Re: [htmltmpl] TT's support for methods and complex structures. Why not?

[Sam T. <sa...@tr...>]

On Mon, 18 Jul 2005, Mark Stosberg wrote:

> > #1 I can get behind.  #2 makes me itch.  There's a high potential for
> > abuse here since methods can have side-effects which would break the
> > straight data-path from code to template to output.
> 
> I'm also more interested in number 1 than number 2. Do you mean "get
> behind" as in: "go forth and prepare a patch ye feature requester"

I guess I mean if there was a module on CPAN that did this I might use
it.  I'm not presently inclined to include it in the core module, if
only because it's obviously something that would be easy to do in a
sub-class.

> In between the coder the designer is some kind of understanding about
> what valid token names are, usually provided by the programmer.
> 
> I think most often this communication is implicit because the programmer
> puts the tokens in the document in the first place. In this case,
> exactly how the tokens came to be isn't interest to the designer.

Right on.

> Wouldn't the method call support be sort of like coderef support that is
> already there?

Yes, although I'd wager that the percentage of anonymous subs that
have side-effects is much lower than the percentage of methods that
have side-effects.  I realize that either one could but methods just
seem more likely to encourage this abuse.

Although, if you want to get to the heart of the matter, code-ref
variables were not my idea.  I added them in response to a majority of
the users declaring their interest.  Sometimes I do that...

> It seems like it might even be implemented like that: as as callback
> which gets the method name passed in as a parameter.

Yes, I think that would be the easiest way.  HTML::Template::Expr
exploits code-ref variables to offer function calls, so why not
methods too?

-sam