In my system there is a servlet that requests info from a db and then makes an xml file with user info. In that info is a phone number. If the user's phone number is marked as private then (xxx) xxx-xxxx is returned. I'm trying to make my xsl so that instead of displaying x's it displays nothing. This is what I'm trying:


<xsl:variable name="phone">
 <xsl:value-of select="response/bio_contents/phone_number" disable-output-escaping="yes" />
</xsl:variable>
<xsl:variable name="isempty">
 <xsl:value-of select="compare('(xxx) xxx-xxxx',$phone)"/>
</xsl:variable>

<xsl:if test="$isempty != 1">
 <xsl:value-of select="$phone"/>
</xsl:if>

It seems to be valid but it's causing an error because nothing on my page shows up. If I delete this, all the rest of the user's information shows just fine.

A few points.

(a) don't use disable-output-escaping. It's completely undefined when writing to a temporary destination, as here, and it certainly does no good. And it makes you like like a programmer who will try anything rather than resort to reading the manual.

(b) don't use the construct

<xsl:variable name="x">
  <xsl:value-of select="y"/>
</xsl:variable>

when you mean <xsl:variable name="x" select="y"/>.

Unless of course you get paid more for writing three lines of code where one will do, or for writing a program that takes three times longer to execute.

(c) don't use the compare() function to test for equality. compare() is an XSLT 2.0 function that returns -1 if a<b, 0 if a=b, and +1 if a>b. I think you're testing for equality, so that should give 0, not 1 as the answer, but you can test for equality using "=".

(d) don't post here saying that something causes an error without saying what the error is. You might not understand it, but the chances are that someone else does.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

You should be checking $isempty != 0, not 1 as compare returns -1, 0 or 1.

Other than that I'm not sure as you don't say what the error is.

I think the following probably does the same on one line though.

<xsl:value-of select="response/bio_contents/phone_number[text() != '(xxx) xxx-xxxx']"/>

/- Sam Judson : Wrox Technical Editor -/

I didn't have an error to give you. A servlet takes the page and the xsl and does the transformation, if there is an error, it just outputs "user not available" and I don't have immediate access to the logs.

Anyway, I got it working using contains instead of compare. Must have been because of the 2.0 issue.

I didn't make the XSL, it's just a standard one we use, but one subweb didn't like having x's for no phone number, they wanted nothing. So I was just looking for a quick solution, which is working now.

Is that construct bad because it makes for messy code, or is there a performance difference?

If you mean the variable declaration then both.

--

Joe (Microsoft MVP - XML)