Re: current context preceding-sibling then following-

Did the following message ever make the list?  I posted this a few days back.

current context preceding-sibling then following-sibling


On Fri, 4 Mar 2005 08:14:19 -0700, Karl Stubsjoen <kstubs@xxxxxxxxx> wrote:
> Hello,
> 
> I have complex xpath query which I need help with.  Let me first jump
> to the question which appears to be the hangup:
> 
> the context of the following-sibling following a preceding-sibling
> should result you in the context of the current sibling?
> 
> Often times with a problem like this there is another or better
> approach.  I may have reached the point where I need to try another
> approach.  However, I am so close to the correct solution that I wish
> to persue this just a bit further.  Let me see if I can explain what
> it is I am trying to accomplish:
> 
> The short of it is, I am comparing the preceding-sibling with the
> current.  The preceding-sibling must contain the code "XYZ" when the
> current contains the code "WXY".
> 
> You derive the code to match by a code lookup which is part of the XML
> source.  So, for current you can determine what the
> preceding-sibling's code should be by first looking in the code
> section at the top of the source.
> 
> So, code "WXY" is only valid when the preceding-sibling is code "XYZ"
> (as an example).
> 
> A mock up XML:
> 
> <ROOT>
>  <CODES>
>    <CODE name="WXY">
>        <MATCH>XYZ</MATCH>
>    </CODE>
>  </CODES>
>  <RESULTS>
>      <RESULT code="XYZ" />
>      <RESULT code="WXY"/>
>  </RESULTS>
> </ROOT>
> 
> You might be asking why preceding-sibling followed by following-sibling:
> Because the RESULT code for current is actually an ID which is
> resolved in CODE lookup above (not shown here) ... well, let me just
> add the actual xpath expressions here and maybe it will be easier to
> understand...
> 
> My "hard coded method" works perfectly...
> 
> HARD CODED METHOD:
> =====================================================
> /root/recordset[@rsName='Memberships']/record[field[@fieldname='RefEntryActivityID']=
> ( 33 )]/preceding-sibling::record[field[@fieldname='ExitActivityValue']
> = ( 'W4' ) ]
> 
> Each value within the ( ) needs to be replaced with an appropriate
> xpath statement.
> 
> So, the first ( 33 ) above is replaced with the following:
> 
> /root/recordset[@rsName='Codes']/record[field[@fieldname='Section']= (
> 209 )]/field[@fieldname='ID']
> 
> This XPATH still works great but now I need to replace the ( 209 ),
> but this is not really an issue so we'll skip to the ( 'W4' ).
> 
> The ( 'W4' ) is replaced with:
> 
> /root/recordset[@rsName='Codes']/record[field[@fieldname='ID']= ( 33
> )]/field[@fieldname='Match']
> 
> Now, it is this next ( 33 ) which is the problem!  This value is
> really the current siblings RefEntryActivityID, which the current
> sibling is now out of context? (that is a question).  Notice that ( 33
> ) is part of the right hand side of a preceding-sibling.  So, couldn't
> I just go following-sibling at this point?  Which doesn't appear to be
> working... Here are my 3 attempts at getting this ( 33 ) value from
> the original current context (none work):
> 
> 33 = field[@fieldname='RefEntryActivityID']
> 33 = ./field[@fieldname='RefEntryActivityID']
> 33 = following-sibling::record/field[@fieldname='RefEntryActivityID']
> 
> Thanks for the help!
> 
> Karl