[ZPT] (newbie) conditional content based on request

[Evan Simpson]

From: "Peter Bengtsson" <mail@peterbe.com>
> Whats the difference between (if exists) and (exists) ?

Vanishing.  Today's release will eliminate these spellings.  The intent of
the former was to use the value of the path, if it exists, otherwise leave
the default.  This will now be spelled "a/b | default".  The second is meant
to simply test whether the path existed, returning true or false.  Most uses
of this should be replaceable with "a/b | nothing" or "exists:a/b"
(depending on what you want to do if "a/b" exists and is false).

Cheers,

Evan @ digicool