From: Kirk Haines <khaines@...>
Date: 2006-06-15T04:37:48+09:00
Subject: Re: Using YAML as a data DSL

On Wednesday 14 June 2006 11:26 am, Jatinder Singh wrote:

> YAML provides a way to persist objects in text format which is I believe
> very user friendly, so what I thought is that a user can create a file with
> above contents and then use YAML::load method to load above file's content
> in to ruby object.

I have an application for a customer that provides them with a system to store 
product information, photographs, inventory data, etc..., and then to search 
all of it in a freeform way.

Because different records might have different data fields which are 
important, I gave them a simple interface.  Data is entered as a YAML hash.  
Well, mostly, anyway.  To be fair, I am not actually using YAML to parse what 
is entered, because I don't want to allow anything other than

customer: Corona
description: Blinky buttons with a narrow profile and embossed face.

type key/value pairs.

However, the inspiration came from YAML and my use of YAML for config files.  
It's a simple enough format that they can get it right without too much 
difficulty, and it offers flexibility.

That said, if your application is going to be used by more than a small, 
select group of people, I would be hesitant to actually use YAML in the way 
that you suggest.  Perhaps I am overly paranoid, but I don't want to leave an 
application open to Joe ScriptKiddie's attempts to abuse YAML into doing 
painful things.  If I were going to go in that direction, I'd, at the very 
least, build a preprocessor of some sort to help make sure the content loaded 
into YAML fits the expected profile.  It would still make me nervous, though.


Kirk Haines