Odd behaviour of DOM

[CubeE101]

I am getting mixed results when trying to select specific nodes...

Using this XML as a reference:

<DocumentRoot>
	<Parent>
		<Child>1</Child>
		<Child>2</Child>
	</Parent>
	<Parent>
		<Child>3</Child>
		<Child>4</Child>
	</Parent>
	<Parent>				
		<Child>5</Child>
		<Child>6</Child>
	</Parent>
</DocumentRoot>

If you don't change the "SelectionLanguage" to "XPath"...
Dom.setProperty "SelectionLanguage", "XPath"
//Parent[0] selects the Parent, rather than the normal //Parent[1]

So... Using XPath as the selection language...

Dom.selectNodes("//Child") Selects all 6 Child Nodes:

<Child>1</Child>
<Child>2</Child>
<Child>3</Child>
<Child>4</Child>
<Child>5</Child>
<Child>6</Child>

If you use one of these:
Dom.selectSingleNode("//Child[1]")
Dom.selectSingleNode("//Child[2]")
It will work fine...

But if you use:
Dom.selectSingleNode("//Child[3]")
Dom.selectSingleNode("//Child[4]")
Dom.selectSingleNode("//Child[5]")
Dom.selectSingleNode("//Child[6]")
It will not select anything...

Though, if you use:
Dom.selectSingleNode("//Parent[2]/Child[1]")
Dom.selectSingleNode("//Parent[2]/Child[2]")
Dom.selectSingleNode("//Parent[3]/Child[1]")
Dom.selectSingleNode("//Parent[3]/Child[2]")
It will select these nodes...

Why does selectNodes("//Child") select all of the Children, but selectSingleNode("//Child[x]") does not...

I could have sworn that these selection methods (Such As //Child[6]) worked in XSL templates before...

Should I be using a different Selection Language for Dom?

Or was I just imagining things...?

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[JontyMC]

The position predicate works on the position of the node in the context of its own node-set rather than that of the node-set you have selected. So:

Dom.selectNodes("//Child[1]")

Will return:

<Child>1</Child>
<Child>3</Child>
<Child>5</Child>

Whereas:

Dom.selectNodes("//Child[3]")

Will not return anything. This is true of XPath, so its the same for DOM and XSL. Hope this explains things.

Jon

"Asteroids do not concern me, Admiral. I want that ship, not excuses.

 

[CubeE101]

That's what I got out of it too...

For some reason, I guess I thought that...
SelectSingleNode("//Child[3]")
Was creating an collection and selecting the third instance the same way that...
SelectNodes("//Child")
Creates a collection...

O-Well...

You can still use:
SelectNodes("//Child")(2)
If needed...

Which I guess would be similar to:

<xsl:stylesheet version="1.0" xmlns:xsl="[URL unfurl="true"]http://www.w3.org/1999/XSL/Transform">[/URL]
  <xsl:template match="/">
    [b]<xsl:variable name="test" select="//Child" />
    <xsl:value-of select="$test[3]" />[/b]
  </xsl:template>
</xsl:stylesheet>

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