Hi Kapil, (and fellow Zopatistas)
Well, it's been difficult, but I finally feel as if I'm on the
verge or understanding this a bit better..
Thank you for taking the time to explain this.
I would think, it's a fairly simple thing I'm trying to do.
Hehehe.. Famous last words.. huh?
So, anyway, I've been staying up till 2 am almost every night
trying to absorb as much of this as I can, but I have an (extensive)
web development, but not a programmer's background, and I'm very much
a Zope newbie, so I need to ask you some more questions.. I hope you
don't mind..
You can get a feel for what I am talking about by looking at any
of the programs or workshops on the website I manage,
www.msri.org.
Currently, I'm doing this site by rendering these fields of info
through templates into static pages in Frontier, but I'd like to
transition to Zope.
(Its the old webmaster's dream of the "self-maintaining
site" *LOL*)
So here's where I'm at so far.. I have built an Oracle 7
database to hold the event info.. Everything fine there, everything
works.. now for the fun stuff..
I have several tables in this "event" section of the
database, programs, workshops and talks. (there actually is one
other table for other kinds of events) Each kind of event is treated
somewhat differently in the schema. It's a very simple setup with
nothing exotic going on.. Logically, a given workshop is
usually tied to a program..and a given talk is usually tied to a
parent workshop.
I have been successful in setting up the basic web-database
interaction. I made the basic insert and query forms that are
described in the ZSQL Users Guide, and as I said in my previous
posting my next goal is to be able to create separate documents from
the data in the individual records that are inserted into the
tables.. I'd like to be able to search them along with the other Zope
documents on the site, at once, (using a ZCatalog..hopefully) I also
need to be able to quickly build several different kinds of
automatically-maintained lists from SQL queries that home in on
various subsets of the event data. (Ultimately, this system will be
expanded to handle "people" data, which will involve some
very large lists of people spanning over 20 years, so this system
needs to have decent performance with large datasets...But, even
then, the result set of a given query will always be quite
small..)
Starting with (on the insert record side) I have an SQL Method
for each event type that describes the permissable arguments, and the
code describing the multi-field insert.
(I have a sequence and trigger already working on the database
side of things that implements a unique ID -the primary key- for each
new program, so the ID is not one of the arguments passed through the
ZSQL Method..should I change this? - I could do this some other
way..)
I also have another SQL method for each type of event that does
a select * from <event_type> so that I can implement pulldowns
in the select form for the child workshops of a program. (This is
really nice and is one of the reasons I think Zope will be great for
building a highly useable web interface to this database,
widgets like this make it easy to keep referential integrity..)
Then, one (in the case of the event types without possible
"parents") or both of the SQL Methods are called in an DTML
Document input form. When the form is submitted a DTML Method is
triggered, which right now only shows an acknowledging thank you to
the person who submits the information.
So, if I understand you correctly, **I should then use that
action to create a class that is tied to the primary key of the
database table. Is there an example somewhere of this RDBMS
table-keyed "automatic" creation of ZClasses or DTML
documents?*
I think ZClasses would be preferable because there are
several kinds of event pages I'd like to generate for each kind of
event.. (for example, sometimes we have short-term housing
information we want to show, and a few weeks before a given event, as
more information becomes available, I'd like to be able to have it
added .. For example, as an event time nears, I almost always have to
put up schedules of the talks in a given workshop..)
Anyway, if you have the time and can think of any handy pointers
to documentation or relevant examples, Id appreciate it.. But even if
not, you already have given me a good start.. It shouldn't be
very hard, but even though I've been putting in a lot of time
searching, finding information has been difficult for me.. The
closest I could find to what I want to do is the (very) few
snippets of information available about "pluggable brains".
But there isn't even a HOWTO on this, a question that should be a
common question.. If anyone has any pointers for a beginner.
I'd be really grateful..
Thank you..
Chris
I really appreciate your help..
Chris
[EMAIL PROTECTED]
Some considerations.
1. Duplicating data is bad.
2. Let the RDMBS do as much of the processing as possible.
A possible solution (TMTOWTDI):
create a dtml method 'create event'. its basically an encapsulation to
simulate triggers. in this method make your call to the insertion of the
data into the sql db. after that call you can create a ZClass or DTML
document with the property that stores the primary key of the data
record in the DB (if you do it as a dtml doc, you either want to clone,
or pass its body, check out the ZQR). this is your basic association of
your objects and the sql data. in a dtml method that lives above your
objects have a body that basically calls a retrieval sql on the db which
takes an arg for the id. The body of your dtml doc/ZClass(index_html)
calls this method for presentation of its data passing its property as
an arg. you can arrange your objects in whatever heirarchy you want as
they will acquire the dtml method and the sql methods for presentation
(or put it in the zclass). For deletion create a similiar trigger
encapsulation method, delete row, delete object.
caveat. DON't use this to display lots of events on a page (hideous
performance). you're much better off going to the db directly and
grabbing all the results you need perhaps with python brain for extra
presentation info.
Cheers
Kapil
