Re: Showing unique rows at multiple levels

> Hi,
>
> Your expression "//book[(bookshelf =
> $bookshelfVar)]/author[not(.=preceding::author)]" is too strict (the
> predicate too tolerant). You need to limit the preceding::author part to
> match only authors that are on the same bookshelf. Similar thing for the
> publisher. :-)

>
> Besides, I would recommend trying to use keys and grouping techniques
> like the Muenchian method. Something like:
>

Regards,
Glen

Actually, I meant something like:

<xsl:stylesheet version="1.0"
       xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:key name="bookshelves" match="bookshelf" use="." />
<xsl:key name="authors"     match="author"    use="concat(../bookshelf,
'-', .)" />
<xsl:key name="publishers"  match="publisher" use="concat(../bookshelf,
'-', ../author, '-', .)" />

<xsl:template match="books">
    <xsl:apply-templates select="book/bookshelf">
         <xsl:sort select="."/>
    </xsl:apply-templates>
</xsl:template>

<xsl:template match="bookshelf">
<xsl:if test="generate-id(.) = generate-id(key('bookshelves',
.)[1])">
<xsl:variable name="bookshelfVar" select="."/>
<xsl:variable name="authorVar" select="../author"/>
<xsl:text>&#10;</xsl:text>
<xsl:value-of select="."/>
<xsl:apply-templates select="/books/book[(bookshelf =
$bookshelfVar)]/author">
<xsl:sort select="."/>
</xsl:apply-templates>
</xsl:if>
</xsl:template>

<xsl:template match="author">
    <xsl:if test="generate-id(.) = generate-id(key('authors',
concat(../bookshelf, '-', .))[1])">
        <xsl:variable name="bookshelfVar" select="../bookshelf"/>
        <xsl:variable name="authorVar" select="."/>

        <xsl:text>&#10;--</xsl:text>
        <xsl:value-of select="."/>

        <xsl:apply-templates select="/books/book[(bookshelf =
$bookshelfVar) and (author = $authorVar)]/publisher">
            <xsl:sort select="."/>
        </xsl:apply-templates>
    </xsl:if>
</xsl:template>

<xsl:template match="publisher">
    <xsl:if test="generate-id(.) = generate-id(key('publishers',
concat(../bookshelf, '-', ../author, '-', .))[1])">
        <xsl:text>&#10;----</xsl:text>
        <xsl:value-of select="."/>
    </xsl:if>
</xsl:template>

</xsl:stylesheet>

It replaces // by explicit paths and preceding axis by keyed indexes..

Kind regards,
Geert

Drs. G.P.H. Josten
Consultant

Daidalos BV
Source of Innovation
Hoekeindsehof 1-4
2665  JZ  Bleiswijk
Tel.: +31 (0) 10 850 1200
Fax: +31 (0) 10 850 1199
www.daidalos.nl
KvK 27164984

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Van: Geert Josten [mailto:geert.josten@xxxxxxxxxxx] Verzonden: donderdag 5 oktober 2006 8:13
Aan: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Onderwerp: RE: Showing unique rows at multiple levels

Hi,

Your expression "//book[(bookshelf =
$bookshelfVar)]/author[not(.=preceding::author)]" is too strict (the predicate too tolerant). You need to limit the preceding::author part to match only authors that are on the same bookshelf. Similar thing for the publisher. :-)

Besides, I would recommend trying to use keys and grouping techniques like the Muenchian method. Something like:

(at top-level)

<xsl:key name="bookshelfs" match="bookshelf" use="." /> <xsl:key name="authors" match="author" use="concat(../bookshelf, '-', .)" />

(inside bookshelf template)

<xsl:for-each select="key('bookshelfs', .)[1]">
 ...
</xsl:for-each>

(inside author template)

<xsl:for-each select="key('authors', concat(../bookshelf, '-', .)[1]">
 ...
</xsl:for-each>

Probably a lot quicker if your data file becomes larger. Using // is usually very expensive in that case..

Kind regards,
Geert