Re: xpath query

That helps alot.
Thank you

Sean

On Jan 20, 2008 11:05 AM, Colin Paul Adams <colin@xxxxxxxxxxxxxxxxxx> wrote:
> >>>>> "Sean" == Sean Tiley <sean.tiley@xxxxxxxxx> writes:
>
>    Sean> I guess fundamentally I do not understand how the processor
>    Sean> applies the stylesheet templates to the xml document.
>
>    Sean> Say I have the followng XML
>
>    Sean> <root> <file name="test.java"> <error line="4"
>    Sean> message="Message1" severity="2"/> <error line="67"
>    Sean> message="Message2" severity="4"/> </file> <file
>    Sean> name="code.java"> <error line="2" message="Message1"
>    Sean> severity="2"/> <error line="54" message="Message2"
>    Sean> severity="4"/> <error line="122" message="Message1"
>    Sean> severity="2"/> </file> </root>
>
>    Sean> Then as the processor processes the tree for this xml file,
>    Sean> it finds the <root> element, then looks for a template that
>    Sean> matches it.  It would find the identity template and invoke
>    Sean> this template.  At this point, what does it put out to the
>    Sean> result tree if anything?
>
>
> A recap of what the identity template looks like. here is one form.
>
>  <xsl:template match="@* | node()">
>       <xsl:copy>
>           <xsl:apply-templates select="@* | node()"/>
>       </xsl:copy>
>   </xsl:template>
>
> If this is the template that proves to be the best match for your
> element named root, then the processor will perform an xsl:copy of
> that element.
>
> From the XSLT 2.0 recommendation:
>
> "The xsl:copy  instruction provides a way of copying the context
> item. If the context item is a node, evaluating the xsl:copy
> instruction constructs a copy of the context node, and the result of
> the xsl:copy instruction is this newly constructed node. By default,
> the namespace nodes of the context node are automatically copied as
> well, but the attributes and children of the node are not
> automatically copied."
>
> So the processor will notionally now create an empty
> <root>
>
> </root>
>
>  element in the result tree.
> It then looks at the body of the xsl:copy instruction, to see what
> else it has to do.
>
> In this case, it is instructed to apply templates that match all the
> elements attributes and child nodes.
>
> In this case there are no attributes, but we do have some element
> children (there may also be white-space text nodes, depending on
> whether or not they have been stripped - let's assume none for the
> moment).
>
> The first element child it finds is the element:
>
> <file name="test.java">
>
> So it will then try to find a template that matches this node. If you
> don't have any more specific templates to match this, then the
> identity template will match it.
>
> So it will copy it (execute the xsl:copy instruction in the
> template).
> Now the result tree looks like:
>
> <root>
>  <find>
>  </find>
> </root>
>
> At which point it will try to execute the body of the xsl:copy
> again. This time it finds and attribute node (name="test.java"), so it
> will try to match that. Again, if you have no more specific template
> than the identity template, the identity template will match. So the
> processor will execute the xsl:copy instruction in the template, and
> the result tree will now look like this:
>
> <root>
>  <find name="test.java">
>  </find>
> </root>
>
> At which point it will try to execute the body of the xsl:copy
> again. This time it finds no attributes or child nodes (an attribute
> node has no children or attribtes), so it finishes that invocation of
> the identity template, and resumes on the previous one where it left
> off (matching the attribute name in the find element). It will
> discover that find has no more attributes or child nodes, so it will
> finish exceuting that invocation of the identity template too, and
> resumes on the previous one where it left off (matching the find child
> of the root element). It will look for further children of the root
> element, and will find the first error element, so it will attempt to match
> that.
>
> Again, if you have no more specific template
> than the identity template, the identity template will match. Etc. etc.
> --
> Colin Adams
> Preston Lancashire
>
>



-- 
Sean Tiley
sean.tiley@xxxxxxxxx