XPath 1 query and attributes name

Question

First question: is there any way to get the name of a node\'s attributes?

Answer 1

First question: is there any way to get the name of a node's attributes?

<node attribute1="value1" attribute2="value2" />

Yes: This XPath expression (when node is the context (current) node)):

    name(@*[1])

produces the name of the first attribute (the ordering may be implementation - dependent)

and this XPath expression (when node is the context (current) node)):

    name(@*[2])

produces the name of the second attribute (the ordering may be implementation - dependent).

Second question: is there a way to get attributes and values as value pairs? The situation is the following:

<node attribute1="10" attribute2="0" />

I want to get all attributes where value>0 and this way: "attribute1=10".

This XPath expression (when the attribute named "attribute1" is the context (current) node)):

    concat(name(), '=', .)

produces the string:

    attribute1=value1

and this XPath expression (when the node node is the context (current) node)):

    @*[. > 0]

selects all attributes of the context node, whose value is a number, greater than 0.

In XPath 2.0 one can combine them in a single XPath expression:

    @*[number(.) > 0]/concat(name(.),'=',.)

to get (in this particular case) this result:

    attribute1=10

If you are using XPath 1.0, which is less powerful, you'll need to embed the XPath expression in a hosting language, such as XSLT. The following XSLT 1.0 thransformation :

<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text"/>

  <xsl:template match="/*">
      <xsl:for-each select="@*[number(.) > 0]">
        <xsl:value-of select="concat(name(.),'=',.)"/>
      </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

when applied on this XML document:

<node attribute1="10" attribute2="0" />

Produces exactly the same result:

    attribute1=10

Answer 2

It depends a little bit on the context, I believe. In most cases, I expect you'd have to query "@*", enumerate over the items, and call "name()" - but it may work in some tests.

Re the edit - you can do:

@*[number(.)>0]

to find attributes matching your criteria, and:

concat(name(),'=',.)

to display the output. I don't think you can do both at once, though. What is the context here? xslt? what?