From: Robert Klemme <bob.news@...>
Date: 2004-08-22T07:25:48+09:00
Subject: Separation of Web Request and Response (was: Re: Idea: Webshare)


"Patrick May" <patrick@hexane.org> schrieb im Newsbeitrag
news:B73EE02E-F3B7-11D8-BFFE-000A95848050@hexane.org...

> P.S. <rant> About the only cgi design suggestion I see on ruby-talk
> that I outright disagree with is Request / Response.
>
> I experimented with this in Narf, and I think it is a mistake.  You end
> up with two objects, with alot of shared implementation code, that
> always go together, split apart for no practical reason.  I don't mind
> having Request / Response separated in the documentation, but splitting
> it in the code just adds typing.  When will you ever want a request
> without the response?  Martin Fowler has a name for this refactoring,
> but I don't have his book.
>
> The Java Servlet API is not one to imitate.  It's a design which solved
> the problem that Java was too slow to run as a CGI.  Given that ruby
> doesn't have that limitation, I'd rather design the API that makes
> building web apps easy and fun.
>
> Why bother with the API that made it possible to run web apps on a
> bloated os / programming language / platform / all around lemon? </rant>

There are in fact good reasons in favor of the request / response split.
First of all request and response are in fact two different things, so from
that point of view it's not a bad idea to separate them.  The interface of a
combined request response instance is likely to get too bloated.  There are
use cases where you only need the response (say, a page that displays the
current time) and there might be others where you don't need the response
(can't think of any at the moment though, some kind of upload maybe :-)).
Another reason why I liked the separation (in Java) is that you can easily
wrap only one of them (common with filters in Java, but similar things can
be done with Ruby, too); examples are filtering of whitespace from the
response and adding default values for request parameters.  If request and
response are encapsulated in a single instance this becomes much more
difficult to do - and the fun goes away. :-)

That are my 0.02 on the matter...

Kind regards

    robert