From: Wai-Sun Chia <waisun.chia@...>
Date: 2002-08-12T17:08:13+09:00
Subject: Re: Handling forms on database driven websites

Philip Mak wrote:
<snip>
> 
> which looks considerably nicer, but still feels too tedious when I'm
> building a website that has many of these forms to make. I also find
> myself having to duplicate my data definitions; Ruby sees this:
> 
>         'name' => ['Name', Forms::Text, {'maxlength' => 20}],
>         'email' => ['E-mail Address', Forms::Email],
>         'phone' => ['Phone Number', Forms::Phone]
> 
> And the MySQL sees another data definition for the same data:
> 
>         name        VARCHAR(20)
>         email       VARCHAR(80)
>         phone       DECIMAL(10, 0)
> 
> So, I am still in search of the perfect, minimal-effort way to
> generate HTML for, and process the input of forms on a database-driven
> website.
> 
> Does anyone have any pointers to offer?
> 


> P.S. I've heard people here say that PostgreSQL is better than MySQL.
> How would it help in my situation?

Yes it is. It has long has many of the features that MySQL is only 
beginning to take place (i.e. FK, ACID, etc.). But I don't think it'll 
help in your case as yours is not a DB-related problem. It is a 
paradigm-shear between your language (Ruby) and your medium (MySQL).

This is as Ruby is a pure OO while MySQL or any RDBMS is not. The ideal 
case is to find a OODBMS and thus data will have a one-to-one mapping 
between Ruby and the OODBMS.

Having said that I do not know of any viable Opensourced OODBMS around 
(I'm very happy if someone could confirm otherwise). Therefore, you 
could do a second-best solution is to have another level of indirection, 
a meta-data-definition. I have done this before using XML, below is an 
oversimplified sample:

<name>
   <type>varchar</type>
   <maxlength>20</maxlength>
</name>

You could then write a Ruby layer to decode this and generate the Ruby 
class (which would be then be eval'ed dynamically later), and the 
MySQL/PostgreSQL SQL script.

You could then write a DTD or XMLschema to manage the integrity of your 
XML-based Metadata Definition.

After which you could generate a PageTemplate (it's great! I'm using it 
with fantastic results) form template, which could then be instantiated 
dynamically depending on what type of forms. This is an excellent 
solution if you have lots of similar forms, differing just is a couple 
of attributes or fields.


-- 
Wai-Sun "Squidster" Chia
Consulting & Integration
Linux/Unix/Web Developer Dude