xslt cannot assign a param with a boolean value within ``

Question

this code is giving me the output test when the expected output should be nothing..

Is it something wrong with my XSLT processor or..? :

    <xsl:template match="/">

         <xsl:param name="IsTextArea">
     <xsl:choose>
        <xsl:when test="false()">
           <xsl:value-of select="true()"/>
        </xsl:when>
        <xsl:otherwise>
           <xsl:value-of select="false()"/>
        </xsl:otherwise>
     </xsl:choose>
  </xsl:param>

  <html>

   <xsl:choose>
   <xsl:when test="$IsTextArea">test
   </xsl:when>
   </xsl:choose>


  </html>
    </xsl:template>

Btw i need a solution for raw XSLT 1.0 (no extensions and stuff like that).

Is it possible to set a boolean parameter for a param in XSLT 1.0?

score 4 · Accepted Answer · answered Jun 09 '11 at 09:11

4

Your parameter is evaluating to a string. You should use:

    <html>
        <xsl:choose>
            <xsl:when test="$IsTextArea = 'true'">
                test
            </xsl:when>
            <xsl:otherwise>
                <xsl:value-of select="$IsTextArea"/>
            </xsl:otherwise>
        </xsl:choose>
    </html>

answered Jun 09 '11 at 09:11

Emiliano Poggi

24,390
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btw is it ok if i set it to `1` and `0` and use `$IsTextArea=1` ? – Pacerier Jun 09 '11 at 16:41
No. As @Michael-Key correctly stated, you are going to have always a string. Try it :)! – Emiliano Poggi Jun 09 '11 at 19:22

score 3 · Answer 2 · answered Jun 09 '11 at 11:16

3

The xsl:value-of instruction converts whatever you give it to a string. So true() becomes "true", and false() becomes "false". When you use a string in a boolean context, any non-empty string becomes true(), while "" becomes false(). So boolean->string->boolean conversion doesn't round-trip. In XSLT 2.0 the answer is to use xsl:sequence instead of xsl:value-of; in 1.0, just use strings like "yes" and "no" to avoid confusion.

answered Jun 09 '11 at 11:16

Michael Kay

156,231
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164

2

sorry could you elaborate on the `xsl:sequence` part? do you mean that we will set a sequence with 1 item which is a boolean? – Pacerier Jun 09 '11 at 16:36

score 0 · Answer 3 · answered Jun 09 '11 at 09:15

0

Shouldn't it be like this:

<xsl:param name="IsTextArea">
 <xsl:choose>
    <xsl:when test="false()">
       <xsl:value-of select="false()"/>
    </xsl:when>
    <xsl:otherwise>
       <xsl:value-of select="true()"/>
    </xsl:otherwise>
 </xsl:choose>

Are think your true and false were out of place.

answered Jun 09 '11 at 09:15

Hasan Fahim

3,875
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nop they aren't out of place. since the test is `false()` IsTextArea should be `false()` then (see the code in my question). and the check should fail. Yet it succeeded and this is verified since `test` was displayed. – Pacerier Jun 09 '11 at 16:35

xslt cannot assign a param with a boolean value within ``

3 Answers3