Re: [xsl] Using keys in templates

Subject: Re: [xsl] Using keys in templates
From: Nicolas Mailhot <Nicolas.Mailhot@xxxxxxxxxxx>
Date: Tue, 13 Jul 2004 17:34:54 +0200
Le mar, 13/07/2004 C  15:36 +0100, Jeni Tennison a C)crit :
> Hi Nicolas,
> 
> > 	I'm finding I'm using more and more constructs like :
> >
> > <xsl:key name="dists" match="/release/module/dist" use="@name"/>
> >
> > <xsl:template match="module/dist">
> >  <xsl:variable name="dist" select="@name"/>
> >  <xsl:if test="generate-id(.) = generate-id(key('dists',$dist))">
> >    something
> >  </xsl:if>
> > </xsl:template>
> >
> > 	Would it be possible to kill the if using a syntax like :
> >
> > <xsl:template match="module/dist[some test]" priority="1">
> > </xsl:template>
> >
> > <xsl:template match="module/dist" priority="0"/>
> 
> Yes -- you could use:
> 
>   match="module/dist[generate-id(.) =
>                      generate-id(key('dists', @name))]"
> 
> but it would probably be better to only select the <dist> elements
> that you want to process when you do the <xsl:apply-templates>, as in:
> 
> <xsl:template match="module">
>   <xsl:apply-templates
>     select="dist[generate-id(.) =
>                  generate-id(key('dists', @name))]" />
> </xsl:template>
> 
> <xsl:template match="dist">
>   <!-- this template only processed for the first dist element with
>        each particular name -->
>   ...
> </xsl:template>
> 
> Locating which template to use to process a node takes time, so you
> should try to apply templates to as small a set as possible rather
> than trying to find a template for every node, but only doing
> something with some of them.

Well, you're right but with priorities you can poison the default
template with an xml:message and detect when a node that isn't supposed
to be processed is.

Anyway, thanks for the advice !

-- 
Nicolas Mailhot

Current Thread