Re: [xsl] How to do macro substitution in XPath?

["G. Ken Holman g.ken.holman@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

How about simple Boolean variables?

  <xsl:variable name="LBJ" select="..." as="xsd:boolean"/>
  <xsl:variable name="RM" select="..." as="xsd:boolean"/>
  ...
  <xsl:value-of select="if( $LBJ ) then 'action 1'
                        else if( $RM ) then 'action 2'
                        else 'action 3'"/>

Strictly speaking the as= isn't necessary since the evaulation of the 
expression is Boolean.

I hope this helps.

. . . . Ken

At 2023-12-02 15:36 +0000, Roger L Costello costello@xxxxxxxxx wrote:
> Hi Folks,
>
> I am converting prose like this:
>
> If the title = "Path to Power" and the author = "Robert A. Caro" 
> (Lyndon Baines Johnson (LBJ)), then
> process LBJ as follows
>     action 1
> If the title = "Power Broker" and the author = "Robert A. Caro" 
> (Robert Moses (RM)), then
> process RM as follows
>     action 2
> Neither LBJ nor RM
>     action 3
>
> I need the XPath to be as like the prose as possible.
>
> Suppose the XPath will operate on XML documents like this:
>
> <Book>
>   <Title>Path to Power</Title>
>   <Author>Robert A. Caro</Author>
> </Book>
>
> Below is one approach to writing the XPath. See the XPath in the 
> xsl:value-of element. Notice the use of XML ENTITIES.
>
> The advantage of that approach is the XPath looks like the prose.
>
> The disadvantage with that approach is that ENTITIES are not XPath. 
> I need to stick with pure XPath. What XPath do you recommend?
>
> <?xml version="1.0" encoding="UTF-8"?>
> <!DOCTYPE xsl:stylesheet[
>     <!ENTITY LBJ "((/Book/Title eq 'Path to Power') and 
> (/Book/Author eq 'Robert A. Caro'))">
>     <!ENTITY RM "((/Book/Title eq 'Power Broker') and (/Book/Author 
> eq 'Robert A. Caro'))">
> ]>
> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; 
> version="3.0">
>     <xsl:template match="/">
>         <xsl:value-of select="
>             if &LBJ; then
>                 'action 1'
>             else if &RM; then
>                 'action 2'
>             else if (not((&LBJ;) or (&RM;))) then
>                 'action 3'
>             else
>                 'Error'
>             "/>
>     </xsl:template>
> </xsl:stylesheet>


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