From: "J. Ryan Sobol" <ryansobol@...>
Date: 2005-12-28T04:05:44+09:00
Subject: Re: The Expert Ruby Programmer

On Dec 27, 2005, at 1:01 PM, Steve Litt wrote:
> I have a big problem with a few sentences in the preceding URL. Or  
> at least as
> I understand them. They seem to be advocating getting rid of config  
> files and
> putting all logic in code, at least my reading of the following  
> quotes:
>
> ============================================
> "A full Rails application probably has less total code than the XML  
> you'd need
> to configure the same application in other frameworks."
>
> "Rails strives to honor the Pragmatic Programmer's DRY Principle by  
> avoiding
> the extra work of configuration files and code annotations. You can  
> develop
> in real-time: make a change, and watch it work immediately.
>
> Forget XML. Everything in Rails, from templates to control flow to  
> business
> logic, is written in Ruby, the language of choice for programmers  
> who like to
> get the job done well (and leave work on time for a change)."
> ============================================
>
> Putting all your logic in code is nothing new. That's how it was  
> done in the
> 60's. By the 80's programmers created configuration files so that a  
> customer
> request for increasing the customer number field from 5 to 6 digits  
> wouldn't
> require recoding -- the user could change the config file. It  
> requires a lot
> more coding, but it makes for a much more resiliant application.
>
> Anyone can write a "simple" app if he or she puts all the logic in  
> code, and
> that programmer will be called every time a change is needed in  
> that code,
> even if the change is trivial.
>
> To me, the art of programming is anticipating likely changes and  
> needs, and
> putting facilities for those changes and needs in config files, so  
> that the
> change can be made with a simple tech support call instead of a  
> code change.
>
> I believe in data centered programming.
>
> Once again, perhaps I misunderstood the intent of the web page, but  
> if they're
> advocating moving logic from data to code, that's some advice I  
> will not
> follow.
>
> SteveT
>
> Steve Litt
> http://www.troubleshooters.com
> slitt@troubleshooters.com
>


I've actually used Rails in a few side projects and I have a  
different interpretation of those statements.  Rails packages the  
most common components of web development and automatically creates  
sensible defaults, which *can* be changed if necessary, in  
configuration files.  This is probably the biggest difference between  
Rails and many other web development frameworks / technologies.

For example, instead of the developer maintaining configuration files  
that define existing attributes in database tables, which tend to be  
volatile due to customer requests, Rails just queries the table  
during runtime and asks it what attributes it has.  In another  
example, instead of the developer maintaining a configuration file  
that defines the location of my application's templates files, Rails  
creates the directories and manages the same information internally.   
The default behavior in both these examples can be over-ridden, but  
there's seldom a reason to do so in the majority of cases.

Rails establishes a groovy synergy between these and other web  
development components that makes developing these kinds of  
applications easier.  I highly recommend you try if you do any  
serious web development.

~ ryan ~