[phpesp-dev] phpesp future expandability (xml)

[James E. F. <jf...@ac...>]

A few days ago I was chatting with the IT Lab guys
(greggmc, zorncj) about ways to make phpesp more flexible.
As you may have noticed, people frequently request the
ability to make forked (aka branching or conditional)
surveys, where the response to one question chooses what
additional questions are seen. In order to implement this
feature, the database schema would have to be changed to
hold more metadata. There have already been a few DB
changes, but I would like to find some solution to keep
this from continuing. Setting up the database seems to be
one of the biggest problems for users (besides windows
support). I propose that the survey storage model be
changed to XML. With XML, future metadata changes can be
easily accomplished by replacing the old DTD with a new
one, a simple 'cvs up' could do this (rather than fiddling
with mysql).

My idea for this is to store surveys on the filesystem in
XML, and when they are activated (or tested) the XML will
be "compiled" (using xsl?) to php. This way the xml doesn't
have to be transformed on each hit. Also by using XML
internally, import/export of surveys will be trivial. I
wrote up a DTD and some sample XML/XSL files a while
ago[1]; they aren't complete but might give you an idea of
where I was headed.

I also would like to pear-ize as much of phpesp as
possible. This means modularizing functionality, and
switching to OO-style code. However, we can make use of the
growing collection of existing Pear modules (like the Auth
module, and the XML modules). Even if this change doesn't
happen soon, I'd like developers to skim the Pear coding
standards[2] and start trying to follow them for all new
code.

[1] http://phpesp.sf.net/xml/
[2] http://pear.php.net/manual/en/standards.php

I'll be around on IRC if anyone would like to chat about
this, or post your thoughts on the list.

Thanks,
-James