Re: [xsl] Grouping conditions

[Wendell Piez <wapiez at mulberrytech dot com>]

At 03:55 AM 2/7/02, Joerg wrote:
> > Is there a way doing something like:
> > <xsl:choose>
> >   <xsl:when test="@type='101'|'102'|'103'|'104'...">
> > ..
> > </xsl:choose>
> >
> > If this is not possible, is there another way of achieving the same
>result?
> > There are many values that - in this part of the stylesheet - yields the
> > same function, so it is quite cumbersome writing all those "or @type=".
>
>No, it's not possible. We had it already yesterday. '|' means UNION on
>nodesets, 'or' means OR. But @type='101' is no nodeset.

Joerg is correct, but the problem can be eased (in XSLT 1.0) by using a 
"lookup table" pattern, as in

<my:valuelist xmlns:my="http://somenamespace.com";>
   <v>101</v>
   <v>103</v>
   <v>107</v>
   <v>201</v>
   <v>xxx</v>
   <v>whee!</v>
   <v>too many values</v>
   <v>to list in an 'or' sequence</v>
</my:valuelist>

<xsl:variable name="values" select="document('')/*/my:valuelist/v"/>
<!-- bothering with the variable is syntax sugar
      unless you use it more than once -->

and then...

<xsl:when test="@type=$values">

which works by the rule that an equality expression comparing a string to a 
node set is true if the string equals one of the strings in the node set.

While not always worth it, when the value list is really long this can ease 
both code readability and maintenance.

Cheers,
Wendell




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Wendell Piez                            mailto:wapiez@mulberrytech.com
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