[pmwiki-users] Test if PTV is set (:if {$:ptv}=-:) : how to ?

[ABClf]

Hello !

It should be easy but I don't get successful.

I have 3 pages A, B, C in MyGroup
one has -> EnLigne: [[url|url]]
second has empty ptv -> EnLigne:
third has nothing about EnLigne

In MyGroup.GroupFooter, I want to test if ptv EnLigne has a value, and
then, if yes, print :
!!!En Ligne
*{$:EnLigne}

In example given, one page should print the GroupFooter.

I tried several things with no success. This one, for example :

(:if {$:EnLigne}=-:) [expected translation : if ptv EnLigne is not empty]
!!!En Ligne
* {$:EnLigne}
(:ifend:)

More generally, I don't know how to evaluate a ptv with "if
conditional" : how to know whether a ptv is set no not ?

There is a discussion in the ML where some contributor said that :
(:ptv:1:)
(:if equal {$:ptv} -:)True(:ifend:)
(:if ! equal {$:ptv} -:)False(:ifend:)
should work.

At this time, I can't get it to work : it says always false.
(http://www.pmichaud.com/pipermail/pmwiki-users/2008-January/048869.html)

So, my question is : how to show or not to show something, according
to the value of some ptv in the page ?

Thank you,
Gilles.



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| A | de la langue française
| B | http://www.languefrancaise.net/
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