[ZPT] changing the order of operations

[Jamie Heilman]

Charlie Clark wrote:
> On 2003-07-23 at 22:35:12 [+0200], Jamie Heilman wrote:
> > I've mentioned it before and nobody commented on the idea, but I can't 
> > think of a single good reason 'attributes' is executed before 'omit-tag.' 
> > Switching them could yeild speed increases in the case where 'omit-tag' 
> > is true and 'attributes' is expensive.  Am I wrong? Why is this not a 
> > good idea?  When is it useful to generate attributes for a tag and then 
> > throw away the work?
> 
> Sounds more like a programming error to me. Why have tal:attributes and 
> tal:omit-tag in the same tag at all?

You want to itterate over a set of items wrapping some in a tag with
attributes, and some not, based upon external criteria.  Here's bad
example (isPrincipiaFolderish is sick, and <a> is probably not the
most useful tag), but a self-contained example at any rate:
<ul>
<li tal:repeat="o here/objectValues"><a
    tal:define="name o/getId"
    tal:content="string:&gt;${name}&lt;"
    tal:attributes="href string:${o/absolute_url}/;id o/getId"
    tal:omit-tag="not:o/isPrincipiaFolderish">objects</a></li>
</ul>

-- 
Jamie Heilman                   http://audible.transient.net/~jamie/
"...thats the metaphorical equivalent of flopping your wedding tackle 
 into a lion's mouth and flicking his lovespuds with a wet towel, pure 
 insanity..."						-Rimmer