Hi,
> -----Original Message-----
> From: Mark Vakoc [mailto:[EMAIL PROTECTED]
> ----- Original Message ----
> From: "Buchcik, Kasimier" <[EMAIL PROTECTED]>
>
>
> > While implementing the cleanup of temporary tree fragments directly
> > when an instruction exits, I noticed that we'll get problems if
> > trying to do the same for extension elements. With the current
> > implementation of EXSLT's functions, this won't work:
>
> Ah, you just refreshed my memory a bit. I actually perform
> the external data gathering in an extension element,
> assigning it to a variable for processing.
>
> <xsl:variable name="results">
> <my:sql table="some_table">
> <columns>.....</columns>
> <selection>....</selection>
> </my:sql>
> </xsl:variable>
>
> <xsl:for-each select="exsl:node-set($results)/row">
> <xsl:variable name="results2">
> <my:sql table="some_other_table">....</my:sql>
> </xsl:variable>
> <xsl:for-each select="exsl:node-set($results2)/row">
> ....
>
> So the main problem I had, if I remember correctly, was that
> although the variable results2 would go out of scope with
> each of iteration of the first <xsl:for-each>
> it would not get freed until the parent template (i.e.
> xsltApplyOneTemplate) was exited. The workaround was to
> always call into a named template directly under
> each xsl:for-each that did any external data fetching, so the
> lifespan of the nested sql results would be reduced.
>
> Again, probably a corner case here, though I'm probably not
> the only one using extension elements and functions to gather
> significant amounts of data.
I see. This must have been the case before I started looking at the
code, since the mechanism I was confronted with calls
xsltApplyOneTemplate() for every iteration of xsl:for-each. Also
for every xsl:variable xsltApplyOneTemplate() is called with the
variable instruction itself. Or, in other words, xsltApplyOneTemplate()
was not only called for an xsl:template but for every "template"
(or sequence constructor in XSLT 2.0 terms).
Hmm, while writing this, I now wonder why the EXSLT function
implementation works at all.
Example:
<func:function name="foo">
<func:result>
<foo/>
</func:result>
</func:function>
The exsltFuncFunctionFunction() calls xsltApplyOneTemplate() to
process the content, which is <func:result>; this should free the
tree fragment inside <func:result> on exit of xsltApplyOneTemplate().
It seems I'm still missing something here. I'll look into this.
Regards,
Kasimier
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