RE: [xsl] Selecting similar XML nodes by a sort criteria

[Wendell Piez <wapiez@xxxxxxxxxxxxxxxx>]

Harsh,

At 12:36 PM 10/5/2007, you wrote:
> Another question.
>
> In your code, you have this line:
>
> <xsl:template match="pile">
>    <xsl:for-each
> select="item[generate-id()=generate-id(key('item-by-number',@number)[1])
> ]">
>
> What is the significance of [1] in the generate-id() function call?

As a positional predicate, it filters out all but the first (in 
document order) of the nodes selected in the node set it operates on.

Strictly speaking, in XSLT 1.0 you don't need it, since generate-id() 
will operate on the first node in the set in any case. But it avoids 
an error running under XSLT 2.0, so it's a good habit always to write 
it. Also, it's a tiny bit more legible to a reader who knows that the 
key will return several nodes, but not that generate-id() will 
operate only on the first (under XSLT 1.0).

Cheers,
Wendell


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Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
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