The core active tag library is modelled after some of the functionality that
exists in Java's JSTL. It
is still in the preliminary design stages, and more tags are expected.
Currently, it provides the following active tags:
<print val=expression
[encode=false|html|url] [default=expression] />
Outputs the value of the val expression. If there is an error
and a default is provided, the default will be evaluated instead. The
output may be encoded to be HTML- or URL-safe, depending on the
encode attribute.
<let var=string
val=expression /> Sets the variable var to
the value val in the tag context.
<let var=string
val=expression> ... </let> Same as above,
except that the scope of the variable is that of the tag body, and the value
of the variable, if it existed prior to the start tag, is restored after the
end tag.
<unlet var=string />
Unset (i.e. delete) the variable var in the tag context.
<if test=expression> ...
</if> Evaluate test and conditionally
process body of tag.
<for items=expression
[var=string] [counter=string]> ...
</for> Iterate through items and process the
body each time. The current item can optionally be stored in variable named
by var, and the current iteration number (starting at zero) can
optionally be stored in a variable named by counter.