Re: Re: Keys on multiple element types

Hi Jen,

Thanks for the reply. Justy as I was opening it I thought,
"I bet I'm just missing brackets or something" et voila.

Cheers

Ahmad


At 10:02 AM 2/5/02 +0000, you wrote:
>Hi Ahmad,
>
>> q1. Whats wrong with the stylesheet that it doesnt do this. I think its :-
>> select="RECORDA[generate-id(.
>>
>> but every other path I try ends up with no output.
>
>You're correct that it's that part of the stylesheet that's causing
>the problem. The problem is that you're selecting only the RECORDA
>elements, but you're interested in the RECORDB and RECORDC elements as
>well. One method would be to select the unique ones from all three
>types as follows:
>
>  (RECORDA | RECORDB | RECORDC)
>    [generate-id(.) = generate-id(key('rows', name)[1])]
>
>Or you could just select all the element children of the current FILES
>element, and filter to select only those that appear first in the
>document with a particular name, as follows:
>
>  *[generate-id(.) = generate-id(key('rows', name)[1])]
>
>If you didn't want to list all the RECORD names, you could do a
>similar thing with the definition of the key - make it match those
>elements that are children of the FILES element, no matter what their
>name is:
>
><xsl:key name="rows" match="FILES/*" use="name" />
>
>> q2. Does the vertical bar | mean 'or', and wouldnt it be better to
>> use ',' which I think means 'and'? When I tried ',' it threw up
>> loads of exceptions.
>
>In an expression, the vertical bar (|) means 'union'. In the example
>above, (RECORDA | RECORDB | RECORDC) creates a union of the nodes that
>you select with the individual expressions RECORDA, RECORDB and
>RECORDC, so you get all RECORDA, RECORDB and RECORDC elements.
>
>In a pattern (a match attribute), the vertical bar gives alternative
>patterns. So the pattern RECORDA | RECORDB | RECORDC matches RECORDA,
>RECORDB and RECORDC elements.
>
>The comma (,) isn't an operator in XPath 1.0 (it's only used to
>separate arguments in a function call). You might have been confused
>by recent discussions on this list, because the comma *is* an operator
>in XPath 2.0 (at least in the current WDs), where it's used to
>construct a sequence. In XPath 2.0, if you do (RECORDA | RECORDB |
>RECORDC) then you get the RECORDA, RECORDB and RECORDC elements in
>whatever order they appear. If you do (RECORDA, RECORDB, RECORDC) then
>you get all the RECORDA elements followed by all the RECORDB elements
>followed by all the RECORDC elements. But this doesn't apply in XPath
>1.0 (and XSLT 1.0).
>
>To do 'or', use the operator 'or' (e.g. name = 'foo' or name = 'bar').
>To do 'and', use the operator 'and' (e.g. name = 'foo' and name =
>'bar').
>
>> q.3 If the xml looked like this instead...
>>
>> <FILES>
>>         <RECORDA>
>>         <id>13</id><name>Fred</name><project_name>Building</project_name>
>>         </RECORDA>
>>         <RECORDA>
>>         <id>14</id><name>Fred</name><project_name>Building</project_name>
>>         </RECORDA>
>>         <RECORDB>
>>         <id>15</id><name>Fred</name><project_name>Looking</project_name>
>>         </RECORDB>
>>         <RECORDC>
>>         <id>16</id><name>Harry</name><project_name>Writing</project_name>
>>         </RECORDC>
>> </FILES>
>>
>> How could I get the result to remove multiple copies e.g. to output
>> <id>13</id> but not <id>14</id>
>
>I'm not sure what a 'multiple copy' is in the above. Should the
>RECORDB with id 15 be output or not? If so, you need to define a key
>that indexes the records on both the name of the element (e.g.
>'RECORDA', 'RECORDB' or 'RECORDC') and the name element child (e.g.
>'Fred' or 'Harry'). That kind of key might look like:
>
><xsl:key name="rows" match="FILES/*"
>         use="concat(name(), '+', name)" />
>
>Cheers,
>
>Jeni
>
>---
>Jeni Tennison
>http://www.jenitennison.com/
>
>
> XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
>
>
-------------------------------------------------
Ahmad J Reeves BSc (Hons) MSc (Dist) PhD Student
Information, Media & Communication Research Group
Department of Computer Science
Queen Mary, University of London
E1 4NS
Tel +44(0) 207 882 5257
Fax +44(0) 208 980 6533
http://www.dcs.qmw.ac.uk/imc

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list