RE: [xsl] Understanding axis

[Adam Griffin <agriffin@xxxxxxxxxxxx>]

Much thanks all.

I don't know why I didn't realize the child axis is always implied (I've
even read that part from Kay's book). I started thinking about all the
different types of queries you can do with the axis and I tripped my self
up. I didn't even need anything other than the X[Y] concept Jeni mentioned
(X/Y[Z[local-name()=$v]]  in my case).


-----Original Message-----
From: Jeni Tennison [mailto:jeni@xxxxxxxxxxxxxxxx]
Sent: Tuesday, October 29, 2002 12:03 PM
To: Adam Griffin
Cc: Xsl-List (E-mail)
Subject: Re: [xsl] Understanding axis


Hi Adam,

> I've been learning the use of axis in transformations and I stumbled
> on something that didn't seem to make sense...
>
> local-name( */* )
> local-name( */child::* )
>
> return the same values. I would have thought...
>
> local-name( */child::* )
> local-name( */*/* )
>
> would be the same (which they aren't).

You're right that they aren't. A location path is made up of several
steps, separated by /s. Each step is made up of an axis and a node
test. The default axis, if none is specified explicitly, is child. So:

  */*

is exactly the same as:

  child::*/child::*

> Could somebody help me reason out why it is this way? This seems to
> complicate scenarios where I would only want certain nodes based
> upon their children without changing context. For instance,
> something like:
>
> <xsl:for-each select="*/child::*[local-name()=$v]">
> </xsl:for-each>
>
> read as I only want */* where they have a child named $v.

I think that you want:

  <xsl:for-each select="*/*[*[local-name() = $v]]">
    ...
  </xsl:for-each>

Long version:

  <xsl:for-each select="child::*/child::*[child::*[local-name() = $v]]">
    ...
  </xsl:for-each>

Whenever you say something like "I want X where Y" then you need a
path in the form "X[Y]".
  
Cheers,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/

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