Re: [xsl] what's the best way to validate input parameters to a stylesheet?

["Wendell Piez wapiez@xxxxxxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hey Chris,

You could pull the logic into a static variable:

<xsl:variable name="doc-fails" as="xs:boolean" select="matches($from.att,
'^@\w+=\w+$') and matches($to.att, '^@\w+=\w+$')"/>

then

<xsl:template match="/[$doc-fails]">
  ... this document fails ...
</xsl:template>

Make the @priority explicit if you want to give a better hint.

It's really factoring out the choose into a template match in the normal
way. You could even do it without the variable for maximum mystery.

Cheers, Wendell



On Fri, Mar 19, 2021 at 5:58 PM Chris Papademetrious
christopher.papademetrious@xxxxxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Hello! Ibve got a stylesheet that takes two string parameters:
>
>
>
> <?xml version="1.0" encoding="UTF-8"?>
>
> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
> version="2.0">
>
>
>
>   <xsl:param name="from.att" as="xs:string"/>
>
>   <xsl:param name="to.att"   as="xs:string"/>
>
>
>
> Both parameters are expected to be strings in the form of
>
>
>
> @attributename=value
>
>
>
> At first I tried adding a check at the top level of the stylesheet:
>
>
>
> <xsl:if test="not(matches($from.att, '^@\w+=\w+$') and matches($to.att,
> '^@\w+=\w+$'))">
>
>   <xsl:message terminate="yes">Input parameters must be in the form
> '@attributename=value'.</xsl:message>
>
> </xsl:if>
>
>
>
> but <xsl:if> isnbt allowed at the top level of a stylesheet.
>
>
>
> So for now Ibm doing this in a bdummyb root element template that
doesnbt
> do anything:
>
>
>
>   <!-- this doesn't actually do anything other than validate our input
> parameters -->
>
>   <xsl:template match="/" priority="20">
>
>     <xsl:choose>
>
>       <xsl:when test="matches($from.att, '^@\w+=\w+$') and
> matches($to.att, '^@\w+=\w+$')">
>
>         <xsl:next-match/>
>
>       </xsl:when>
>
>       <xsl:otherwise>
>
>         <xsl:message>Input parameters must be in the form
> '@attributename=value'.</xsl:message>
>
>         <xsl:copy-of select="."/>
>
>       </xsl:otherwise>
>
>    </xsl:choose>
>
>   </xsl:template>
>
>
>
> but I feel like therebs probably a better way. Is there?
>
>
>
> -----
> Chris Papademetrious
>
> Tech Writer, Implementation Group
>
> (610) 628-9718 home office
>
> (570) 460-6078 cell
>
>
> XSL-List info and archive <http://www.mulberrytech.com/xsl/xsl-list>
> EasyUnsubscribe <http://lists.mulberrytech.com/unsub/xsl-list/174322> (by
> email <>)
>


--
...Wendell Piez... ...wendell -at- nist -dot- gov...
...wendellpiez.com... ...pellucidliterature.org... ...pausepress.org...
...github.com/wendellpiez... ...gitlab.coko.foundation/wendell...