I think we need an issection test for IF's as the way to INCLUDE some other section if the requested section isn't there is awful

also means we need a SECTION and section value.

%INCLUDE{
      "%IF{"'%INCLUDE{"%WIDGETSTOPIC%" section="footer-widgets" warn="off" pattern=".*([a-zA-Z]).*"}%' ~ ''"
         else="%WIDGETSTOPIC%"
         then="%SYSTEMWEB%.DefaultWidgets"
      }%"
      section="footer-widgets" 
      warn="on"
      WIDGETSTOPIC="%WIDGETSTOPIC%"
}%

compared to the proposed

%INCLUDE{
      "%IF{"issection %WIDGETSTOPIC%/(section.name='footer-widgets')"
         else="%WIDGETSTOPIC%"
         then="%SYSTEMWEB%.DefaultWidgets"
      }%"
      section="footer-widgets" 
      warn="on"
      WIDGETSTOPIC="%WIDGETSTOPIC%"
}%

---

Two thoughs. (1) Is %TMPL:INCLUDE and option? (2) How about %INCLUDE{"topic1 || topic2 || topic3" ...}% to include either topic1, topic2 or topic3 depending on which is found first in the given prio. That way I could get rid of %WEBCOMPONENT{}% in NatSkin as well, which basically implements what you intend to do in the examples above although not down to section level.

-- MichaelDaum - 23 Jan 2009

If I understand it correctly, you want a "hassection" operator? As in, "does this topic contain this section"?

Sounds like a pretty specialised requirement to me......

-- CrawfordCurrie - 23 Jan 2009

its only specialised because it doesn't exist. Its actually a pretty useful thing for making it trivial for users to over-ride built in functions.

Micha - I like the INCLUDE{"topic1 || topic2 || topic3" ...} idea - but would like to be able to express "topic1/section[wqer] || topic2/section[ewwww] || topic3/section[other]" ... as well..

-- SvenDowideit - 23 Jan 2009

I understand the requirement. I meant it's specialised because it's like a "one off" for a content-access operation. Asking the question "does this section exist" is not a million miles from "get me this section" - and indeed, you have partially invented such a syntax in your examples above. I think what you are really trying to say is something like this:

%INCLUDE{
      "%IF{"exists %WIDGETSTOPIC%/sections[name='footer-widgets']"
         else="%WIDGETSTOPIC%"
         then="%SYSTEMWEB%.DefaultWidgets"
      }%"
      section="footer-widgets" 
      warn="on"
      WIDGETSTOPIC="%WIDGETSTOPIC%"
}%

-- CrawfordCurrie - 23 Jan 2009

I really would like to see more xpath, e.g. %INCLUDE{"topic[expr]/section[expr]"}%

-- MichaelDaum - 23 Jan 2009

Fascinating, Crawford independently identified %WIDGETSTOPIC%/sections[name='footer-widgets'] as plausible syntax, and Foswiki::Address resourcetypes also supports this address notation: 'Web/SubWeb.Topic'/SECTION[name='something']

-- PaulHarvey - 22 Feb 2012