="e" select="@period_end"/>
> <xsl:param name="g" select="/.."/>
> <xsl:variable name="e2" select="@period_end[. &gt; $e]|$e[. &gt;=
current()/@period_end]"/>
> <xsl:choose>
> <xsl:when test="../B[@period_begin &lt;=$e2 and @period_end &gt; $e2]">
> <xsl:apply-templates select="following-sibling::B[1]">
>  <xsl:with-param name="b" select="$b"/>
>  <xsl:with-param name="e" select="$e2"/>
>  <xsl:with-param name="g" select="$g|."/>
> </xsl:apply-templates>
> </xsl:when>
>  <xsl:otherwise>
>  <period begins="{$b}" ends="{$e2}">
>    <xsl:copy-of select="$g|."/>
>  </period>
> <xsl:apply-templates select="following-sibling::B[1]"/>
> </xsl:otherwise>
> </xsl:choose>
> </xsl:template>
>
> </xsl:stylesheet>
>
>
> <A>
>        <B period_begin="1" period_end="5"/>
>        <B period_begin="2" period_end="7"/>
>        <B period_begin="3" period_end="10"/>
>        <B period_begin="4" period_end="12"/>
>        <B period_begin="14" period_end="16"/>
>        <B period_begin="16" period_end="20"/>
>        <B period_begin="16" period_end="30"/>
>        <B period_begin="32" period_end="33"/>
>        <B period_begin="33" period_end="38"/>
> </A>
>
> $ saxon period.xml period.xsl
> <?xml version="1.0" encoding="utf-8"?>
> <result>
>   <period begins="1" ends="12">
>      <B period_begin="1" period_end="5"/>
>      <B period_begin="2" period_end="7"/>
>      <B period_begin="3" period_end="10"/>
>      <B period_begin="4" period_end="12"/>
>   </period>
>   <period begins="14" ends="30">
>      <B period_begin="14" period_end="16"/>
>      <B period_begin="16" period_end="20"/>
>      <B period_begin="16" period_end="30"/>
>   </period>
>   <period begins="32" ends="38">
>      <B period_begin="32" period_end="33"/>
>      <B period_begin="33" period_end="38"/>
>   </period>
> </result>
>
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