[XSL] Obtaining an attribute from self or ancestor

What I want to achieve is to have an XSL that:
- takes a $id variable externally from a PHP script
- finds the node with @id=$id
- outputs the value "@attr" attribute IF PRESENT, otherwise the parent's
"@attr" attribute IF PRESENT, otherwise the grandparent's... recursively
traversing from parent to parent, until an @attr value is found
>
This won't work for some nodes:
>
<?xml version="1.0"?>
<xsl:stylesheet version="1.0">
<xsl:output method="html" />

<xsl:template match="root">
<xsl:apply-templates select="//node[@id=$id]" />
</xsl:template>
<xsl:template match="node">
<xsl:choose>
<xsl:when test="not(@attr)"><xsl:apply-templates ".."
/></xsl:when>

Ebenezer wrote:
>>
You need to define the id parameter
<xsl:param name="id"/>

That is not the correct syntax, you need
<xsl:apply-templates select=".."/>

Also it is not clear what you want to do if you do not find a 'node'
ancestor element with an 'attr' attribute.
If you walk up to the 'root element then the template matching that will
lead to infinite recursion. So perhaps you should better use
<xsl:apply-templates select="parent::node"/>

Or if you want to walk up to the 'root' element as well you need a mode
e.g.
<xsl:apply-templates select=".." mode="attribute-check"/>
>
and then you need to add that mode parameter to the template e.g.

<root attr="first">
<node id="1" attr="mike">
<node id="2" />
<node id="3" attr="dave" />
</node>
<node id="4">
<node id="5" attr="peter" />
</node>
</root>
>
What I want to achieve is to have an XSL that:
- takes a $id variable externally from a PHP script
- finds the node with @id=$id
- outputs the value "@attr" attribute IF PRESENT,
otherwise the parent's "@attr" attribute IF PRESENT,
otherwise the grandparent's... recursively traversing from
parent to parent, until an @attr value is found

Hello!
>
Let's suppose we have an XML with some nested NODE nodes:
>
<root attr="first">
<node id="1" attr="mike">
<node id="2" />
<node id="3" attr="dave" />
</node>
<node id="4">
<node id="5" attr="peter" />
</node>
</root>
>
What I want to achieve is to have an XSL that:
- takes a $id variable externally from a PHP script
- finds the node with @id=$id
- outputs the value "@attr" attribute IF PRESENT, otherwise the parent's
"@attr" attribute IF PRESENT, otherwise the grandparent's... recursively
traversing from parent to parent, until an @attr value is found
>
This won't work for some nodes:
>
<?xml version="1.0"?>
<xsl:stylesheet version="1.0">
<xsl:output method="html" />
<xsl:template match="root">
<xsl:apply-templates select="//node[@id=$id]" />
</xsl:template>
<xsl:template match="node">
<xsl:choose>
<xsl:when test="not(@attr)"><xsl:apply-templates ".." /></xsl:when>
<xsl:otherwise><xsl:value-of select="@attr" /></xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

>Actually, this can be achieved with a single XPath one-liner (even without
>XSLT being involved).
>
>Use:
>
//node[@id = $id]/ancestor-or-self::*[@attr][1]/@attr

In article <490139f9$0$17067$6e1ede2f@read.cnntp.org>,
Dimitre Novatchev <dnovatchev@cnntp.orgwrote:
>>
Or, if you find it clearer not to repeat @attr:
>
(//node[@id = $id]/ancestor-or-self::*/@attr)[last()]
>

>This may be "clearer" but risks to be less efficient.
>
>Using [1] in a reverse axis is a strong optimization hint and a clever XPath
>engine will not traverse the whole way up -- it wil just stop on the first
>self-or-ancestor element found that has an "attr" attribute.