Re: [xsl] 'true' or true()

[Michael Kay <mike@xxxxxxxxxxxx>]

On 01/11/2010 21:14, Karl Stubsjoen wrote:
> I have a parameter which will either be, true() by default or 'true'
> (set by user).  Given the name isTrue, how do you properly write the
> if test below:
>
> <xsl:param name="isTrue" select="true()"/>
> <xsl:if test="$isTrue or isTrue=true()">
>
> When user sets the param value = 'false' the above isTrue test still passes.
>
> Thanks,
> Karl..
In XSLT 2.0, declare the expected type of the parameter: <xsl:param 
name="isTrue" select="true()" as="xs:boolean"/>.

The way parameters are passed to a stylesheet depends on the product and 
API you are using: for example from the Saxon command line you will be 
able to pass the string values "true", "false", "0", or "1", but the 
important thing is that whatever is passed, you know you are dealing 
with a boolean, and not (say) a string.

If you can't do this, then validate the parameter within your code:

<xsl:when test="$isTrue='true'">...
<xsl:when test="$isTrue='false'">...
<xsl:otherwise><xsl:message...

Don't just take the effective boolean value. The EBV of all strings 
other than "" is true.

Michael Kay
Saxonica