From: Mark Hubbart <discordantus@...>
Date: 2005-09-11T19:11:55+09:00
Subject: Re: RCR to modify #puts and #print inside ERB

On 9/10/05, David A. Black <dblack@wobblini.net> wrote:
> Hi --
> 
> On Sun, 11 Sep 2005, Jay Levitt wrote:
> 
> > In article <49958C10-DAD0-4E7C-B9AB-44C6D314A637@refinery.com>,
> > gavin@refinery.com says...
> >> My personal mental model says that #puts is for outputting content
> >> that is the desired output of your program (unlike #warn). An ERB
> >> template is a parametrized program in its own right, and its output
> >> is the resulting string. If you want debug output, use #warn.
> >
> > Agreed.  I find it interesting that most of the responders to the thread
> > aren't active in the Rails group; Rails is where this sort of thing
> > *really* would be nice.
> 
> I love Rails and I use it quite a lot.  But I like ERB to behave
> in the consistent, non-special-cased way it now does, which is
> perfectly straightforward given how method calls work in Ruby (which
> is a matter of public record :-)  I also don't like the idea of
> changing things around in the language because the changes would suit
> a given application, project, or framework (though in this case, for
> me, that's a moot point because I don't think it would be suitable
> anyway).

I'm getting the idea that the people on each side of this discussion
disagree because they have different mental models of what ERB does,
and what a ERB document is:

1. ERB just implements very fancy, flexible, string interpolation.
or
2. ERB documents are executable code (actual programs), where text
prints itself, and code blocks get run.

#1 is, I gather, much like the JSP way (though I've never done JSP stuff)
#2 is much like PHP.

If you are in the #1  camp, I suspect you think this RCR would not be
all that much different from one allowing this:
"#{puts 23}" #==> "23\n"

If you are in camp #2, you probably just wonder why stuff you output
via #print or #puts doesn't end up with the rest of your ERB program's
output.

I'm in camp #2; I came to Ruby from PHP, and think of the template as
an actual program, an executable script with controlling statements
(Ruby code) embedded in self-printing text. I was shocked and greatly
disappointed when I found out that puts didn't work (yes, I thought it
was *broken*). I delved deeper and discovered that it was simply due
to an implementation issue; I assumed no one had fixed it because it
was too complicated a fix.

Now, I have a proposal: What if _erbout was made into a StringIO, and
we shifted the idea from an ERB template to an ERB program? Then would
it make sense for puts to output to _erbout?

cheers,
Mark

(my apologies if any part of this doesn't make sense, it's been a very long day)