EnzymeTemplates slash-style comments demo.

"The self is that relation which relates itself to itself" 
				-- Kierkegaard

One of the new features of EnzymeTemplates is the ability to specify a new
kind of relation, called a reflexive relation. This is for database tables
that relate themselves to themselves. This usually results in a tree 
structure. 

Perhaps an example will demonstrate.

Slash (http://slashcode.com or http://phpslash.org) uses a comments table that
looks like this (simplified):

TABLE comments (
	cid int,
	pid int,
	subject varchar,
	...
	etc.
	...
);

Now, every comment has a cid. The pid can be null. The pid is the cid of the 
"parent" comment for every comment. Thus, pid is actually a lookup into the
comments table. Thus, each comment has one parent and potentiall many children.

Assume we have a comment with cid Xc and pid Xp. 
To determine its parent comment, simply

SELECT * FROM comments WHERE comments.cid = Xp;

To determine its children comments, simply

SELECT * FROM comments WHERE comments.pid = Xc;

This is what the Reflexive Relation does for you, automatically. You just
specify what field the table should "reflex" on, and you get a tree structure
automatically. See comment_objects.inc for the details of how to specify this.

Thus, every comment object has two special objects, one called "Parent" and
the other called "Comments" - the former is a single object of type Comment,
and the latter is an array of Comment objects. Simple, right? You bet.

To install the sample data, just create a table called "comment" and do:

% mysql -p comment < comment_data.sql

This will create a database with a few bogus comments. You can view these
comments, and add your own by pointing your web browser at the demo5.php3
file.