[Templates] disable undef interpolation

[Stuart Johnston]

Julio Otuyama wrote:
> Hello,
> Is there some way to disable the interpolation of TT in the case of an undef value?
> I dont want TT to remove the expression when there is an undef. Just keep the expression to be evaluated in a another step.
> This way I could execute TT as many times as I want, creating a "cache" for the next step. It is easier to debug the code.
> For instance:
> 
>   [% createddate %][% timesincecreated %]
> 
> The "createddate" could be replaced in the first step, but "timesincecreated" should be replaced only on request time, in a second step.
> Thanks,
> Julio

You can do this with the TAG_STYLE option or the TAGS directive.  Use a 
different style for each pass.

http://tt2.org/docs/manual/Config.html#section_TAG_STYLE